LG RCWF P(200-3000RT) Centrifugal Chiller Operation & Maintenance Manual

OPERATION & MAINTENANCE MANUAL

Water-Cooled Centrifugal Chiller

Please read this installation manual completely for safety before installing the product.

The purpose of this manual is to keep the user safe and to prevent any property damage. After reading this installation manual, please retain it for future reference thoroughly Installation work must be performed in accordance with this installation manual by authorized personnel only.

Model : RCWF***P(200~3000RT) www.lge.com

P/NO : MFL68929303 (Rev 0)

2

For your records

Staple your receipt to this page in case you need it to prove the date of purchase or for warranty purposes. Write the model number and the serial number here:

Model number :

Serial number :

You can find them on a label on the side of each unit.

Dealer’s name :

Date of purchase :

1. CAUTIONS FOR SAFETY _ WARNING/CAUTION

3


It can be dangerous when moving, installing and placing the system for its high pressure, electric devices and heavy weight especially when lifting the unit in a limited space(rooftop, lifted structure, etc.).

Please read carefully the warnings and cautions on this manual and the labels attached on the unit, and follow the instructions.

Please follow the following instructions to prevent any injury or property damage

• It may result in an injury or damages when neglecting the instructions on in this manual.

The seriousness of the result can be classified as the following signs.

• Please note that any failure of system resulted by user’s careless maintenance, natural disaster or the failure of the power cable shall not be warranted regardless of the warranty period.

• Please note that any part of this manual can be revised without notice for the product improvement.

!

WARNING

It can result in serious injury or death when the directions are ignored.

!

CAUTION

It can result in minor injury or product damage when the directions are ignored.

The meanings of the symbols used in this manual are as follows.

!

This is the symbol to call attention for the issues and operations that may cause danger.

To prevent the occurrence of the danger, read carefully and follow the instructions.

This is the symbol showing the how-to-use instruction in order to prevent danger.

Follow the direction.

1-1. WARNING

• Have all electric work done by a licensed electrician according to "Electric Facility Engineering Standard" and "Interior

Wire Regulations" and the instructions given in this manual and always use a special circuit.

- If the power source capacity is inadequate or electric work is performed improperly, electric shock or fire may result.

• Ask the dealer or an authorized technician to install the chiller unit.

- Improper installation by the user may result in water leakage, electric shock, or fire.

• For re-installation of the installed product, always contact a dealer or an Authorized Service Center.

- There is risk of fire, electric shock, explosion, or injury.

• Make sure to equip the circuit breaker and fuse.

- Improper wiring or installation may cause fire or electric shock.

• Do not disassemble, repair or reconfigure the unit.

- LG Electronics is not responsible for the any damage or loss from the arbitrary disassembly, repair or reconfiguration of the unit.

• Make sure to ground the unit properly.

- There is risk of fire or electric shock.

• Do not store or use flammable gas or combustibles near the chiller unit

- There is risk of fire or failure of product.

• Do not reconstruct to change the settings of the protection devices.

- If the pressure switch, thermal switch, or other protection device is shorted and operated forcibly, or parts other than those specified by LGE are used, fire or explosion may result.

• Install the unit on a foundation where the heavy weight can be supported.

- Insufficient strength of the foundation to support the chiller operation may cause the unit failure or injury.

4


• Installing the product in small space requires separate measures to keep the leakage of the refrigerant within the safety limits in case of any leakage.

- Consult the authorized dealer for appropriate measures to prevent the refrigerant leakage from exceeding the safety limits. The leakage of refrigerant exceeding the safety limit may result in dangerous situations due to the lack of oxygen level in the room.

• Securely install the cover of control box and the panel.

- If the cover and panel are not installed securely, dust or water may enter the unit and fire or electric shock may result.

• Do not operate the unit arbitrarily.

- Incorrect operation of the unit may cause dangerous situations such as unit defects, leakage or electric shock. Always consult the authorized dealer.

• Do not use damaged circuit breaker or fuse works correctly all the time.

- It may cause fire, electric shock or injury.

• Keep the control panel from any water getting in.

- Do not wash the control panel with water. It can cause electric shock or defects.

• When the product is soaked (flooded or submerged), contact an Authorized Service Center.


• Use a dedicated outlet for this unit.


• Make sure to charge only the exclusive refrigerant R134a when installing or moving to other place.

- If a different refrigerant or air is mixed with the original refrigerant, the refrigerant cycle may malfunction and the unit may be damaged.

• Do not touch the power switch with wet hands.

- There is risk of fire, electric shock, explosion, or injury.

• Ventilate before operating the chiller unit when gas leaked out.

- Do not use a phone or operate the power switch at this time. It may cause fire or explosion.

• Do not put any heavy object on the top of the unit or climb on the unit.

- It may cause defects or injury.

• Be careful with the rotating part.

- Do not put your fingers or a stick to the rotating part. It can cause injury.

• Use the fuse and circuit breaker with rated capacity.

- It may cause fire and defects.

• Redesigning the control box is prohibited.

- Lock the control box with possible locking device and if you need to open the control box inevitably, turn off the main power first.

• Do not touch the wiring or a parts inside the panel.

- It may cause electric shock, fire or defects.

• Follow the permitted pressure level

- Follow the regulated pressure for cold water, cooling water, refrigerant etc.

• Do not change the set values.

- Do not change the set values of the controller and safety devices. Operating with inappropriate setting can cause damages. When changing the setting values, please consult with the specialist.

• Be careful of fire, earthquake and lightening.

- In case of any natural disaster such as fire, earthquake or lightening, immediately stop operating the unit. If you continue to operate the unit, it can cause a fire or electronic shock.

• Follow all safety code.

- When operate the chiller, follow the precautions on the manual, tag, sticker and label.

• Use of undesignated refrigerant and oil is prohibited.

- Do not use undesignated refrigerant, freezer oil and brine. It may cause serious effect to the compressor and parts defect.

• During the installation and service, shut down the power supply.

- Electric shock can cause injury and death. Mark and check all switches so that the power is not recovered until the work is completed.


5

• Wear safety equipment

- Wear safety glasses and work gloves. Be careful when installing or operating the chiller and operating the electrical components.

• Always run fluid through heat exchangers when adding or removing refrigerant charge.

- Potential damage of the tube within the heat exchanger can be prevented. Use Appropriate brine solution in cooler fluid loops to prevent the freezing of heat exchangers when equipment is exposed to temperature below

0°C.

• Do not vent refrigerant relief valves within a building.

- Outlet from relief valves must be vented outdoors in accordance with the latest edition of ANSI/ASHRAE(American National Standards Institute/American Society of Heating, Refrigeration and Air Conditioning Engineers) 15

(Safety Code for Mechanical Refrigeration). The accumulation of refrigerant in an enclosed space can displace oxygen and cause asphyxiation. Provide adequate ventilation in enclosed or low overhead areas. Inhalation of high concentrations of refrigerant gas is harmful and may cause heart irregularities, unconsciousness or death. Misuse can be critical. Refrigerant gas is heavier than air and reduces the level of oxygen. It can cause irritation to eyes and skin.

• Be careful of water leakage.

- In case of any water leakage in the pump or pipe, immediately stop operating the unit. It may cause electric shock, electricity leakage or defects. Be careful of electric shock.

• Always ground the chiller during installation.

- It may cause electric shock.

• Do not leave refrigerant system open to air any longer than necessary.

- If the repair cannot be completed, seal the circuits to prevent any contamination or rust within the product, and charge dry nitrogen.

• Do not reuse compressor oil.

- It can damage the product.

• During installation, make the specified grounding before supplying the power, and during the dismantling, remove the grounding line at the end of the task.

• Use appropriate meters for measurement. Otherwise, it may cause injury or electric shock.

• Check all power connected to the control panel or starter panel to be shut off while applying the power.


• Make sure to discharge the electric current before inspection or repair work.

- It may cause injury or electric shock.

• Do not open the 2nd phase side of the current transformer when power is on.

- High voltage could be discharged causing an electric shock.

• Remove foreign objects(working tools, wires, bolts, washers) after installation, inspection, and repair work.

- They may cause injury, fire, or damage.

• When using a condenser, make sure to verify the complete discharge before applying the power again. (Re-powering within 5 min. is prohibited.)

- It may cause electric shock, fire, damage, or malfunction.

• Change the condenser in case that the expansion exceeds the recommended limit.

- It may cause electric shock, fire, damage, or malfunction.

6


1-2. CAUTION

Operation & Maintenance

• Always check for gas(refrigerant) leakage after installation or repair of product.

- Low refrigerant levels may cause failure of product.

• Do not install the unit where combustible gas may leak.

- There is risk of fire or failure of product

• Keep level even when installing the product.

- Unleveled refrigerant can cause problems to the product.

• Do not use the product for special usage or location such as preserving animal/plant, precision machine, artifact, etc.

- It may cause property damage.

• Use exclusive wire for the product. Use power cables of sufficient current carring capacity and rating.

- It may cause fire and electric shock.

• When installing the unit in a hospital, communication station, or similar place, provide sufficient protection against noise.

- The inverter equipment, private power generator, high-frequency medical equipment, or radio communication equipment may cause the chiller to operate erroneously, or fail to operate. On the other hand, the chiller may affect such equipment by creating noise that disturbs medical treatment or image broadcasting.

• To protect the product from corrosion, do not install the product where it is exposed to sea wind(salt spray) directly.

If necessary, please install shield.

- It may cause product deformation and defects.

• Make the connections securely so that the outside force of the cable may not be applied to the terminals.

- Inadequate connection and fastening may generate heat and cause fire. If the power cable got damaged, do not directly replace it, but call the service center for replacement first.

• Do not use the product in special environments.

- Oil, steam and sulfuric steam can deteriorate the product performance or cause damage to the parts.

• Be careful when transporting the product.

- When carrying the chiller, always consult with the specialized expert.

• When transporting the chiller, always follow the methods described in the manual.

- If not, it can cause overturn, fall etc.

• Do not touch any of the refrigerant piping during and after operation.

- Pipe during and after the operation can be hot or cold depending on the condition of the refrigerant flowing through the refrigerant pipe, compressor and refrigerant cycle parts.

Touching the pipes at this time can cause burns or frostbites.

• Turn on the main power 12 hours before starting to operate the product.

- If you operate the product immediately after turning on the main power, it can severely damage the internal parts.

Keep the main power on while operating.

• Do not immediately turn off the main power after the product stops operating.

- Wait at least 5 minutes before turning off the main power. Failure to do so can cause water leak or other issues.

• Do not operate the product with the panel or safety devices removed.

- Rotating parts or high temperature/pressure parts can cause safety accidents.

• Be careful when disposing the product.

- When disposing the chiller, request to the specialized expert.

• Use a firm stool or ladder when cleaning or maintaining the chiller.

- It may cause an injury.

• Be careful of high temperature.

- Be careful not to make body contact to the parts of the chiller in high temperature.

It may cause a burn.

• Be careful of high voltage.

- Install separate wiring for the power and always install and use dedicated power supply and circuit breaker.

It can cause electric shock and fire.


7

• Be careful of chiller installation.

- Keep enough clearance around the product for service and especially for air cooling type, install the product at well ventilated location where there is no obstacle.

• Harsh chemical, household bleach or acid cleaner should not used to clean outdoor or indoor coils of any kind.

- These cleaners can be very difficult to rinse out of the coil and can accelerate corrosion at the fin/tube interface where dissimilar materials are in contact. Use environment friendly cleaner.

• Be careful when restarting the product.

- When a safety device is triggered, remove the cause and then restart the product. Repeating the operation arbitrarily can cause fire and defect.

• Use appropriate tools.

- Use tools appropriate for the repair work and calibrate the measuring devices accurately before using. Using inappropriate tools can cause an accident.

• Be careful of sound and odor.

- If you hear a weird sound or smell an odor, immediately stop operating the system and contact the service center.

It may cause fire, explosion or injury.

• Be careful of injury.

- Check the safety label of the safety device. Follow the above precautions and the contents in the label. It may cause fire and injury. To prevent the formation of the condensed water, the pipe connected to the evaporator as well as the evaporator itself should be well insulated.

• Check.

- Perform periodic checks. If any problem occurs, stop the operation and contact the service center. Insufficient check may cause fire, explosion or error.

• Do not attempt to bypass or alter any of the factory wiring.

- Any compressor operation in the reverse direction will result in a compressor failure that will require compressor replacement.

• Do not use jumpers or other tools to short out components, or bypass the parts differently from recommended procedures.

- Short-circuiting the control board ground line with other wires can damage the electric module or electric components.

• Water must be within design flow limits, and should be treated cleanly.

- This make it possible to ensure proper machine performance and reduce the potential of tubing damage due to corrosion, scaling, erosion and algae. LG Electronics is not responsible for any damage caused by cooling water not treated or improperly treated.

• Consult a water treatment specialist for proper treatment procedures.

- Hard scale may require chemical treatment for its prevention or remove.

• Do not overcharge refrigerant to the system.

- Refrigerant overcharging results in higher discharge pressure with higher cooling fluid consumption. Also it can damage the compressor and increase the power consumption. Also it can damage the compressor and increase the power consumption.

• Do not add different type of oil.

- It may cause abnormal operation of chiller.

• Turn controller power off before service work.

- It secures safety and prevents damage to the controller.

• Maintain the compressor oil pressure to normal level.

- Use proper safety precautions whem relieving pressure.

• Welding the evaporator head or nozzle part is not recommended.

- If the part requires welding, remove the chilled water flow switch and entering/leaving fluid thermistors before welding.

- After the welding is completed, reinstall the flow switch and thermistors.

- Failure to remove these devices may cause component damage.

• Do not open the circuit breaker arbitrarily during the operation.

- It may cause damage or malfunction.

8


• Do not operate with wet hand.


• During maintenance work, check whether all of the power lines connected to the control panel or starter panel are interrupted.


• When power is on, do not open the door of control panel or starter panel, and protective cover.


• Do not open the circuit breaker without permission while running.


• Tighten bolts and screws with the specified torque.

- Otherwise, it may cause fire, damage, or malfunction.

• Do not change electric or control devices arbitrarily.

- It may cause fire, damage, or malfunction.

• Only the persons who have sufficiently studied the user's manual should operate the control panel or starter panel.

- Otherwise, it may cause injury, fire, malfunction, or damage.

• Do not perform welding work near cables connected to the main unit.

- Otherwise, it may cause fire or damage.

• Connect only the input/output signal cables specified in the drawing to the control panel or starter panel.

- Otherwise, it may cause malfunction or damage.

• Use the rated electrical cables.

- If not, it may cause fire or damage.

• Use specified parts for repair.

- If not, it may cause fire or damage.

• Install the machine, control panel, and starter panel at a place where there is no combustible material.

- Otherwise, it may cause fire.

• Do not exceed the voltage supply limit described in the relevant manual.

- Otherwise, it may cause damage or malfunction.

• Connect the signal cables connected to the control devices following the circuit diagram.


• Do not store the product in a place where is a flooding risk or a lot of moisture.


• Do not use the indoor control panel or starter panel outside of the building.


Contents

9

Thank you for purchasing the water cooled centrifugal chiller of LG Electronics.

Installation as instructed after reading this manual will ensure the safety, convenience and long lifetime of the unit.

Please read this manual carefully for the correct installation and proper operation of the centrifugal chiller.

Once the installation completed, please run the start-up test and inspect according to the operating & maintenance manual. h This manual describes the introduction, control, start-up test, maintenance, and trouble shooting of the chiller.

CONTENTS

3

6

3

1. CAUTIONS FOR SAFETY

_ WARNING/CAUTION

1-1. WARNING

1-2. CAUTION

10

2. INTRODUCTION

10

10

11

11

12

2-1. General Information

2-2. System structure

2-3. Nomenclature

2-4. Name plate

2-5. Main unit conversions

27

28

29

68

71

14

3. STRUCTURE OF SINGLE

STAGE CENTRIFUGAL

CHILLER

14

15

3-1. Cycle of the chiller

3-2. Main components of the two stage centrifugal chiller

21

4. CONTROL SYSTEM

21

26

4-1. Components of control panel and main parts

4-2. Components of starter panel and main parts

4-3. Basic control algorithm

4-4. BMS support function

4-5. Control Screen (Product function)

4-6. Startup and Control sequence

4-7. Product protection function

74

5. START-UP

74

76

83

86

5-1. Delivery and Installation Check

5-2. Preparation for start-up

5-3. Start-up

5-4. Startup procedure after long-period of stoppage

5-5. System Shutdown

87

88

6. Maintenance

88

92

98

6-1. Maintenance criteria

6-2. Periodic maintenance

6-3. Maintenance during off-season

99 6-4. Annual maintenance(1/2)

100

6-4. Table for Annual maintenance(2/2)

101

6-4. Table for Annual maintenance

102

6-5. Oil maintenance

104 6-6. General Maintenance

107

7. Troubleshooting

107 7-1. Causes and actions for alarms

120

8. Operation inspection record

120

8-1. Check list for operation record

10

2. INTRODUCTION

2. INTRODUCTION

2-1. General Information

This manual describes the installation of water-cooled Single stage Centrifugal chiller using R-134a refrigerant and

X30 controller applied.

2-2. System structure

Figure 1 shows the general parts location and components of the Single stage Centrifugal Chiller.

The location of control panel, type of water box, direction of inlet/outlet of the chilled/cooling water and some of the pipes may vary by model or the customer specifications. Please confirm with the approved drawings for the site.

Front view

1. Evaporator relief valve

2. Condenser relief valve

3. Lifting hole (Compressor)

4. Terminal box for compressor motor

5. Main name plate

6. Control panel

7. Lifting hole (Condenser)

8. Condenser name plate

9. Service valve

10. Filter dryer

11. Sight glass

12. Condenser sight glass

13. Refrigerant return line

(Orifice + Butterfly valve)

14. Wire tray (optional)

15. Service valve

16. Air vent (for Cooling water)

17. Drain (for Cooling water)

18. Bracket for combining Heat exchanger

Rear view

19. Oil filter

20. Oil tank sight glass

21. Chain cover

22. Actuator (Guide vane)

23. Sight glass (Compressor inlet)

24. Chilled water temperature sensor

25. Cooling water temperature sensor

26. Cooling water differential pressure switch

27. Chilled water differential pressure switch

28. Drain (for Chilled water)

29. Air vent (for Chilled water)

30. Evaporator sight glass

31. Evaporator name plate

32. Lifting hole (Evaporator)

33. Sight glass (Motor)

Figure 1. Components of Single stage Centrifugal Chiller

2. INTRODUCTION

11

2-3. Nomenclature

The nomenclature of the Centrifugal Chiller is as shown in the figure 2.

R : R-134a

1 : R123

W : Water-Cooled

Cooling Only

K : Water-Cooled

Heating pump

Nominal tons of compressor

10RT

⇨ 001

100RT

⇨ 010

1000RT

⇨ 100

Max operating pressure of

Chilled water and Cooling water

A : Chilled water 10kg/cm

2

Cooling water 10kg/cm

2

B : Chilled water 16kg/cm

2


2

C : Chilled water 20kg/cm

2


2

D : Chilled water 8kg/cm

2


2

E : Others

R C W F 100 P A 1 1

C : Chiller

F: Centrifugal compressor

[Single stage]

P: Single stage

Standard

L: Single stage Ice

Thermal Storage

B: Single stage

Nuclear Standard

S: Single stage Special

Specification

(ex.: Explosion-proof type, Drip-proof type, etc.)

R: Single stage Heat

Recovery type

Number of compressor

Development order

Figure 2. Nomenclature

ۃ

ۄ

ۅ

ڿ

ۀ

ہ

ۂ

ڼ

ڽ

ھ

ڸ

ڹ

ں

ڻ

2-4. Name plate

Name plate for the unit is attached on the right side of the control panel. General information of the product can be achieved from the plate, and the information can be used for quicker service later.

① Model name

② Refrigerant

③ Cooling capacity

④ Power and current required for motor

⑤ Manufacture's serial number

⑥ Internal pressure test pressure

⑦ Maximum working pressure (Design pressure)

⑧ Volume of Evaporator

⑨ Volume of Condenser

⑩ Power electricity

⑪ Control electricity

⑫ Temperatures of Chilled water inlet/outlet

⑬ Temperatures of Cooling water inlet/outlet

⑭ Maximum pressure of chilled water and cooling water

Fig. 3. Name plate

°F

28

29

30

24

25

26

27

20

21

22

23

16

17

18

19

12

13

14

15

8

9

10

11

6

7

4

5

1

2

3

12

2. INTRODUCTION

2-5. Main unit conversions

Temperature conversion table (°F

↔ °C)

• °F = (9/5 x °C) + 32

• °C = 5/9 x (°F - 32)

°C

-4.4

-3.9

-3.3

-2.8

-2.2

-1.7

-1.1

-6.7

-6.1

-5.6

-5.0

-8.9

-8.3

-7.8

-7.2

-13.3

-12.8

-12.2

-11.7

-11.1

-10.6

-10.0

-9.4

-17.2

-16.7

-16.1

-15.6

-15.0

-14.4

-13.9

°F

57

58

59

60

53

54

55

56

50

51

52

46

47

48

49

42

43

44

45

38

39

40

41

34

35

36

37

31

32

33

°C

13.9

14.4

15.0

15.6

11.7

12.2

12.8

13.3

7.8

8.3

8.9

9.4

10.0

10.6

11.1

5.6

6.1

6.7

7.2

3.3

3.9

4.4

5.0

-0.6

0

0.6

1.1

1.7

2.2

2.8

°F

87

88

89

90

83

84

85

86

79

80

81

82

75

76

77

78

71

72

73

74

68

69

70

64

65

66

67

61

62

63

°C

30.6

31.1

31.7

32.2

28.3

28.9

29.4

30.0

26.1

26.7

27.2

27.8

23.9

24.4

25.0

25.6

21.7

22.2

22.8

23.3

19.4

20.0

20.6

21.1

16.1

16.7

17.2

17.8

18.3

18.9

Table 1. Temperature conversion table

°F

117

118

119

120

113

114

115

116

109

110

111

112

105

106

107

108

101

102

103

104

97

98

99

100

91

92

93

94

95

96

°C

47.2

47.8

48.3

48.9

45.0

45.6

46.1

46.7

42.8

43.3

43.9

44.4

40.6

41.1

41.7

42.2

38.3

38.9

39.4

40.0

36.1

36.7

37.2

37.9

32.8

33.3

33.9

34.4

35.0

35.6

°C

63.9

64.4

65.0

65.6

61.7

62.2

62.8

63.3

59.4

60.0

60.6

61.1

57.2

57.8

58.3

58.9

55.0

55.6

56.1

56.7

52.8

53.3

53.9

54.4

49.4

50.0

50.6

51.1

51.7

52.2

°F

147

148

149

150

143

144

145

146

139

140

141

142

135

136

137

138

131

132

133

134

127

128

129

130

121

122

123

124

125

126

2. INTRODUCTION

13

Pressure conversion table (lb/in

2

↔ kg/cm

2

)

• lb/in

2

= psi ex) 1 lb/in

2

= 0.07030696 kg/cm

2 lb/in

2

29

30

31

32

25

26

27

28

21

22

23

24

17

18

19

20

37

38

39

40

33

34

35

36

13

14

15

16

9

10

11

12

7

8

5

6

3

4

1

2 kg/cm

2

1.758

1.828

1.898

1.969

2.039

2.109

2.180

2.250

1.195

1.266

1.336

1.406

1.477

1.547

1.617

1.687

2.320

2.390

2.461

2.531

2.601

2.672

2.742

2.812

0.633

0.703

0.773

0.844

0.914

0.984

1.055

1.125

0.070

0.141

0.211

0.281

0.352

0.422

0.492

0.563

lb/in

2

69

70

71

72

65

66

67

68

61

62

63

64

57

58

59

60

77

78

79

80

73

74

75

76

53

54

55

56

49

50

51

52

45

46

47

48

41

42

43

44 kg/cm

2

7.382

7.453

7.523

7.593

7.663

7.734

7.804

7.874

6.820

6.890

6.968

7.031

7.101

7.171

7.242

7.312

7.945

8.015

8.085

8.156

8.226

8.296

8.367

8.437

6.257

6.328

6.398

6.468

6.539

6.609

6.679

6.750

5.695

5.765

5.836

5.906

5.976

6.046

6.117

6.187

Table 2. Pressure conversion table kg/cm

2

4.570

4.640

4.711

4.781

4.851

4.921

4.992

5.062

4.008

4.078

4.148

4.218

4.289

4.359

4.429

4.500

5.132

5.203

5.273

5.343

5.414

5.484

5.554

5.625

3.445

3.515

3.586

3.646

3.726

3.797

3.867

3.987

2.883

2.953

3.023

3.094

3.164

3.234

3.304

3.375

lb/in

2

109

110

111

112

105

106

107

108

101

102

103

104

97

98

99

100

117

118

119

120

113

114

115

116

93

94

95

96

89

90

91

92

85

86

87

88

81

82

83

84 lb/in

2

149

150

151

152

145

146

147

148

141

142

143

144

137

138

139

140

157

158

159

160

153

154

155

156

133

134

135

136

129

130

131

132

125

126

127

128

121

122

123

124 lb/in

2

189

190

191

192

185

186

187

188

181

182

183

184

177

178

179

180

197

198

199

200

193

194

195

196

173

174

175

176

169

170

171

172

165

166

167

168

161

162

163

164 kg/cm

2

10.19

10.26

10.34

10.41

10.48

10.55

10.62

10.69

9.632

9.702

9.773

9.843

9.913

9.984

10.05

10.12

10.76

10.83

10.90

10.97

11.04

11.11

11.18

11.25

9.070

9.140

9.210

9.281

9.351

9.421

9.491

9.562

8.507

8.577

8.648

8.718

8.788

8.859

8.929

8.999

kg/cm

2

13.01

13.08

13.15

13.22

13.29

13.36

13.43

13.50

12.44

12.51

12.58

12.66

12.73

12.80

12.87

12.94

13.57

13.64

13.71

13.78

13.85

13.92

13.99

14.06

11.88

11.95

12.02

12.09

12.16

12.23

12.30

12.37

11.32

11.39

11.46

11.53

11.60

11.67

11.74

11.81

14

3. STRUCTURE OF TWO STAGE CENTRIFUGAL CHILLER

3. STRUCTURE OF SINGLE STAGE CENTRIFUGAL

CHILLER

3-1. Cycle of the chiller

Single stage Standard Centrifugal Chiller

Cycle of the Centrifugal chiller is generally used for reciprocating same form as a screw refrigeration cycle, uses a high-pressure refrigerant R-134a. In this cycle, as shown in the Figure 1-1, the low temperature and low pressure refrigerant gas vaporized from the evaporator goes through guide vane and taken into the impeller of the compressor.

The amount of gas taken in at this time is adjusted by the opening of the guide vane to control the chiller capacity.

The refrigerant gas taken into the impeller is compressed to high temperature and high pressure refrigerant gas, discharged to condenser, and condensed after losing heat by cooling water in the condenser heat transfer tubes. The condensed refrigerant liquid goes through the orifice and goes into the lower part of the evaporator, is distributed evenly through all length of the evaporator by the distribution plate, and is evaporated after taking heat from the chilled water flowing inside the evaporator heat transfer tubes, and the same cycle is repeated. Part of the refrigerant liquid over-cooled in the condenser flows through valve, filter, sight glass, and is separated and flows to motor cooling and oil cooling system. The refrigerant liquid that entered the motor is sprayed to cool down the motor coil and returns to the evaporator. The refrigerant flowing to the oil cooling system flows to the plate type heat exchanger (oil cooler), and the refrigerant leaving the heat exchanger returns to the evaporator.

Compressor

Chilled water outlet

Chilled water inlet

Condenser

Cooling water inlet

Cooling water outlet

Orifice

Fig 4. Single stage centrifugal chiller

Evaporator

Refrigerant liquid

Refrigerant gas


15

3-2. Main components of the two stage centrifugal chiller

Compressor

Fig 5. Hermetic single stage high-speed compressor

*The single stage turbo chiller compressor is composed of an impeller, bearing, diffuser, capacity control device and high-speed gear. The low temperature and low pressured gas taken from the evaporator, goes through impeller, diffuser and is finally discharged to the condenser as high temperature high pressure gas.

The characteristics of the main components are as follows.

1. Impeller

- The vane of impeller designed aerodynamically based on the 3D fluid analysis, guarantees the reliability in any operational condition.

- To minimize vibration, the impeller takes on the dynamic balancing work. It also guarantees the overall reliability of the impellers by taking the strength test, hardness test, and non-destructive test.

2. Bearings

- Bearings are composed of a bearing in the motor axis, radial bearings and thrust bearings on the impeller axis.

- Bearings are made of white metal to achieve persistence and corrosion resistance. It is designed to be used safely avoiding metal to metal contact during operation as the lubricating structure of Figure 8.

- To increase the reliability of the journal bearings, Offset type and 3-Lobe type bearings are applied.

3. Capacity control device

- It adjusts the refrigerant amount taken through the compressor inlet to adjust the capacity of the chiller, and it adjusts the opening of the vanes using the external actuator.

- The amount of refrigerant taken in is adjusted according to the set of chilled water outlet temperature.

16


Heat exchanger

Heat exchanger of single stage centrifugal chiller is composed of two shell type for easy separation into evaporator and condenser. The tubes are arranged so as to maximize the heat exchanging ability. It is also designed so that the refrigerant can be spread evenly on all tubes for the sake of surge prevention and the COP decrease in part load operation. Efficiency increasing purpose sub cooler is adopted for the subcool of the condensed refrigerant.

A relief valve for an abnormal situation is at the upper part of the heat exchanger.

Body

Refrigerant distributor

Refrigerant outlet

Refrigerant outlet

Relief valve

Waterbox

Tubes

Figure 6. Evaporator

Body

Refrigerant inlet

Relief valve

Waterbox

Baffle

Accumulator

Tubes

Figure 7. Condenser


17

Lubrication system

Bearing

Bearing

Oil pressure transducer

Oil outlet

Oil cooler

Oil inlet

Oil pressure regulator

Oil outlet

Oil filter

Oil inlet

Oil tank

Oil pump & motor

Sight glass

Figure 9. Lubrication cycle

Introduction

The discharged lubricating oil by the oil pump enters the oil filter to get rid of any unnecessary foreign substance.

This oil becomes cooled to the temperature appropriate for operation condition after through the oil cooler, part of it directly enters gear and high speed side bearings, and the remainder directly enters motor shaft bearings. After the process, it will be drained into the oil tank. The above figure shows the lubrication system of single stage compression type.

Lubrication cycle

Lubricating oil is forwarded through the manual oil charge valve to the Lubrication System.

Oil level can be detected through a sight glass on the oil tank. During the operation, the level should be able to be detected at least from one of them.

The temperature of the oil tank is indicated on the control panel and its temperature range is 30~65 °C while operating. What the oil pump does is to transfer the oil from the oil tank to the system and the adequate pressure different would be 1.0 kg/cm

2 that is maintained by the oil pressure controller. The differential pressure can be seen on the control panel pressure gauge display by the differential pressure between oil tank and oil pump.

The oil pump also helps to send the oil to the oil filter. A valve is installed at the oil filter so that no need to drain the whole oil when replacing the filter only.

After the oil is sent to the oil cooler it is cooled by the refrigerant flowing from the condenser. The refrigerant cools the oil at the temperature between 40~60 °C.

A part of the oil flows through the thrust bearing and gear spray, whereas the rest lubricates the motor shaft bearings and the radial bearings. The oil temperature in the oil tank is measured by temperature sensor and displayed.

The timer automatically activates the oil pump for 120~180 seconds to maintain a constant pressure first before starting compressor. After the system has been shut down, 300~600 seconds lubricating is taken place after the compressor is stopped.

18


Oil reclaim system

Oil reclaim system provides the system to reclaim the oil from the heat exchanger and let it come back to the oil tank. Normally, it is reclaimed at the evaporator, and the vane housing. Refrigerant which came back into the oil tank will then be evaporated to the gas and flow through the DEMISTER line which is located at the upper part of the casing, and then it will be sent to the inlet of the compressor. Oil that is contained in the refrigerant is separated by the demister filter.

MAINTENANCE

Most of the lubrication related deficiencies in rotating parts of the chiller are because of the oil itself. If adequate viscosity, pressure and flow are not obtained, lubricating performance will decrease. Impure substances that are present in the oil also are a cause for the deficiencies.

Freon type refrigerant have chemical attraction with the oil. The viscosity changes according to the temperature and pressure of oil. We have designed the chiller with these problems into consideration.

An oil pump run by hermetic electro motor and a heater controlled by the controlling device are installed in the oil tank to prevent the trouble caused by the refrigerant inflow into the oil, decrease of the viscosity, damage of the pump caused by the cavitation (vaporizing of water and formation of bubbles as becoming partially low pressurized when water or flow at high speed) and the oil inflow into the refrigerant by forming. For these reasons the oil tank is maintained at a high temperature.

The reason to start the oil pump for certain while before the startup of the chiller, is to prevent the compressor's initial unsteady operation because the left over oil in bearings or in the oil line may contain significant amount of refrigerant flow in during the stoppage.

After the chiller has been shut down, oil pump will be operated until the compressor is totally stopped since the compressor rotates due to the internal force.

The only action that can be taken to prevent lubrication inferiority caused by blazing of the oil is replacing the oil itself.

Thus when it is time for cooling operation, make sure that you do the oil replacing adequately.


19

Safety devices

For the sake of safe operation and the protection of the chiller, safety devices are ready as the next table.

No. Safety Devices

1

Installation

Location

Chilled Water

Temperature

Low

Chilled water inlet nozzle

2

Evaporator

Pressure Low

(Temperature

Low)

Evaporator shell

Measurement Item Description

Quantity

Chilled water inlet temperature

Vaporizing pressure

(temp.)

Chiller stops operation if the chilled water outlet temperature below 3°C to prevent freezing of the chilled water. Do not change this set value.

If the pressure inside of evaporator reaches below of the following table, then the chiller stops operation. (Based on the design temperature 43

℃)

Standard setting value 1.95kg/cm

2

1

1

3

4

5

6

7

8

9

10

11

12

13

Condenser

Pressure High

(Temperature

High)

Condenser shell

Condensing pressure

(temperature)

If the pressure inside of condenser reaches above of the following table, then the chiller stops operation.(Based on the design temperature 43

℃)

Standard setting value 10.00kg/cm

2

Motor Temperature High

Compressor

Temperature

High

Motor coil

Compressor outlet

Motor coil temperature

Compressor discharge temperature

To prevent the motor of the compressor, temperature sensors were installed on each phase of coil and when the temperature exceeds 90°C, the chiller stops operation.

If the discharging gas temperature of the compressor exceeds over 70°C, the chiller stops operation.

Bearing Temperature High

Oil Differential

Pressure Low

Thrust bearing Bearing temperature

Oil tank, oil pump outlet

Differential pressure of supplied and intake oil pressure

Temperature sensor is installed on the thrust bearing that holds the impeller's thrust. Chiller will stop operation if the temperature exceeds

85°C.

If the differential pressure between the oil pressure supplied to the bearing and the oil pressure in the oil tank is below 1.0 kg/cm

2

, the chiller will stop the operation.

Oil Temperature High

Oil tank

Oil temperature inside of oil tank

The chiller will stop if the oil temperature in the oil tank is above 74°C.

Oil Temperature Low

Chilled Water

Pump Abnormal

Cooling Water

Pump Abnormal

Cooling water header

Current Limiting Function

Moisture Indicator

Oil tank

Chilled water header

Control panel

Refrigerant supply pipe

Oil temperature inside of oil tank

Chilled water head loss

Cooling water head loss

Current

Moisture in the refrigerant

The temperature should be over 30°C as an initial operating condition to enable the chiller to operate.

The chiller will stop if the head loss of the chilled water flow passing through the evaporator tubes decreases so much that the loss head becomes lower than the standard.

The chiller will stop if the head loss of the cooling water flow passing through the condenser tubes decreases so much that the loss head becomes lower than the standard.

It is a controlling function of Motor Amps that can be set freely in the range of 40 ~ 100% to adjust the current load to the motor of compressor.

The moisture indicator changes the color depending on the amount of moisture in the refrigerant. When there is no moisture it will be green, but if not it will be yellow. It is the time to change into a new filter if you can see the yellow color.

1

3

1

1

1

1

1

1

1

1

1

20


No.

Item

Installation

Location

Measurement Item Description

14

15

Relief Valve

Vane Full Close

Interlock

Evaporator & condenser shell

Vane motor

Relief valves

To prevent the accident by unexpected fire, and so on which can cause pressure increase in the chiller, the relief valve will be operated and exhaust the refrigerant into the air if the pressure exceeds more than the standard.

If the chiller is used in a closed environment, please install a pipe that starts from the relief valve to the outer air.

Operability of temperature sensors

To minimize the starting current, it is a function to enable the compressor to operate only after full close of the guide vane installed at the inlet of the impeller.

Quantity

1

1

16

Temperature

Sensor Abnormal

6 locations including chilled water nozzle

Each temperature sensor

It alarms when temperature sensor is not connected or due to the sensor’s own flaw.

1

17

Pressure Sensor Abnormal

4 locations including Evaporator shell

Each pressure sensor

It alarms when pressure sensor is not connected or due to the sensor’s own flaw.

1

18 Overload relay Control panel Current

If overload is imposed on compressor motor or oil pump motor, it stops the motor.

1

19

Hot Gas Bypass Valve

Evaporator shell, Condenser shell

Guide vane / hot gas valve opening

It prevents frequent start ups at low load, and hot gas bypass valve opens proportionally when vane becomes 30% or lower.

At this time, hot refrigerant gas of condenser goes to evaporator and makes certain chiller load to prevent surge and to prevent frequent startup stop of the chiller.

1

Table 3. Safety devices


21


4-1. Components of control panel and main parts

Controller

HMI with 7 inch Color LCD display is composed of graphical interface.

There are lamp keys for run/stop, vane and oil pump, compressor, oil pump, oil heater operation and cooling/chilled water flow.

There is “Function Key” at the bottom of the screen that changes the features according to the current screen to be able to access to the selected sub menu.

Function key

Front view of the controller Rear view of the controller

Internal diagram of the controller

Configuration part of KEY & LED

Fig 10. Controller

22


Master board and slave board are identical in hardware. It can be either master or slave by the set of DIP switch.

(SW4 OFF: Master, ON: Slave). For the user’s convenience, digital input/output connected via RS232, RS485 communication connections is available along with the analogue input/output.

Power module

Power module

Power

Filter

Commu

-nication

Power Input

Commu

-nication

Figure 11. Internal diagram of master/slave board


23

Controller system diagram

Master, slave, HMI, Relay board communicates via RS485. On either one of master or slave board have analog input

(temperature 12 channel, current 10 channel), analog output (current 4 channel), digital input (20 channel), and digital output (16 channel).

Relay board controls guide vane and diffuser vane.

KEY-

PAD

LCD

DISPLAY

(7inch)

UART

(MAIN)

DATA

DOWN

RS485

UART

(DISPLAY)

UART

(BMS)

UART

(Slave)

MICOM

RS4

85

HMI: screen display and communication

DC 0~5V

INPUT

DIGITAL

OUTPUT

MICOM

UART

(Master)

RELAY: Controls guide vane and diffuser vane

UART

(DISPLAY)

UART

(BMS)

UART

(Slave)

MASTER: Controls temperature, pressure and digital input/output

MICOM

RS485

SLAVE: Controls temperature, pressure and digital input/output

PT100

INPUT

4-20mA

INPUT

4-20mA

OUTPUT

DIGITAL

INPUT

DIGITAL

OUTPUT

PT100

INPUT

4-20mA

INPUT

4-20mA

OUTPUT

DIGITAL

INPUT

DIGITAL

OUTPUT

KEY-PAD

LCD

DISPLAY

(7inch)

UART

(MAIN)

DATA

DOWN

RS485

UART

(DISPLAY)

UART

(BMS)

UART

(Slave)

MICOM

MICOM

(ARM)

RS4

85

MASTER: Controls temperature, pressure and digital input/output

RS485

HMI: screen display and communication

DC 0~5V

INPUT

DIGITAL

OUTPUT

UART

(Master)

RELAY: Controls guide vane and diffuser vane

UART

(DISPLAY)

UART

(BMS)

UART

(Slave)

MICOM

SLAVE: Controls temperature, pressure and digital input/output

Fig 12. Controller block diagram

PT100

INPUT

4-20mA

INPUT

4-20mA

OUTPUT

DIGITAL

INPUT

DIGITAL

OUTPUT

PT100

INPUT

4-20mA

INPUT

4-20mA

OUTPUT

DIGITAL

INPUT

DIGITAL

OUTPUT

24


Other control parts

① Breaker

② Relay

③ Magnetic

④ Contactor

⑤ Thermal relay

⑥ Buzzer

⑦ Terminal strip

⑧ Transformer

⑨ Noise filter

⑩ Fuse

⑪ Relay board

⑫ Master board

⑧ Transformer ⑨ Noise filter ⑩ Fuse ⑪ Relay board ⑫ Master board

① Breaker

② Relay

③ Magnetic

④ Contactor

⑤ Thermal relay

⑥ Buzzer

⑦ Terminal strip

Fig 13 Control system. h The above configuration may be changed for the sake of the improvement of design, product or user convenience.

Thus, please refer to the approved drawings for details.


25

Optional parts related controller

BACnet converter

The controllers from LG basically support Modbus communication protocol.

If the higher level communication protocol is BACnet, you need to apply a separate BACnet converter for protocol conversion.

Communication converter is installed inside the control panel.

Please refer to the following table for the meaning and description of each lamp.

Fig 14. Converter

LED name

TX485

RX485

TX232

RX232

RUN

ETX

ERX

ELK

Condition

Flashing

Off

Flashing

Off

Flashing every second

Maintaining On/Off

Description

Normal data communication with MICOM

Error, Check communication line

Normal data communication with BACnet

Error, check communication line

Board finished Power-on test, and in normal operating

Error, Press the reset button or turn off power & reboot.

LED on at Ethernet Line

ELK is always on when LAN cable is connected. ERX flashes on data reception. ETX flashes on data transmission.

Table 4. Lamps on the converter

26


4-2. Components of starter panel and main parts

Starter panel

It is the electric panel for start-up of compressor motor of centrifugal chiller and the motor protection. It has the protective functions for the current short-circuit and over load.

During the motor start-up, it decreases the current for motor start-up by decreasing electricity consumption of the electric facility. Starter panel has various configurations according to start-up type, high/low voltage power, options, etc. Thus, refer to the drawing supplied together with the product for the configuration of the starter panel.

Power fuse PT(Potential Transformer)

Vacuum contactor

Reactor

(starter)

Motor protection relay

Fig 15. 6600V reactor start-up type h The above configuration may change for the sake of design enhancement, model type, or user convenience. Thus, please refer to the approved drawing for details.


27

4-3. Basic control algorithm

Unique P(proportional), I(integral), and D(differential) algorithms applied to chilled water temperature control, and compared to the existing method, it enabled optimal control by minimizing time to approach the target value, remaining deviation, Under-shoot and Over-shoot during initial start-up and automatic/manual conversion of vane operation.

Over-shoot

LG’s New Control

Algorithm

General Control

Algorithm

Under-shoot

Fig 16. Control algorithm

• Soft loading

- Approach to the control target value with Soft start-up

- Solved unnecessary stops due to rapid guide vane opening during start-up

• Advanced control

- Advanced high class control algorithm development for high precision compared to the existing PID control method

- Prevention of Temperature Cycling due to Overshoot/Undershoot during the conversion from manual to automatic mode

- Intensive safety control by executing preventive control before chiller reaching abnormal stop point, minimize unnecessary stops of the chiller.

28


4-4. BMS support function

Centrifugal chiller’s basic communication protocol is Modbus protocol, and it can be compatible with high level communication methods.

Communication protocol support

• Communication method

- Basic: RS-485, Ethernet(option)

• Protocol

- Basic: MODBUS

- Option: BACnet, TCP/IP

Protocol Converter

Converter 1set can connect up to 8 machines

Fig 17. Detail diagram of BMS


29

4-5. Control Screen (Product function)

Controller Menu Configuration

• User setting

User setting Refrigerant level setting System Information (Output) Account management

Running Mode setting

Control Mode setting

ECO Refrigerant level setting

ECO Refrigerant level P

Chilled water outlet temperature

Ice Making outlet temperature

ECO Refrigerant level I

Chilled water temperature P

ECO Refrigerant level dead band

ECO Refrigerant level valve initial value

Chilled water temperature I

Chilled water temperature D

CON Refrigerant level setting

Automatic Operation temperature (set value +)

Automatic Stopping temperature (set value -)

CON Refrigerant level P

CON Refrigerant level I

CON Refrigerant level dead band

Antifreeze Operation function

Antifreeze Operation temperature

CON Refrigerant level valve initial value

Motor Current limit

Guide Vane Upper Limit

Hot gas setting (Guide vane %)

Hot gas upper limit setting

Hot gas lower limit setting

Cooling water inlet temperature

Cooling water temperature P

Cooling water temperature I

Cooling water temperature D

Dual Mode setting

Lead/Lag Conversion Method selection

Lead/Lag Conversion Time selection

LAG Start-up Load (current %)

LAG Start-up Delay time

LAG Stop Load (current %)

LAG Stop Delay time

Scheduled operation setting

Scheduled Operation Pattern setting (Run)

Scheduled Operation Pattern setting (Stop)

Scheduled Operation Pattern setting (Temperature)

Scheduled Operation Pattern setting (Current)

Manual operation

Vane opening

Diffuser opening

Hot gas opening

ECO valve manual

CON valve manual

System Information (Input)

Ice Making mode selection

Remote Run/Stop signal

Refrigerant temperature low contact

Condenser Pressure high contact

Chilled water Flow normal contact

Cooling water Flow normal contact

Chilled water Pump interlock

Cooling water Pump interlock

Key Lock

Input 10

Bearing temperature high contact

Motor Winding temperature high contact

Oil Pump Overload contact

Vane Closing contact

Compressor Motor Power Normal

Compressor Start-up check

Ice Making mode selection

Remote Selection display

Chilled water Pump operation

Cooling water Pump operation

Cooling Tower Fan 1 operation




Hot Gas Valve

Inverter

Oil Heater Run

Oil Pump Run

Buzzer

Operation Status display

Warning Status display

Display of Abnormal Status

Compressor Operation Status

Evaporator temperature

Condenser temperature

Evaporator pressure

Condenser pressure

Chilled water flow normal contact

Cooling water flow

Remote temperature setting *

Vane Opening

Diffuser Opening

Hot Gas Valve AO *

VFD AO *

Motor Bearing temperature *

System Information (Timer)

Chilled water Pump Stop Delay Timer

Cooling water Pump Start-up Delay Timer

Heat Recovery temperature

Compressor Discharge temperature

Oil temperature

Bearing temperature *

Cooling water Pump Stop Delay Timer

Flow Chattering Ignore Timer

Motor Winding temperature (R) *

Motor Winding temperature (S) *

VGD control Delay Timer

Oil Circulation timer before Run

Oil Circulation timer after Stop

Oil Pressure Check Timer

Vane Close Timer at Start-up

Vane Close Timer at Stop

Vane Open Delay timer

Compressor Start-up Check Timer

Anti-Recycle Timer

Management No. 1

Management No. 2

Management No. 3

System Setting Password

Operation Remaining time

Chilled water inlet temperature.

Chilled water outlet temperature

Cooling water inlet temperature

Cooling water outlet temperature

Motor Winding temperature (T) *

Oil Tank Pressure *

Oil Pump Pressure

Current

Voltage *

Power *

Guide Vane AO *

Diffuser Vane AO *

Vibration sensor *

Compressor discharge temperature 2

System Information

Input Status check

Output Status check

Timer Check

Operation data saving period

Starter Abnormal

Diffuser Manual

Diffuser Manual close

Diffuser Manual open

Oil temperature 2

Bearing temperature 2

Motor Winding temperature (R) 2 *

Motor Winding temperature (S) 2 *

Motor Winding temperature (T) 2*

Communication ID (machine number)

Baud rate

Language

Temperature unit selection

Pressure Unit selection

Flow Unit selection

LCD brightness control

Oil Tank Pressure 2 *

Oil Pump Pressure 2

Current 2

Voltage 2 *

Power 2 *

Guide Vane AO 2 *

Diffuser Vane AO 2 *

Relay 1

Relay 2

30


• User setting

Control Information Setting Abnormal Condition Setting

Ice Making mode

Control Calculation Period

Control temperature Dead band

Chilled water temperature Lower Limit

Oil Differential Pressure Lower Limit

Oil temperature High

Compressor Discharge temperature High

Oil temperature Low Limit at Start-up

Oil Heater on temperature

Oil Heater off temperature

Restart after Power failure

Bearing temperature High

Motor winding temperature High

Evaporator Refrigerant temperature Low

Motor rated Current

Motor rated voltage

Evaporator Pressure Low

Condenser Pressure High

Model Selection

Motor Voltage Lower Limit

Vibration Upper Limit

Operation Time Limit

Guide Vane Control Dead band

Safety control setting

Diffuser Vane Control Dead band

VFD Calculation Period

Cooling Tower PID Calculation Period

Refrigerant Valve Usage Setting

Soft Loading Output Period

Soft Loading Valve Output

Soft Stop Vane Opening

ECO Refrigerant Valve Calculation Period

CON Refrigerant Valve Calculation Period

Refrigerant Valve Control Dead band

Bearing temperature High Prevention

Motor Winding temperature High Prevention

Motor Voltage Low Prevention

Compressor Discharge temperature High Prevention

Timer Setting

Evaporator Refrigerant temperature Low Prevention

Chilled water Pump Stop Delay Timer

Cooling water Pump Start-up Delay Timer

Cooling water Pump Stop Delay Timer

Flow Chattering Ignore Timer

VGD Control Delay Timer

Oil Circulation timer before Run

Oil Circulation Timer after stop

Oil Pressure Check Timer

Vane Close Timer at Start-up

Evaporator Pressure Low Prevention

Condenser Pressure High Prevention

Surge Pressure High Level Setting

Surge Pressure Low Level Setting

Surge temperature High Level Setting

Surge temperature low level Setting

Surge Detection Current Change Amount

Surge Occurrence Detection Time

Surge Occurrence Detection Count

Vane Close Timer at Stop

Vane Open Delay Timer

Compressor Start-up Check Timer

Anti-Recycle Timer

Vibration Upper Limit Prevention

Liquid Intake Prevention Excessiveness

Sensor correction

Chilled water Inlet temperature

Chilled water Outlet temperature

Cooling water Inlet temperature

Cooling water Outlet temperature

Evaporator temperature

Condenser temperature

Evaporator pressure

Condenser Pressure

Chilled water Flow

Cooling water Flow

Remote temperature Setting

Compressor Discharge temperature

Oil temperature

Bearing temperature

Motor Winding temperature (R)

Motor Winding temperature (S)

Motor Winding temperature (T)

Oil Tank Pressure

Oil Pump Pressure

Current

Voltage

Power

Compressor Discharge temperature 2

Oil temperature 2

Bearing temperature 2

Motor Winding temperature (R) 2

Motor Winding temperature (S) 2

Motor Winding temperature (T) 2

Oil Tank pressure 2

Oil Pump pressure 2

Current 2

Voltage 2

Power 2

Sensor set

Evaporator Pressure Sensor

Condenser Pressure Sensor

Chilled water Flow

Cooling water Flow

Remote temperature Setting Signal

Hot gas Valve

VFD

Oil Tank Pressure Sensor

Oil Pump Pressure Sensor

Current Sensor

Voltage Sensor

Power Sensor

Guide Vane AO

Diffuser Vane AO

Diffuser Opening

Option Setting Mode

Guide Vane Min.

Guide Vane Max.

Guide Vane AD value

Minimum Value Setting / Maximum Value Setting

Diffuser Vane Minimum

Diffuser Vane Maximum

Diffuser Vane AD Value


Oil Tank Pressure Sensor 2

Oil Pump Pressure Sensor 2

Current Sensor 2

Voltage Sensor 2

Power Sensor 2

Guide Vane AO 2

Diffuser Vane AO 2

ECO Valve Manual

CON Valve Manual

Offset Setting Mode

Guide Vane Minimum

Guide Vane Maximum

Guide Vane AD Value


Diffuser Vane minimum

Diffuser Vane maximum

Diffuser Vane AD value



31

Controller Menu Configuration

Controlling menu and the names of control panel part

Two Stage centrifugal chiller control device display has the basic screen that can check the current operation status, main menu for user to conveniently use two Stage centrifugal chiller such as user setting, problem/caution information, etc., and system menu for sensor setting, system related setting.

7” Color wide LCD

Start/stop key

Status display lamp

Menu operation key

Alarm lamp Yellow

Guide vane operation key

Oil pump operation key

Fig 18. Front side of controller

!

CAUTION

Do not operate controller with sharp object.

It may cause controller damage.

32


Names of control part

Name

LCD screen

Menu Control Key

Guide vane manual control key

Description

It is the LCD screen displaying the operation information and the status of the chiller in text (Korean, English and Chinese) or graphical animation.

These are keys are for selecting the menu on the screen such as selection of submenu and operation conditions.

The functions keys shown at the bottom of the LCD screen changes depending on the selected screen.

It opens and closes the guide vane manually.

Manual control of the guide vane is possible only when the Vane Manual indication light is on.

Open/Close key- operates only while pressed.

It is to run and stop the oil pump manually.

Oil Pump Manual Control Key

Manual control is possible only when the Oil Pump Manual lamp is on. To enable the manual control, it has to be pushed for approximately 1.5seconds.

Alarm Lamp

It is activated on the condition of abnormality or cautious status.

If this is activated, an alarm message explaining the status is displayed on the message line. When alarm is activated, Cancel key is also displayed with buzzer sound.

If the Cancel key is pressed, the buzzer sound will stop as the Cancel key disappears. And If the cause of the abnormality is taken care of, the message will also be disappeared.

Run/Stop key

It is the key to run and stop the chiller.

To activate this button, it must be pressed for more than 1.5 seconds. During the chiller operation “Run” lamp is on, and when stopped “Stop” lamp on.

Status Indicating Lamp

These display the status of operation of the chiller and the devices attached on the chiller such as oil pump, oil heater and the flow condition of chilled & cooling water.

Table 5. Names of operation part

Names of Color LCD screen display part

ڸ Selected operation method display

ڹ Selected chiller type display

ڼ Displayed categories


33

ں Selected operation mode display

ڻ Current time & menu

ڼ Displayed items

ڽ Message display

ھ Key menu bar

Fig 19. LED screen diagram

① Selected operation method display

There are Local, Schedule and Remote modes selecting how to operate the chiller. That is, Local is to operate the chiller at the local place where the chiller is, Schedule to operate on the scheduled time and Remote to operate in a remote place. It indicates the current operation mode on the screen.

② Selected chiller type display

Chiller type can be selected among R134a 2 stage, R134 and R123.

(When one is selected, it automatically resets the main board, and changes to the selected chiller type mode.)

③ Selected operation mode display

There is only a cooling mode for the air-conditioning chillers. Thus only Cooling mode will be displayed. If it is the chiller for low temperature, it will display Cooling and Icing according to the setting. (Refer to the user setting of main menu and control mode)

④ Current time display

It displays the current year, month, day, day of week, hour, and minute information.

⑤ Displayed items

It displays current operation temperatures, pressures and other current status information of the parts with sensors.

⑥ Key menu bar

It displays the functions of menu control keys.

⑦ Message Display

It displays Run/Stop, operation condition, problem/caution, etc.

34


Basic Screen

It is the screen displaying input values and calculated output status value of each sensor attached to the main body of the chiller. When power on the controller, it is displayed as default screen initially.

1) Main

• It shows animation screen and related DATA of the entire chiller.

- Route :

Fig 20. Main screen

2) Evaporator

• It shows animation screen and related DATA of the evaporator.

- Route :

Fig 21. Screen of Evaporator

3) Condenser

• It shows animation screen and related DATA of the condenser.

- Route :


35

Figure 22. Screen of Condenser

4) Compressor

• It shows animation screen and related DATA of the compressor.

- Route :

Figure 23. Screen of Compressor

36


5) History

• It shows operation information, operation history and error history DATA.

- Route :

6) Menu

• It shows the menu screen.

- Route :

Figure 24. Screen of Operation History

Figure 25. Menu screen


37

Screen Display Item List

4: Items

No.

1

2

3

4

5

6

7

8

No.

Chilled Water Inlet Temperature

Chilled Water Outlet Temperature

Cooling Water Inlet Temperature

Cooling Water Outlet Temperature

Compressor Discharge Temperature

Oil Tank Temperature

Compressor Bearing Temperature

Motor Winding R phase Temperature

Display Range

-40.0~140.0 °C

-40.0~140.0 °C

-40.0~140.0 °C

-40.0~140.0 °C

-40.0~140.0 °C

-40.0~140.0 °C

-40.0~140.0 °C

-40.0~140.0 °C

9 Motor Winding S phase temperature -40.0~140.0 °C

10 Motor Winding T phase temperature -40.0~140.0 °C

11

12

13

14

Evaporator Pressure

Condenser Pressure

Oil Tank Pressure

Oil Pump Pressure

760~0 mmHgA

0.00~20.00kg/cm

2

-1.00~5.00kg/cm

2

0.00~20.00kg/cm

2

0.00~20.00kg/cm

2

-1.00~5.00kg/cm

2

0.00~20.00kg/cm

2

R134a high pressure

4

4

4

4

4

4

4

4

4

4

15

16

17

20

21

Current

Voltage

Power

18 Cooling water flow amount

19 Chilled water flow amount

Vane opening pressure

Cooling water outlet setting

0~1999A

0~9999V

0~9999KW

0~3000 m

3

0~3000 m

0~100 %

3

3~30.0 °C

/h

/h

4

4

4

4

4

4

4

22

Evaporator Refrigerant

Temperature

-18.9~27.6 °C

-26.1~57.2 °C

23

24

25

Condenser Refrigerant

Temperature

Oil pressure difference

Hot gas valve output

-17.8~61.8 °C

-26.1~57.2 °C

-5.00~5.00kg/cm

2

0~100 %

4

4

26

29

30

Cooling tower fan inverter frequency

Automatic stop setting

Actual temp. set value

0~60 Hz

27 PID calculation output 0~100 %

28 Automatic operation setting Calculated value

Calculated value

3.0~50.0 °C

4

4

4

4

4 h Note

1. R134a is high pressure/ standard and R123 is low pressure/ option.

2. Displayed as "TEMPERATURE-MOTOR BEARING" For Low Pressure Use)

3. Can display a decimal point if the current sensor range is lower than 200A.

4. For Ice Making -10.0~50.0°C (for low temperature)

4

4

4

4

R123 low pressure

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

Table 6. Screen Display Items List

Remarks

Note 1.

Note 2.

Optional

Optional

When low pressure is used

When high pressure is used






Note 3.

Optional

Optional

Optional

Low pressure

High pressure

Low pressure

High pressure

Optional

Optional

Note 4.

38


7) Main menu

• Main menu mainly has user setting and system setting as in the following figure.

- Users can set user set, dual set, schedule set and system information.

- Login management, sensor correction, control information setting, abnormal condition setting, safety control setting, timer setting, VGD/VFD setting and sensor setting, can only be set by system manager with password input.

• Menu screen

- Route :

1 2

Figure 26. Input status check screen

When a menu selected using

① button, it moves to the sub menu.

When 'Select' at

② button pressed, it moves to the MENU page. When 'End' button pressed, it returns to the default BASIC screen.


39

- Descriptions of Main menu

Displayed items

USER SET

Usage

It is the menu for users to set values required for chiller operation such as control target temperature, PID value, etc.

DUAL MODE SET It is the menu to set categories used in Dual Compressor

SCHEDULE RUN SET

System information

SYSTEM INFORMATION

It is the menu to set time for chiller to automatically start/stop at the designated time and the temperature for each time period.

Menu to check overall system information such as I/O, timer operation, version, current time, operation information saving period, communication address, communication speed, language setting, model selection, etc.

It is the menu to check overall system information such as I/O status, timer operation, version, current time, operation information saving period, communication address, baud rate, language, machine type, etc.

LOGIN MANAGEMENT It is the menu to change password and management number.

SENSOR CORRECTION It is the Menu to set the most basic information in the chiller operation

SAFETY CONTROL SET

It is the menu to set categories related to safety control to prevent abnormal stops during operation.

ABNORMAL CONDITON SET It is the menu to set abnormal stop conditions of the chiller.

TIMER SET

VGD/VFD SET

SENSOR SET

It is the menu to set abnormal stop conditions of the chiller.

It is the menu to set the relationship between vane opening and diffuser opening rate.

It is the menu to set 4~20mA sensor setting, vane and diffuser.

Table 7. Main menu categories

40


User setting

• Operation mode setting screen has the menu of Local, Timer and Remote mode selecting running type, and has modes of Icing or Cooling selecting operation purpose. Provided that, “operation mode selection” menu is displayed only when Icing mode is set.

- Route :

Figure 27. User setting menu

1. In the above user setting menu screen, select arrow keys to move and select desired category.

2. During the selection, you can use “increase” and “decrease” button to change the set value. (Same as the Password setting” method)


41

1) RUN MODE SET

- Local: To run and stop the chiller at the local site where the chiller is using Run/Stop key on the control panel.

- Remote : To run and stop the chiller at a remote place like site office or automatic control panel using remote

Run/Stop signal(no voltage contact signal or position relay contact signal)

- Scheduled: To run automatically run and stop the chiller on the basis of the scheduled time by the setting of the scheduled operation. Refer to 44p. Timer operation setting.

2) Control Mode selection

This menu can be used when it is installed in a chiller manufactured for ice thermal storage that can perform ice making operation. This menu is displayed when ice making mode is selected in the system function setting. If ice making mode is not selected, this menu will be disabled.

- COOL: It is the standard chiller running mode cooling at the 7~12°C.

- ICING: It is the low temperature type chiller running mode icing at -5~0°C.

3) Other settings

It is a menu to set functions and default values needed for the chiller operation.

Move to the category where to set by pressing MENU selection bar and SELECT key for selection. Then the

MENU are changed to arrows (previous, next, down and up) by which you can move to the item to set on flashing cursor.

Move to the digit by Previous and Next key, change the value by Up and Down key, and press SELECT key will set the value.

4) Setting display screen

RUN MODE SET

Cooling W. Temp D

Item

CONTROL MODE SET

Chilled W. Outlet Temp

Iced W. Outlet Temp

Chilled W. Temp P

Chilled W. Temp I

Chilled W. Temp D

Auto Run Temp (Set Temp+)

Auto STOP Temp (Set Temp-)

Anti-freeze Use

Anti-freeze Temp

Motor Current Limit

Guide Vane Upper Limit

HOTGAS VALVE (GUIDE VANE %)

HOTGAS UPPER LIMIT SET

HOTGAS LOWER LIMIT SET

Cooling W. Inlet Temp.

Cooling W. Temp P

Cooling W. Temp I

Boundary of setting

LOC/SCH/REM

COOL/ICE

3.0 °C~30.0 °C

-20 °C~30 °C

1 °C~10 °C

0~3600 sec.

0~360 sec.

0.0 °C~10.0 °C

0.0 °C~10.0 °C

Used / Unused

0.0 °C~10.0 °C

1~100%

1~100%

0~100%

0~100%

0~100%

10.0~50.0 °C

1.0 °C~10.0 °C

0~3600 sec.

0~360 sec.

Default Value Setting Unit Time to set

LOC.

Always

COOL

7.0°C

-5°C

2.0°C

200 sec.

2 sec.

2.0°C

2.0°C

0.1

0.1

0.1

1

1

0.1

0.1

Always(*)

Always

Always

Always

Always

Always

Always

Always

Unused

3.0°C

100%

100%

30%

100%

0%

32.0°C

4.0°C

0 sec.,

0 sec.

0.1

1

1

1

0.1

0.1

0.1

0.1

1

1

Always

Always

Always(**)

Always(**)

Always(**)

Always

Always

Always

Always

Always

Always

(*): This mark means the item is displayed and applied only for icing (low temperature use) chiller.

(**): This mark means the item is displayed and operated only when hot gas valve is installed.

Table 8. Table of User Setting Items

42


5) PID Temperature Control

Unique P(proportional), I(integral), and D(differential) algorithms applied in controlling chilled water temperature.

Comparing to the existing method, it has optimized in control by minimizing time to approach the target value, remaining deviation and Under-shoot and Over-shoot during the initial start-up and automatic/manual conversion of vane operation.

Approach to the target value softly

Control amount

Target value

Control amount

Target value

<Existing control method> <LS new P.I.D control>

Figure 28. Comparison of the control methods

(1) Chilled water outlet temperature

It is the Menu to set chilled water outlet P.I.D control temperature during cooling operation.

It is the set temperature that becomes the control target value in the PID control calculation.

If timer operation is set, this category is not displayed.

(2) Chilled water temperature proportional band value (CHILLED MODE-P)

It sets the proportional control range of P value which is used to control PID of the chilled water temperature during cooling operation.

(3) Chilled water temperature integral value (CHILLED MODE-I)

It sets the integral control range of I value which is used to control PID of the chilled water temperature during cooling operation.

(4) Chilled water temperature derivative value (CHILLED MODE-D)

It sets the derivative control range of D value which is used to control PID of the chilled water temperature during cooling operation.

(5)Chilled water outlet temp. – Icing

It is the Menu to set outlet control temperature in icing mode.

(6) Cooling tower fan step control

It is the operation method provided for cooling tower fan control for stable cooling water inlet temperature control. Standard type provides 1 cooling tower fan connected to the chiller control panel for start/stop, and up to 4 cooling tower fans can be connected and used. (2 or more connections is option)

!

CAUTION

Set after checking the specification of the cooling tower fan motor maker.

If cooling tower is connected to the controller, check and set the possible number of operations per day and time possible for reactivation of the cooling tower fan motor.

If it is not set correctly, operation may stop due to damage and overheating of the cooling tower fan motor.

If the setting of main menu/system menu/safety control setting/cooling tower control selection becomes ‘step’, the cooling tower fan control operates in step control.

(1) Cooling tower fan operation

It sets the operation temperature of the cooling tower fan during cooling operation.

If the cooling water inlet temperature goes above the set value, all cooling tower fans will start operation.

(2) Cooling tower fan stop

It sets the temperature that stops the cooling tower fans during cooling operation.

If the cooling water inlet temperature goes below the set value, all cooling tower fans will stop.


43

7) Cooling tower fan inverter control

It is the control method to supply stable cooling water inlet temperature, and it is applied when inverter is used for cooling tower fan motor control. The main menu/system menu/safety control setting/cooling tower control setting of the controller shall be inverter.

- It can be used when inverter is attached to user MCC (MOTER CONTROL CENTER) panel.

It is an option and it can be applied after consulting with LG.

- The control output of the cooling tower fan can be one of 4-20mA, 0-5 Vdc or 0-10Vdc.

(1) Cooling water temperature P value

If inverter is used to control cooling water inlet temperature, it sets the proportional section P of the PID control.

(2) Cooling water temperature I value

If inverter is used to control cooling water inlet temperature, it sets the integral section I of the PID control.

(3) Cooling water temperature D value

If inverter is used to control cooling water inlet temperature, it sets the differential section D of the PID control.

(4) Cooling water inlet temperature

It sets the cooling water inlet temperature that becomes the standard for cooling tower fan inverter control.

8) It is to set motor current control operation to protect motor from overload.

The current limit operation is carried out as follows, and temperature control is not carried out during current limit operation. Provided that, if PID calculation value during current limit is smaller than the vane opening of current limit, it performs closing operation according to the PID calculation value.

- Current limit operation

For example, if rated current is 518A, and current limit is set to 80%, then as in the following Fig, at position

①, where current is 80% of the rated current, vane opening stops, and when the current reaches point

②, where current is 105% of the current limit set value, it closes vane until the current drops to point

①.

If the current becomes lower than point

①, it starts the normal temperature control again

Rated current

Current limit set value

Current control operation

Vane open

518

A

80% (518×0.8 A

Ƒ 414)

100% 105%

Vane closed

ڸ

ڹ

(414A) (414×1.05 A

Ƒ 435 A)

Fig 29. Current limit detail diagram

9) Guide vane upper limit

It is the function to protect motor from overload or to artificially limit load of chiller.

It limits the opening of guide vane not to be over set value.

10) Hot gas setting (vane %)

It is the item to set when hot gas bypass valve is applied. It reads the opening guide feedback signal of the guide vane, and hot gas bypass valve performs opening operation from when the opening became the set value during the guide vane closing operation. If this value is set to 30%, hot gas bypass valve performs opening operation when main guide vane opening becomes 30%, and hot gas bypass valve is open 100%(hot gas upper limit setting) when guide vane opening is 0%.

11) Hot gas upper limit setting

It is the item to set when hot gas bypass valve is applied. It sets the upper limit value of hot gas bypass valve opening, and it limits the opening up to the set value. If this value is set to 50%, hot gas bypass valve will not open above that value.

44


12) Hot gas lower limit setting

It is the item to set when hot gas bypass valve is applied.

It sets the lower limit value of hot gas bypass valve opening, and it limits the closing down to the set value.

If this value is set to 5%, hot gas bypass valve will not close below that value.

Main guide vane opening ratio (%)

30%

Hot gas valve operating point

Hot gas valve opening ratio (%)

10%

Opening operation stop

5%

Control signal

Opening operation start

Control signal

Fig 30. Hot gas valve application diagram

DUAL MODE SET

• It is the setting menu to interface when dual compressors are used.

The usage is same as ‘P40. User setting’.

- Route :


45

Fig 31. Dual operation setting screen

Schedule operation setting

• The usage is the same as ‘P40. User setting’.

- Route :

Fig 32. Schedule operation setting screen

46


Please refer to the example for the setting.

Fig 33. Schedule operation setting example screen

Example)

① You can set 8 patterns for scheduled operating. (Setting value of start/stop time, temperature and current)

② Pattern applications are classified to total of 5 types.

③ Select the day for scheduled operation in the calendar screen, and select one from the “5 types”.

▶ Explanation for setting scheduled operation

① 2009. 8. 1: 06:00 RUN / 09:00 STOP, 09:00 RUN/ 12:00 STOP

② 2009. 8. 9: 06:00 RUN / 09:00 STOP, 09:00 RUN/ 12:00 STOP, 12:00 RUN/ 15:00 STOP, 15:00 RUN/ 18:00 STOP

You can set run/stop time, day, and control temperature with each step.

Confirm whether the current day and time are correct at the System Information page.


47

SYSTEM INFORMATION

- Route :

Fig 34. System information

It is the screen displaying the version of the program (Master, Slave and Display) applied to the controller. The “software version number” displayed in the figure is to be displayed for management, and it is useful when an error occurred in the controller.

1) Year, month, day, day of week, hour, minute, second

It is the place to set date and time.

It becomes the standard for saved time information, problem/caution occurrence time and scheduled operation time.

It is the time that becomes the standard for controller operation. Thus, please check if there is any deviation with the current time and correct if so.

2) Operation data saving cycle

It sets the cycle for saving the operation data.

Operation data are all of the values of sensor measurements displayed on the basic screen, and operation data are saved periodically at the time set during the chiller operation.

Provided that, an error related information is saved immediately in the controller memory as soon as it occurs regardless of the saving period.

3) LCD brightness control

It is the menu to adjust LCD brightness.

You can control brightness of LCD by pressing up and down buttons. Up to brighten screen and down to darken.

Pressing ‘End’ key will end the LCD brightness control.

4) Baud rate setting

It sets the baud rate at one of 9600bps, 19200bps, and 38400bps.

48


5) Input status display

• Digital input ports indicate the status as ON (closed circuit) and OFF (open circuit).

It is the menu is to check the status of the input signal contact connected to the control panel of the chiller.

During the digital input check inspection, make sure to check the control circuit diagram to prevent other signal input to the controller input connector. If the connections are mixed with other signal lines, the controller PCB may get damaged.

- Route :

Fig 35. Input status check screen

① Move to the screen of main/evaporator/condenser/compressor

② Input status -> output status -> timer status screen movement button

Displayed Items

Ice Mode Indicating

Remote Run

Refrig. Temp Low

Cond. High Pressure

Chilled W. Flow

Cond. W. Flow

Chilled W. Pump Interlock

Cond. W. Pump Interlock

Bearing Temp High

Motor Winding Temp High

Oil Pump Overload

Vane Closed

Main Power Normal

Comp. Moto Run Complete

Starter Abnormal

Diffuser Manual

Diffuser Manual Close

Diffuser Manual Open

Purge Press Switch

Status Contact operation status

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

If ice making mode selected: Close

If running signal input: Close

Refrigerant Temperature low: Close

If high pressure is detected: Close

If flow rate normal: Close

If flow rate normal: Close

If pump running: Close

ON/OFF If pump running: Close

ON/OFF If high temperature is contacted: Close

ON/OFF If high temperature is contacted: Close

ON/OFF If overloaded: Close

ON/OFF

ON/OFF

ON/OFF

If vane closed: Close

If power is supplied : Close

If compressor is on operation: Close

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

If abnormality detected: Close

If manual stop : Close

If manual close : Close

If manual open: Close

If pressure increased: Close

Table 9. Digital input display items

Remarks

Optional

2Stage

2Stage

2Stage

R123


49

6) Output status check

• It displays the ON (=close) and OFF (=open) status of digital output port along with the analog output status. This menu displays the output status by internal calculation in the controller, and it is composed to be able to check the output result of the controller calculation. If the actual output status is different from the menu, you have to check the status of controller I/O board and its wiring.

- Route :

Fig 36. Output status check screen

① Move to main/ evaporator /condenser/compressor screen.

② Input status -> output status -> timer status movement button.

Displayed items

Ice Mode Status

Remote Mode Status

Chilled W. Pump Run

Cond. W. Pump Run

Cooling Fan 1 Run

Cooling Fan 2 Run

Cooling Fan 3 Run

Cooling Fan 4 Run

Hot Gas bypass

VFD

Oil Heater Run

Oil Pump Run

Buzzer

Run Status

Warning Status

Abnormal Status

Comp. Motor Run Status

Guide Vane

Diffuser Vane

Status

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

0~100%

0~60Hz

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

ON/OFF

0~100%

0~100%

Contact operation status

If ice mode selected: Close

If remote run selected: Close

If chilled water pump on: Closed

If cooling water pump on: Closed

If cooling tower Fan 1 on: Closed

If cooling tower Fan 2 on: Closed

If cooling tower Fan 3 on: Close

If cooling tower Fan 4 on: Close

If oil heater on: Close

If oil pump on: Close

If abnormality detected: Close

If operation switch pressed: Close

If caution is alarmed: Close

If abnormality is detected: Close

If compressor on operation: Closed

Table 10. Output display categories

Remarks

For customer

For customer

For customer

For customer

For customer

For customer

For customer

50


7) Timer status check

• It displays the operation status of various timers calculated in the controller.

This menu is designed for easier view of the operation status.

In this menu, you cannot set the timer.

- Route :

Fig 37. Timer status screen

① Move to main/evaporator/condenser/compressor screen

Displayed Item

Chilled W. Pump Stop

Cond. W. Pump Run

Cond. W. Pump Stop

Flow Chattering

VGD Control Delay

Oil Pump Run

Oil Pump Stop

Oil Pressure Check

Start Vane Close

Stop Vane Close

Vane Open Delay

Comp. Motor Run Check

Anti-Recycle Timer

Display range

0~1800

0~60

0~1800

0~60

1~3600

0~600

0~600

0~60

0~600

0~600

0~60

0~60

Table 11. Timer display categories

Initial value(standard setting)

300 sec.

5 sec.

30 sec.

2 sec.

1800 sec.

180 sec.

300 sec.

10 sec.

120 sec.

120 sec.

30 sec.

20 sec.


51

Sensor Correction

• Each sensor value can be calibrated. The correction set boundary is -5~5°C for temperature, -2kg/cm

2

~2kg/cm

2 pressure, -50m

3

/h~50m

3

/h for flow amount, -200~200A/V/KW for current, voltage, and power.

for

- Route :

Figure 38. Sensor screen

52


Control information setting

• This is the place to set values related to safety control of the chiller. Move to the category where to set by pressing

MENU selection bar and SELECT key for selection. Then key MENU are changed to arrows (Previous, Next, Down and Up) by which you can move to the item to set on flashing cursor. Then move to the digit by Previous and Next key, change the value by Up and Down key, and press SELECT key will set the value.

Usage is the same as ‘P40 User setting’.

- Route :

Fig 39. Control information screen

Abnormal Condition Setting

• This is the place to set the values related to abnormal stop of the chiller. Move to the category where to set by pressing MENU selection bar and SELECT key for selection. Then the key MENU are changed to arrows (previous, next, down and up) by which you can move to the item to set on flashing cursor. Move to the digit by Previous and

Next key, change the value by Up and Down key, and press SELECT key will set the value.

- Route :

Fig 40. Abnormal Condition screen


53

1) Chilled Water Temperature Low Limit

It sets the lower limit value to prevent freezing of the chilled water.

If the chilled water outlet temperature is lower than the set value of ‘chilled water outlet temperature lower limit’, chiller will abnormally stop.

2) Oil Differential Pressure Low Limit

It sets the lower limit of the oil differential pressure.

If the oil differential pressure during the chiller operation becomes lower than the set value, chiller will abnormally stop.

3) Oil Temperature High Limit

It sets the upper limit of the oil temperature

If the chiller oil temperature is higher than the set value, chiller will abnormally stop.

4) Compressor Discharge Temperature High Limit

It sets the upper limit of the compressor discharge temperature

If the compressor discharge temperature during the chiller operation becomes bigger than the set value, chiller will abnormally stop.

5) Bearing Temperature High Limit

It sets the upper limit of the bearing temperature

If the bearing temperature goes above the set value, chiller will abnormally stop.

6) Motor Winding Temperature High Limit

It is the menu to set upper limit temperature of motor winding.

If any one of the motor winding R, S, or T phase temperature exceeds the set value, it will stop the chiller alarming

Abnormal.

7) Evaporator Refrigerant Temperature Low Limit

It is the place to set the lower limit of the evaporator temperature.

If the evaporator temperature during the chiller operation becomes lower than the set value, chiller will abnormally stop.

8) Evaporator Pressure Low Limit

It sets the lower limit of the evaporator pressure.

If the evaporator pressure during the chiller operation becomes lower than the set value, chiller will abnormally stop.

9) Condenser Pressure High

It sets the upper limit of the condenser pressure.

If the condenser pressure during the chiller operation becomes higher than the set value, chiller will abnormally stop.

10) Motor Low Voltage Limit

It is the menu to set the rated voltage of the compressor motor.

Based on this value, motor voltage lower limit control will be performed.

54


Safety control setting

• It is the place to set the values related to the safety control of the chiller. Move to the category where to set by pressing key MENU selection bar and SELECT key for selection. Then the MENU are changed to arrows (previous, next, down and up) by which you can move to the item to set on flashing cursor. Move to the digit by Previous and


- Route :

Usage is the same as ‘P40. User setting’.

Fig 41. Safety control setting screen

12

13

14

15

8

9

10

11

16

17

6

7

4

5

No.

1

2

3

Setting Item

Softloading Output Period

Softloading Output

Softstop Vane Openrate

Bearing Temp High

Motor temp High

Voltage Low

Comp. High

Eva. Temp Low

Eva. Pressure Low

Cond. Pressure High

Surge High Pressure Set

Surge Low Pressure Set

Surge High Temp Set

Surge Low Temp Set

Surge Current %

Surge Monitoring Time

Surge Occuring Count

Setting Range

5.0~60.0

0.0~5.0

0~100

50~100

50~100

50~100

50~100

50~100

50~100

95%

95%

50~100 95%

0.70~12.00 12.00kg/cm

2

0.00~10.00

7.00kg/cm

2

1~100

Initial Value / Unit

1~100

Table 12. Safety control setting categories

10.0 sec.

1.0 sec.

10%

95%

95%

95%

95%

25%

12 times

Note1. For the chiller with R134a (High Voltage) the above devices are standard applied.

For the chiller with R22(Low Voltage) optional

Remarks

Note 1.

Option

Note 1.

Option

Note 1.

Note 1.

Note 1.

Note 1.

Note 1.

Note 1.

Note 1.


55

Timer setting

• It is the place to set the values related to timer required for chiller operation. Move to the category where to set by pressing MENU selection bar and SELECT key for selection. Then the MENU are changed to arrows (previous, next, down and up) by which you can move to the item to set on flashing cursor. Move to the digit by Previous and


- Route :


6

7

4

5

No.

1

2

3

10

11

8

9

12

Setting Item

Chilled W. Pump Stop

Cond. W. Pump Run

Cond. W. Pump Stop

Flow Chattering ignore

Oil Pump Run

Oil Pump Stop

Oil Pressure Check

Start Vane Close

Stop Vane Close

Vane Open Delay

Comp. Motor Run Check

Anti-Recycle

Figure 42. Timer setting screen

Setting Range

1~1800

1~60

1~1800

1~60

30~600

30~600

1~60

30~600

30~600

0~600

10~60

10~3600

Table 13. Timer setting

Initial Value/Unit

300 sec.

5 sec.

30 sec.

2 sec.

180 sec.

300 sec.

10 sec.

120 sec.

120 sec.

30 sec.

20 sec.

1800 sec.

56


VGD/VFD setting

• It is the screen to set the relationship between guide vane and diffuser vane, and to set the control point when VFD is used. For diffuser vane, since it is only applied to R134a two stage centrifugal chiller, so you don’t have to set it for other models.

- Route :


Figure 43. VGD/VFD setting screen

Category

VFD Inverter Frequency 1




VFD Pressure

ΔP 1

VFD Pressure

ΔP 2

VFD Pressure

ΔP 3

VFD Pressure

ΔP 4

VFD Temp

ΔT 1

VFD Temp

ΔT 2

VFD Temp

ΔT 3

VFD Temp

ΔT 4

Inverter calculation period

Setting Range

40Hz~60Hz

40Hz~60Hz

40Hz~60Hz

40Hz~60Hz

2.0~10.0Kg/cm

2

2.0~10.0Kg/cm

2

2.0~10.0Kg/cm

2

2.0~10.0Kg/cm

2

0.0~20.0 °C

0.0~20.0 °C

0.0~20.0 °C

0.0~20.0 °C

1-100 sec.

Initial value

41.1Hz

50.7Hz

57.2Hz

60.0Hz

2.1Kg/cm

2

3.5Kg/cm

2

4.9Kg/cm

2

6.1Kg/cm

2

0.5 °C

2.2 °C

3.6 °C

5.0 °C

60

Table 14. VGD/VFD setting categories

Set value

40.0Hz

45.0Hz

51.0Hz

60.0Hz

2.1Kg/cm

2

2.5Kg/cm

2

4.1Kg/cm

2

6.8Kg/cm

2

1.3 °C

2.8 °C

3.7 °C

5.0 °C

60

Remarks

Inverter Frequency 4-

20mA output

Condenser-Evaporator

Pressure

Chilled water inlet - Set temperature


57

- VFD control operation

ΔP= Evaporator pressure – condenser pressure

6.8Kg/cm 2

60Hz

2.1Kg/cm 2

40.0Hz

0.5°C 5.0°C

ΔT= Chilled water inlet temp. – Chilled water outlet temp. set value

Figure 44. VFD control detail diagram

Sensor set

• It is the menu to set each pressure sensor and current sensor, etc., and you have to set precisely, and it is only effective for the sensors set for use. After changing AD value of the guide vane and diffuser vane to min./max. by manual operation, change Reserved to ON, and finish the setting by selecting the corresponding setting(min. value setting, max. value setting).

- Route :


Figure 45. Sensor setting screen

58


LOGDATA

• It is the menu to check operation data, temperature control graph, start/stop information, etc. stored in the controller of the chiller. You can also check the information of the total accumulated number of operations (number of start/stop) and total accumulated operation time of the chiller and main subsidiary devices.

- Route :

1) Run Information

- Route :

Figure 46. Chiller history screen

1 1

1

1

Fig 47. Chiller operation information screen

You can check up to 1~300 data using

① button.

2) Run Data

- Route :

Fig 48. Operation history information screen

3) Error Data

- Route :

1

1

1

1

1

11

1

Fig 49. Error history information screen

You can check up to 1~300 data using

① button.

You can select error history help using

② button.

1


59

60


4) Help Feature

• It displays the help message about the errors and cautions. If Help key is pressed on the error and caution screen, the help message for the corresponding message is displayed on the help screen. Previous key will show the help message of the previous numbered and Next key for the next numbered help message.

- Route :

5) Print

- Route :

Fig 50. Help function screen

Fig 51. Print function screen

- User set print: It prints the user set page.

- System set print: It prints the current system set information.

- Run information print: It prints from start to end page for run information. (1~300 EA.)

• Auto print: Print with regular time interval.

• Print mode: “1”– All data, “2”– only unit (used by start-up)

- Run data print: It prints from start to end page for run data. (1~300 EA.)

- Error log Print: It prints from start to end page for error data. (1~300 EA.)

6) Graph

- Route :

1

1

Fig 52. Data graph screen

Use

①buttons to move and select the corresponding data graph display category.

Activated data will be displayed as reversed at

②.


61

62


Manual operation screen

Fig 53. Manual operation screen

Vane

It is to open and close thee vane (guide vane) manually from the menu. It is composed to be operated as the same as the control valve automatic/manual conversion key and open/close key on the front of the display device. When it is stopped, forced closing is operated by control logic, so manual open does not work.

Oil pump

It is to operate the oil pump manually from the menu. It is composed to be operated as the same as the oil pump automatic/manual conversion key and start/stop key on the front of the display device. Manual stop does not work to protect chiller during the operation.

Remote control signal and the connection

Remote Run/Stop signal connection

• No voltage and continuous contact (2 wire connection)

Chiller control panel

101

DIC1

Operation signal

Chiller status

ON

OFF

RUN

Stop

User control panel

RUN

Fig 54. Remote control signal detail diagram h Min. Run/Stop pulse maintaining time: maintains for at least 2 sec.


63

64


Manual operation screen

Signal name

Chilled water pump interlock

Cooling water pump interlock

Chilled water pump Run/Stop

Cooling water pump Run/Stop

Cooling tower

Fan Run/Stop

Signal type

Input

(No voltage contact)

Output

(No voltage contact )

Signal type Caution

It is the interlock to confirm whether the pump motor starter is ‘ON’.

If the input signal does not exist during starting, the chiller will not start.

If the input signal does not exist during running, it will sense as abnormal state and warn.

It outputs DC24V to detect the status of the contact.

Make sure to have no contact resistance over 100 Ω.

(Do not handle the electric wire pipe together with other power lines.)

It is the Run/Stop signal of the pump or fan.

Connect it when it is operated by interfacing start/stop signal from chiller.

Use it within AC250V 0.1A (resistance load).

Refer to final manual 69P.

Table 15. Manual operation screen detail diagram

Central monitor panel and connecting signals

Signal name

Contact for motor start-up checking signal

Signal type

Output


Contact for

Run/Stop indicator

Output


Meaning of the signal

ON when start signal is input

OFF when stop signal is input

ON when chiller operation

OFF when chiller is stopped

Contact indicating

Chiller FAULT

Caution

Output


ON when there is a problem in the chiller

Use it within AC250V 0.1A

(resistance load).

Indicate chiller at

REMOTE run mode

Output


ON when remote operation mode is selected

Chiller WARNING

Output


ON when alarm breaks

Table 16. Central monitoring panel and connection signal detail diagram


65

Check list before inspection

1) Thorough preparation

Check first aid method, arrangements around the work site, and safety of the facility and machine.

2) Review with circuit diagram

If power system receives power from another source, check the powers to the panels, power application to the

1st side of the circuit breaker and proper grounding.

3) Contact

Check if you can closely contact with the relevant departments.

4) Check for no voltage state and safety measures

During the inspection of the main circuit, please review the following issues for safety.

- Open the related breaker and disconnecting switch and make no voltage on the main circuit.

- Check no voltage status with electroscope, and make groundings where necessary.

- Open circuit breakers and disconnect switches and attach a warning sign board "Checking".

- Use the disconnection switch operation after power is disconnected.

- Especially when the power is supplied via another source such as consumer side power distribution panel, automatic control, MCC panel, etc., take the above c) and d) actions to the other side switches.

5) Cautions for current and voltage

Discharge the remaining charges and conduct grounding before you inspect the condenser and cable connection part.

6) Prevention from wrong operation

Disconnect the power and attach a caution mark.

7) Prepare insulated protection equipment

Wear safety protection equipment such as insulated gloves, safety helmet, insulated boots, and safety apparel fit for the rated voltage.

8) Measures against rat, insects, etc.

Take countermeasures to prevent rat, insects, snakes, etc from entering into the panel.

66


List to check after maintenance

1) Final check

- Check whether any staff is inside the panel.

- Check whether the removal of the temporary building for inspection is being delayed.

- Make sure not to forget bolt tightening work.

- Check if any tools are left.

- Check whether rat or insects have been in.

2) Recording of the inspections

When inspection, make sure to record the summary of the inspections and repairs, status of the failure and date, etc. to utilize them as the reference for the next inspection.

!

CAUTION

Establish the daily inspections to be able to check the load of the machine in operation, operation time, operation environment, etc.

The inspection period stated in this manual is a general inspection period. Therefore establish the inspection plan according to the load status of the machine and usage frequency.

Do not test the insulation resistance on the 2nd side of the transformer for controller or control power.

Do not test the insulation resistance on the parts like sensor, switch, etc. which are connected to the controller.


67

General Inspection items

Inspection

Inspection categories

All

Inspection items

Ambient environment

Is there any dust?

Is the ambient temperature and humidity adequate?

Is there any abnormal vibration?

Equipment Is there any vibration or noise?

Input voltage

Is the main circuit voltage normal?

Is the main circuit voltage normal?

Insulation resistance test

Disconnect all power before testing insulation resistance.

Insulation between the transformer 1st side and grounding bus-bar.

When measuring the resistance, disassemble all grounding wires connected to grounding bus– bar.

Overheating Is there any trace of overheating in each component?

Fixed parts Is there any missing fixed parts?

Conductor/wire

Is there any contamination of conductor?

Is there any damage in the wires?

Main circuit

/ Control circuit

Terminal

Relay

/contactor

Is there any damaged part?

Is there any oscillation during operation?

Is there any damage on the connector?

Space heater

Is there any color change of the heater component in starter panel?

Daily 1 year 2 years

Criteria

Refer to Chapter 1. Environmental conditions

No abnormality

Refer to Chapter 1. Environment

*Low voltage (600Vac or less) DC 500V class mega, it shall be 5M

Ω or more.

*High voltage (exceeding

600Vac, 7000Vac)

DC 1000V class mega, it shall be 30M

Ω or more.

No abnormality

No abnormality

No abnormality

No abnormality

No abnormality

No abnormality

Sensor & switch

Is there any disconnection or short circuit?

Is there any damage in the contact part?

Grounding

Is there any rust on the connection part?

Is there any damage in the grounding conductor?

Is there any noise in the grounding system?

Note: Grounding resistance shall meet the requirements of the related codes and standards.

Phase advance capacitor

Is the expansion under the limit?

Cooling fan Is there any abnormal noise? (Control Panel)

Control function

Safety function

Is the safety function in normal operation?

Is the start-up sequence normally carried out?

Is the stop sequence normally carried out?

Is the temp. regulation within the specification?

Analog value

Is the displayed value correct?

Display

Indication

Lamp

Is the indication lamp displayed with the normal brightness?

No abnormality

No abnormality

No abnormality

No abnormality

Normal control

No abnormality

No abnormality

Table 16. General Inspection Items

68


4-6. Startup and Control sequence

Signal Flowchart

Signal flowchart of the centrifugal chiller

Run/Stop

Chiller

Run/Stop

Run/stop signal

STOP

Chilled water pump on

RUN

Comp. Stop

(2M signal

OPEN)

No

Timer > 5sec*

Yes

Cooling water pump on

AND Condition

Oil temp. > 30°C*

Vane close S/W ON

Cooling Water Temperature > (Set Value + 2°C)*

Restarting prevention timer OFF

Check Flow amount

Yes

Oil circulation timer > 3 min*

Yes

Starting Condition

(Satisfaction)

Yes

No

Timer=0 for oil circulation pump before start-up

No

No

Standby until satisfaction

Yes

Stop Condition

(Satisfaction)

OR Condition

Vane opening < 10%

Vane Close S/W ON

Vane Stop Timer > 240sec*

Comp. Stop (CR OFF)

AND

Cooling water Pump Stop

Yes

Timer > 30sec*

Yes

Chilled Water Pump Stop

Oil Timer > 5min*

Yes

Oil Pump Stop

CR (Closing Relay) ON

Yes

Comp. Run Complete signal (2M)

(within 20sec*)

Yes

Chiller RUN

(Operation/Safety Control)

No

Abnormal

Figure 55. Signal flowchart

Chiller Stop

Yes

Yes


69

Run Button

Run Lamp

Start lamp

Chilled water pump

Run/Stop


Interlock

Chilled water differential pressure switch

Cooling water pump

Run/Stop


Interlock

Cooling water differential pressure switch

Oil pump start/stop

Check chilled water pump interlock Alarm

Check chilled water flow Alarm

Check cooling water pump interlock Alarm

Check cooling water flow Alarm

Check chilled water pump interlock Error

Check chilled water flow Error

Check cooling water pump Interlock Error

Check cooling water flow Error

Check Oil differential pressure

Check Vane closed switch Alarm

Check Alarm for low temp. of oil for start-up

Message display of Soft start-up operation and Safety control operation conversion

Abnormal Signal for start-up completion(2M)

Compressor Run/Stop

Signal for start-up completion(2M)

Message

Cooling

W.

Pump

Start

Timer

1.5 sec 5 sec

Timer for oil pressure check

Timer for start-up oil circulation pump

10 sec 180 sec

Timer for compressor start-up check

20 sec

Timer for

Vane open delay

Anti-

Recycle

Timer

60 sec 1800 sec

RUN

Hour

Figure 56. Timing Sequence

70


Stop button

Stop button

Stop lamp


Run/Stop


Interlock



Run/Stop


Interlock


Oil pump start/stop

Compressor start/stop

Signal for start-up completion(2M)

Message

The first operation among vane closing switch, soft stop setting or Vane closing timer

Vane close timer when stopped

Cooling water pump stop timer

Timer to stop chilled water pump oil circulation

1.5 sec 120 sec 30 sec 300 sec

STOP

Figure 57. Timing Sequence

Hour


71

4-7. Product protection function

Protection Logic

Classification

Content Cause Operation

Sensor

Temperature, pressure and current sensors abnormality

Detected abnormality from temperature, pressure or current sensors

Chiller stops

Chilled water pump interlock Error

Detected Error with pump interlock during operation

Chiller stops

Interlock

Cooling water Pump Interlock Error

Detected Pump interlock problem was detected during operation

Chiller stops

Chilled water low-flow abnormal

Cooling water Flow Low Error

Detected Flow interlock problem was detected during operation

Detected Flow interlock problem was detected during operation

Chiller stops

Chiller stops

Control of High temperature of Oil

Error

Detected High temperature of Oil Chiller stops

Error of Condenser Pressure High

Error

Detected Condenser Pressure High Chiller stops

Evaporator Low Pressure Error Detected Evaporator Pressure Low Chiller stops

Temperature and pressure

Evaporator Refrigerant Prevention

Error

Compressor discharge Temperature High error

Detected Evaporator Refrigerant

Temperature Low Error

Detected Compressor discharge temperature High Error

Surge occurred

Compressor Surge current Error

Voltage


Error

Chilled water temperature Low error

Detected Motor winding temperature High Error

Chiller stops

Bearing high temperature problem

Detected Bearing high Temperature Error

Detected chilled water outlet temperature Low error

Chiller stops

Chiller stops

Detected Low Voltage Error

Detected Compressor Surge current Error

Chiller stops

Chiller stops

Chiller stops

Detected Compressor motor Voltage Low Error

Chiller stops

Condition

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

72


Classification

Content

Starting prevention when Oil temperature Low

Cause

Oil temperature setting value

≤ starting oil low

Operation

Oil low temperature prevention control caution message displayed caution message displayed

Condition

Caution

Prevention of Low voltage

Prevention of Condenser Pressure

High

Prevent evaporator low-pressure

If compressor motor voltage is below the low voltage prevention set value - (100- set value)/2, close the guide vanes

Display warning message to prevent control of Low Voltage

If the condenser pressure is above the Prevention of High pressure set value + (100- set value)/2, the guide vane is closed.

If the Evaporator pressure is below the low pressure prevention set value- (100- set value)/2, close the guide vanes.

Display warning message to prevent control of Condenser

Pressure High

Display warning message to prevent control of Evaporator low pressure

Prevention

Control

Evaporator Refrigerant Low temperature

Prevention

If the Evaporator temperature is below the low temperature prevention set value- (100-set value)/2, close the guide vanes.

Prevention of Compressor discharge temperature high

Display warning message of

Evaporator Refrigerant temperature Low Prevention control

If compressor discharge temperature is above the high temperature prevention set value + (100-setting value)/2, the guide vanes is closed.

Display warning message to prevent control of compressor discharge temperature high

Prevention Bearing temperature High

If bearing temperature goes above the temperature prevention high set value + (100- set value)/2, the guide vanes is closed.

Display message warning to prevent control of Bearing temperature High

Preventive control of chilled water low temperature

If chilled water temperature is below the low temperature prevention set value - (100- set value)/2, close the guide vanes.

Chilled water outlet temperature, low-temperature prevention control caution message is displayed

Compressor surge current prevention

If current changes more than set value during operation and if it occurs (set times /3) times within the set time, the guide vanes is closed.

Preventive control of

Motor over-current

When the compressor Motor Amps reaches the set value*105%, the vane is closed to lower current below set value.

Prevention of Motor winding high temperature

If motor winding temperature is above the high prevention set value

+ (100- set value)/2, close the guide vanes.

Display of warning message to prevent surge current to compressor

Display warning message to prevent control for compressor motor over current

Display warning message to prevent control of high temperature of Motor winding

Caution

Caution

Caution

Caution

Caution

Caution

Caution

Caution

Caution

Caution


73

Classification

Content Cause Operation


Open

Motor winding temperature input contact is Open.

Chiller stops

Evaporator Refrigerant Low temperEvaporator Refrigerant Low temperature Contact Closed ature Contact Closed

Oil pump over-current contact is closed

Thermal over-current contact attached to oil pump power supply is closed

Bearing temperature High contact closed

Bearing temperature, high temperature contact is closed

Chiller stops

Chiller stops

Chiller stops

Switch contacts

Condenser high pressure contact is closed

Condenser high pressure input contact is closed

Chiller stops

Start-up failed

Compressor starting completed. No input signal

Chiller stops

Delta contactor is open in operation

Starter panel contactor is open during operation

Chiller stops

Starter panel abnormal, contact closed

Starter panel abnormal, input contact is closed

Power to Compressor Motor contact open

Compressor power supply contact is open during operation

Chiller stops

Chiller stops

Condition

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Table 17. Protection Logic

74

5. START-UP

5. START-UP

5-1. Delivery and Installation Check

From Receipt, Installation to Startup

Installation of Foundation

(foundation panel)

Receipt and Installation

Air tightness test

Dissatisfaction

Vacuuming test

Oil charging

Charging

Nitrogen gas

If a month or more left until operation,

Charge Refrigerant

Insulation resistance test

Lubrication system operation adjustment

Function test for starter and controller panel

Function test for safety devices

Check before start-up

Check before and after start-up

Wiring construction between starter panel and control panel.

(The order can be changed.)

Run chilled water pump

/Run cooling water pump

5. START-UP

75

Stop

Load operation and operation setting

Record run data

Water quality analysis for cooling and chilled water

Operation guide

Finishing

Fig 58. From receipt to Startup

Selecting a location

• If the chiller has to be installed near heat generating devices, keep distances more than 5 meters from boilers and hot-air blowers, and more than 2 meters from other heat generating devices.

• Choose a well-ventilated place and avoid place with high temperature.

• Choose a place with less humid.

• Provide ample space for service (for control and maintenance of pipes and tubes)

Foundation

• Build the foundation to withstand the concentrated heavy weight of the chiller.

• The foundation should be higher than the surface of the water, and install the drainage around.

• Be sure to install the drain pipe to the drainage hole.

Receipt and Installation

• The chiller should be installed evenly leveled to the ground.

• Install the chiller on a foundation with flat support surfaces, level within ±1mm with the manufacturer-supplied isolation pad assemblies under the unit.

• Make sure the foundation surface is flat and leveled within ±1mm using a level, and if not, readjust it within: ±1mm, using spacers.

76

5. START-UP

5-2. Preparation for start-up

Preparation for start-up

• It is called start-up run that the first run after receipt and installation or the run after long-term stoppage (over 1 month) before the regular operation of the chiller.

• Preparation for start-up is the maintenance and repairing work at least once a year after installation\, which is a very basic and important task.

Air tightness test

Vacuuming test

Oil charge

Refrigerant charge

Insulation resistance test

Lubrication system operation adjustment

Function test of starter and controller panel

Check safety devices

Fig. 59. Preparation procedure for start-up

Checking the leak parts

It is recommended to perform leakage test following the steps in Fig 58.

Refer to the temperature and pressure values of the refrigerant in Table 18.

5. START-UP

77

Leakage Inspection

• The condition that requires the leak test

- After the chiller is disassembled and repaired,

- If the nitrogen's pressure charged in factory was lower during the transportation before the initial start-up:

• Weak Points for leak:

- Parts where the gasket is used

- Nut tighten part, bolt and nut

- Copper tube connecting part

- Sight-glass welded part

- Compressor motor terminal

Inspection method

1) Charge the nitrogen in order until the internal pressure of the machine reaches 2 kg/cm

2

, 5 kg/cm

2

, 9~9.5 kg/cm

2

.

2) Perform the soapy water test on every connecting part.

3) If the inspected pressure lasts for more than 30 min., prepare to do the soapy water test for smaller parts.

4) Mark the leaking point.

5) Eject the inner pressure of the machine.

6) Fix all the leaking points.

7) Do leak test again on the repaired points

8) After performing the large leaking test, increase the inner pressure up to the value of 9~9.5 kg/cm

2

.

9) Do the small leak test and fix them all.

10) After the leak test Is finished, exhaust the nitrogen gas very carefully.

* Please close the valve of evaporator, as when you increase the pressure inside of the chiller, the relief valve on the evaporator may get open.

Note: Open the relief valve on the condenser by1.05 Mpa (10.71 kg/cm

2

).

The relief valve on the evaporator open at 0.99 Mpa (10.1 kg/cm

2

)

78

5. START-UP

1

2

-1

0

-5

-4

-3

-2

5

6

3

4

11

12

13

14

7

8

9

10

Temperature °C Pressure 1kg/cm

2

-26.18

-20

0

0.3255

-19

-18

-17

0.3850

0.4465

0.5101

-12

-11

-10

-9

-16

-15

-14

-13

-8

-7

-6

0.5758

0.6437

0.7138

0.7862

0.8610

0.9381

1.0176

1.0996

1.1841

1.2713

1.3610

1.4535

1.5486

1.6466

1.7474

1.8512

1.9579

2.0675

2.1803

2.2962

2.4153

2.5376

2.6632

2.7922

2.9246

3.0604

3.1998

3.3428

3.4894

3.6397

3.7938

35

36

37

38

31

32

33

34

39

40

41

42

47

48

49

50

43

44

45

46


2

15

16

3.9517

4.1136

17

18

19

4.2793

4.4491

4.6230

24

25

26

27

20

21

22

23

28

29

30

4.6230

4.9932

5.1697

5.3605

5.5558

5.7555

5.9597

6.1685

6.3819

6.6001

6.8231

7.0510

7.2838

7.5216

7.7644

8.0124

8.2657

8.5242

8.788

9.0578

9.3318

9.6128

9.8988

10.190

10.488

10.791

11.101

11.416

11.738

12.066

12.400

71

72

73

74

67

68

69

70

75

76

77

78

83

84

85

86

79

80

81

82


2

51

52

12.740

13.087

53

54

55

13.400

13.800

14.167

60

61

62

63

56

57

58

59

64

65

66

14.540

14.921

15.308

15.703

16.104

16.513

16.929

17.353

17.784

18.223

18.670

19.124

19.587

20.057

20.536

21.023

21.518

22.023

22.535

23.057

23.587

24.127

24.676

25.234

25.802

26.379

26.966

27.563

28.171

28.788

29.417

Table 18. HFC-134a Temperature / Pressure

5. START-UP

79

Vacuum Dry & Vacuum Test

• The vacuum dry work has to be taken to eliminate the humidity when the machine is exposed to the atmospheric air for a long time or it is indicated that the moisture got into the machine or complete pressure loss of refrigerant happened due to refrigerant leak.

!

WARNING

Do not operated the compressor motor or the oil pump motor, and do not take any insulation resistance test when performing the vacuum dry work.

Even instant rotation for rotation check-up can damage the electrical insulation and cause huge damage.

• Generally the vacuum dry work is performed at a room temperature. The higher the room temperature is, the faster the vacuum dry performance will be done. Stronger vacuum quality is required to evaporate the moist in the environment of lower room temperature. The vacuum dry working procedure is as follows.

1) Connect the high capacity vacuum pump (Approximately above 120 LPM) to the refrigerant charge valve.

The length of the pipe from the pump to the machine should be as short as possible and the diameter of the pipe as big as possible for minimum gas flow resistance.

2) To measure the vacuum, if the pressure gauge is installed or pressure value from MICOM is available, the pressure gauge may be used.

3) When vacuuming work, open all the valves except the valves connected to external.

4) Allow approximately 2 hours of additional vacuum pump operation, if the surrounding temperature of the machine is above 15.6 °C, and while the vacuum pump is operated if the manometer is indicating 756mmHg.

If the internal pressure of the chiller is kept below 756 mmHg, the accumulated moist in the machine would be frozen and then this ice is evaporated more slowly than in normal condition, which leads to a delay of the vacuum dry work. If there is hot water at this situation, let the evaporator and the condenser be flowed by the hot water and then operate the vacuum pump.

5) Fasten the vacuum pump valve and stop the pump, and then record the vacuum gauge value.

When reading the degree of the vacuum while the surrounding temperature varies, it has to be compensated by converting the temperature change into pressure using below equation.

△P + (760 + H)x t 2

273+ t

2

t 1

273+ t

1 mmHg

H: Internal pressure before the inspection (mmHg) t1: Surrounding temp. before the inspection (°C) t2: Surrounding temp. after the inspection (°C)

Table 19. HFC-134a Temperature / Pressure

6) The vacuum dry work is terminated if there is no change in the vacuum gauge value after waiting for 4 hours.

The machine is well air-tight if the leak rate is below 0.1 mmHg/h(=0.1 Torr/h). If the vacuum gauge value rose up, repeat step 4) and 5).

7) If the value still changes after several time of vacuum dry work, set the inner machine pressure above

9~9.5kg/cm

2

.G and perform the leak inspection. After fixing the part where it is leaking, redo the vacuum dry work.

80

5. START-UP

Oil charge

1) Generally the chiller is charged with the oil in the compressor when shipping from the manufacturer, but if not, follow the steps as described below.

2) Charge the oil through the charging valve located at the bottom of the oil tank. At this time, make the inner part of the machine vacuum using a vacuum pump. (If the refrigerant charging is proceeded, the charged refrigerant will evaporate and eventually the pressure will rise. Thus, do the oil charging first.) If the inner machine pressure is high, use the pump from the tank for the charging. In this case, the Discharging pressure of the pump shall be more than 14 kg/cm

2

.G when the suction pressure is 0kg/cm

2

.G. The oil charging or removal, however, must be done at the condition that the chiller is totally stopped.

3) The oil level must be charged more than 2/3 of the sight glass. Also if only the oil pressure and the temperature are within the designated range, oil foaming may be happening.

4) Be cautious not to let any air enter into during oil charging.

Refrigerant charge

!

CAUTION

When the refrigerant charging or discharging is performed on a machine that uses springs for isolation at the bottom, fix the springs not to move up and down. The spring moving may stress the connected pipe line.

1) The chiller is charged with nitrogen gas when leaving from the factory. Remove the nitrogen gas at the job-site before doing the refrigerant charging.

2) Operate the chilled and cooling water pump to prevent freezing when performing the refrigerant charging.

3) It is the most preferable to adjust the refrigerant charge amount when the Chiller is operated under the design load. Adjust the amount of refrigerant by the difference between chilled water outlet temperature and evaporation temperature and through the sight glass.

Insulation resistance test

1) Mega test is to apply the direct voltage to the insulation material to obtain insulation resistance by measuring the leaking current through the material.

Insulation resistance =

For 3000 and 6000V class: use mega for 1000V.

For 380 and 440V class: use mega for 500V.

Leak Current

Applied Voltage

2) Keep away any unnecessary personnel during the test for it is using high voltage.

3) Cut all the exterior power that is supplied to the chiller before performing the test. The 3-phase motor that is for above 500hp, can cause danger due to the electric charge when the inspection was performed. Thus, completely discharge it after the inspection and then handle the ground terminal.

5) Do not perform the high voltage mega test in vacuum condition.

6) Electrical insulation resistance drops in accordance with the temperature increases, and is sensitive to the temperature change which means that it varies. The changed temperature can be written in temperature coefficient and the temperature coefficient and applied equation is as follows.

Insulation Resistance in inspecting (°C)

0

5

10

15.6

20

25

30

35

Temperature coefficient

0.4

0.5

0.63

0.81

1.00

1.25

1.58

2.00

Insulation Resistance in inspecting (°C)

40

45

50

55

60

65

70

75

Table 20. Temperature coefficient under insulation temperature

Temperature coefficient

2.50

3.15

3.98

5.00

6.30

7.90

10.00

12.60

5. START-UP

81

7) Other factors that influence the insulation resistance

<Pollution of the outer surface of the insulation body> If absorptive and deliquescent materials like acid, chloride and etc are adhered on the surface of the insulation body, they influence the insulation resistance. Remove the foreign substances before the inspection. <Condensing Point> If the insulation body temperature is below the surrounding temperature's dew point, moisture condensation can be preset on the insulation body surface (especially at the crack and the groove) and influence the insulation resistance. The inspection should be taken into action when the insulation body temperature is above the surrounding temperature's dew point. Record the dry bulb and the wet bulb temperature surrounding air. <Absolute Humidity> Even through the insulation body temperature is above the dew point, the atmospheric vapor influences insulation resistance. Avoid conduction test at the place where the absolute humidity is high present.

8) Apply an electric current for a minute to the spot to be measured up insulation resistance. Read and record the value. Apply the inspection standard when the insulation body temperature is 20 °C. (When measured at a different temperature, use the temperature coefficient and convert the value indicated after a minute.)

9) Taking measures according to insulated condition.

Temp. of insulation body at inspection (°C)

Danger

Bad

Re-inspection

Good

Better

Excellent

Value indicated after a minute

Below 2 M

Ω

Below 50 M

Ω

50~ 100 M

Ω

100~500 M

Ω

500~1000 M

Ω

Above 1000 M

Ω

Action

Repair or Exchange

Troubleshooting

Troubleshooting h Motor that is within the range of "Bad" and "Re-Inspection" at the mega insulation test, must take the POLARIZA-

TION INDEX test.

Table 21. Insulation condition

10) Polarization Index Test

Record the indicated value appeared when performing the mega test after a minute and the one after 10 minutes.

Insulation Inhaling rate = indicated value after 10 minutes indicated value after 1 minute

Condition

Danger

Bad

Re-Inspection

Good

Better

Excellent

Insulation Absorption Rate

Below 1

Below 1,5

1.5~2

2~3

3~4

Above 4

If the motor's insulation absorption rate is within the range of "Danger", must be returned or replaced.

If the motor's insulation absorption rate is above the range of "Bad", must be checked additionally after 4 hours of careful operation.

Table 22. Insulation absorption rate status

11) The following should be recorded when performing the mega test

- Type and voltage of the mega tester

- Connection part of the mega tester

- Surrounding temperature and humidity of the test taking place and the tank's internal pressure in case of hermetic type

- Stoppage period before the inspection

82


Function test for starter and controller panel

• Test before the Start-up

1. Control Panel and Electric lines

Cut the power and check the controlling parts and switches for any foreign substances. Also check for normal operation and terminal connection conditions by handling the switches.

2. Voltage

Check if the voltage indicated at the voltage meter of the starter panel is identical to the rated voltage on the chiller name plate.

3. Chilled and cooling water circulation system

Check if the chilled and cooling water operation is depicted properly on the display by activating individual pump.

• Control Device Operation Test

1. Check the wiring condition

Check whether the wiring of power, sensor, etc. are properly connected.

Special checking should be taken to power line.

2. Check the display condition after control power in

Be more cautious if there is any symptom of getting short for 5 seconds after the power is in.

If problem occurs, immediately cut the power and check for abnormality.

3. Check values displayed on the panel

Check if the display indicating sensor values are normal.

If the sensor indicates abnormal or error message is displayed, check the connection of the sensors.

4. No power operation

While the power of the main motor is cut, operate and check whether the operation is normal up to the Starter panel operation signal. If a message displayed for abnormality, check the part.

• Check of Safety Device

Flow operation test for chilled water and cooling water

- Close the valves located at the pipe of the chilled and cooling water, and check whether the differential pressure switches for flowing are working properly or not.

5. START-UP

83

5-3. Start-up

• After the preparation is done for start-up, proceed as follows.

Preparation for start-up

Power On

Check oil temp.

in the oil tank

Check the vane

Oil pump operation

1) Input power to the control panel and the starter panel, and check the status.

2) Input power to the oil heater 1~2 hours prior to the main operation and make sure that the temperature of the oil inside the tank is 30~65°C.

3) After checking the vane opening as 0%, set the vane's operation to "Auto". The vane is to maintain 0% on any condition of "Auto", "Open", "Stop", "Closed" when the chiller stops.

4) Set the oil pump condition of the control panel to

"Auto".

5) Activate the chilled water pump. When operating, close the outlet valve, open the air ventilation valve and then open the outlet valve to a small carefully to avoid water hammering so that necessary amount of flow passes through. If water keeps coming out after the air discharged through the air outlet, close the air valve.

6) Activate the cooling water pump. Caution required just as step 5).

7) Check the control panel display if it is working properly. Check if the display is showing local operation mode and chiller's possible operation condition.

Auxiliary

Operation

Control Panel

Display Check-up

Figure 60. Start-up procedure

84

5. START-UP

• If the chiller is working under Local Operation Mode, follow the steps as follows. If strange situation is detected, shut down the chiller immediately and follow the "troubleshooting" procedure. For more detailed information, refer to the "Check list".

Press the Operation

Button

Oil Pump Run

Start the compressor motor

Start-up competed

Operating

1) Checking the oil pressure

When the operation button on the control panel is pressed, oil pump will be activated that leads to an increase in the oil pressure and if the differential pressure between supplying oil to the bearing and the inner tank oil lasts for 120~180 sec. over 0.8 kg/cm

2

, the compressor motor will be operated.

2) Direction of the compressor motor's rotation.

3) Starting characteristic

At this time, 2 items check-up is needed simultaneously. Make sure 2 people are working together.

- Direction of the motor's rotation

Record the rotating direction at the counter load part of the motor. If the direction is opposite, stop the chiller and change the two among three phases.

- Starting Characteristic

Check the starting current, acceleration completion time as on the "Check List".

4) Check the Operating Current

5) Motor Cooling Status

- Operating Current

After the start-up is done, the vane will be opened gradually and the current increases simultaneously.

Operation current should not exceed the rated current.

If exceeds, set it referring to the “capacity control module.”

- Motor Cooling Status

Periodic physical check-up of the motor surface temperature is required while operation.

- Checking the oil tank and the bearing temperature

Check if the oil tank and the bearing temperature is preserved at 40~65°C. If not refer to "Trouble Shooting" and "Check List".

6) Checking all sorts of pressure status

7) Checking the operating sound and vibration

8) Chilled-water inlet and outlet temperature

9) Cooling-water inlet and outlet temperature

Fig 61. Start-up procedure (2)

5. START-UP

85

• Load Operation and the Operational Setup

After the Start and the Stoppage operation, perform the Load Operation as follows.

In any cases, let do not exceed the electromotor rated current.

As mentioned already at the "Product Protection Function", it would not be able to be overloaded due to the set of the motor current limiting function, but please double check.

Set the temperature control function according to the load.

Set the user's setting function as mentioned already in the "Product Protection Function".

When performing automatic operation

Set the vane operation mode to auto

1) In case of load increasing

To preserve the chilled water outlet temperature, the guide vane is opened up to the electromotor rated current.

2) When the load is parallel with present performance of the chiller

The guide vane is stopped at a certain degree of opening.

3) In case of load decreasing

- In opposition to 1), to preserve the chilled water temperature the guide vane is close.

- When the load is continuously decreased, the chilled water outlet temperature will be decreased and the chiller will be stopped by the function of "Chiller operation/stoppage". If the chilled water outlet temperature increases to the level of setup temperature, it will be operated automatically.

- The oil pump will perform additional operation even after the chiller's shut down.

The purpose of this action is to preserve the oil pressure (for inertia operation of about 1 min. after the chiller shut down) and to protect the electromotor from frequent start and stoppage.

86

5. START-UP

5-4. Startup procedure after long-period of stoppage

When letting the chiller to be still for a long period of stoppage, the refrigerant must be transferred to a separate refrigerant pot to prevent machine pressure decrease and leak.

Charge approximately 5kg of refrigerant into the machine to prevent air-entrance.

If the installed area of the chiller is frequently a place of below zero, drain the chilled water, cooling water and the condensing water to prevent freezing. Also waterbox drain must be opened.

Leave the oil in the machine and supply heater power to maintain minimum oil tank temperature.

Before operating the centrifugal chiller after long-period of stoppage (longer than 1 month) or instant stoppage (less than a month), follow the next steps.

1. The machine should be checked for unstable part or for abnormality for smooth operation.

2. To prevent refrigerant loss due to leak during the stoppage, following steps must be taken.

1) Compressor (simple inspection over the rotating part)

* Simply check from the appearance of the impeller, bearing and rotating part.

◇ Combination status of the impeller and the shaft

◇ Assemble condition of the Gear

◇ Foreign substance in the gear box

◇ End play of the impeller shaft

◇ Assemble condition of the guide vane

◇ Check the vane and the drive shaft

◇ Check the gap between the impeller and the cover with a thickness gauge

2) Lubrication system

◇ Loosen and crack of the oil pipe

◇ Replacing or clearing the oil filter

◇ Cleaning the oil tank

◇ Replacing the oil

3) Refrigeration System

◇ Check the refrigerant pollution possibility

◇ Clean the ejector

◇ Clean the tube

◇ Water quality analysis

◇ Exchange or clean filter related parts

4) Condenser, Evaporator Preservation (Corrosion countermeasures while stoppage)

During a long term period stoppage, follow the next steps for the corrosion countermeasures due to condenser and evaporator tube corrosion.

- Each tube should be brushed and the scales must be removed completely. Fill it in with clean water. Finally preserve it with rustic proof material in it.

- In principle preserve the chiller without water after complete drain.

- Execute all regular maintenance check-up and the inspection for the operation system with care. Controlling test should be taken before the main operation.

If the compressor oil indicates an abnormal high-level display, there are possibilities that the oil absorbed the refrigerant.

3. Start the machine in accordance with “Start-up” after checking the 1~2 items.

5. START-UP

87

5-5. System Shutdown

• When stopping the product, perform it in the following order.

Press the Stop button

Compressor stop

Oil pump stop

1) The vane is automatically closed when the stop button on the control panel is pressed.

2) Check the compressor motor stoppage time

- Measure the delay time to the compressor's mechanical stop after the chiller's shutdown; the delay time due to motor's inertia moment.

3) Check the oil pump remaining operation

- Check if the oil pump is operating till a resolved time after the chiller's shut down.

4) Checklist after stoppage

- Stop the cooling water pump.

In this case, close the outlet valve of the pump gradually and then stop the cooling water pump.

- Stop the chilled water pump.

Close the outlet valve of the pump gradually and then stop the chilled water pump.

- Record the oil and the refrigerant level after stop.

Stopping completed

Figure 62. Stopping Procedure

88

6. MAINTENANCE

6. MAINTENANCE

6-1. Maintenance criteria

Maintenance and overhaul inspection (repairs)

• Usage Deterioration of Machine

Although there may not be any malfunction or structural deformation of the machine, it generally can be worn or aged after a long time usage. Though a centrifugal chiller which has been operated for a long time is operating, the motor can be declined and abrasion of the rotating section due to the secondary creation caused by oil burning, carbonization and etc. In many cases, such symptoms can normally be detected externally by the vibration and abnormal sounds that are present. In these cases, it is very important to take preventive action prior to the occurrence of accident and maintain a proper working condition for the sake of the machine's longer life.

• Examination and thorough overhaul (Repair)

The trouble ratio of a machine is normally distributed as the following Fig.

Period for Overhaul(repair)

Initial trouble

Stable

Trouble by

Abrasion

Hour

Figure 63. Machine failure rate

<Period of Initial Failure> occurs at the beginning stage of the machine’s operation due to the manufacturing matter from the factory itself.

Then it enters the <Period of Stabilization> that is followed by the <Period of Abrasion> after a certain period of time.

If it enters to the <Period of Abrasion> region, possibility of the machine's failure is going to rise up. Thus, it is very essential to take thorough overhaul (repairing) action will prevent accidents and allow an optimum maintenance.

We recommend on the basis of a long term experience and statistical data that you take the thorough overhaul (repairing) action at the following period.

1) Chiller for commercial cooling : Every 5 years

2) If is an industrial process machine that is working throughout the whole year and requires a high reliance: Annually

• Criteria for Overhaul

Accidents may take place if there are irresistible abrasion and deformation that leap over the assigned limit of the machine’s individual parts.

For instance, if the bearing wears out, the destroyed oil film will cause the metallic contact to happen, which will lead to a high possibility of the bearing burning out.

The impeller itself might be able to have a contact with other parts and be destroyed. If the central distance of the velocity increasing gear leaps over a certain number, teeth of gear could also be destroyed.

Thus LG Electronics sets up (1) Utilization Limit (2) Exchanging Standards and based on these criteria, "Thorough

Overhaul Procedure" was made to maintain the chiller under proper operating condition till next overhaul period, and according to this standard, composing parts can be inspected and replaced.

6. MAINTENANCE

89

• Merits of the Maintenance Contract System

(1) Economic Efficiency

- Deterioration of machine can be minimized by a regular maintenance action.

- As machine life id prolonged, the possibility of huge accident is reduced, which can save maintenance cost.

- As the contact is performed based on yearly predetermined cost, the effective management over the budget of the maintenance cost can be possible.

In order to prevent an unexpected cost caused by a sudden breakdown a counseling service with the customer is provided in advance.

- Opportunity loss of customer's production process resulted from the unexpected stop of machine can be eliminated.

(2) Safeness

- Through checking a lot of safety devices, safe use of the machine without trouble can be possible.

- As a regular inspection is applied before trouble, breakdown is prevented beforehand.

- In case of maintenance contract, as training is provided, operator's management skill over the machine is developed.

(3) Quickness

- As machine status can be always checked through a regular inspection, precise instruction can be given to even a trouble notice by phone call.

- Maintenance Contract machines will get the premium service as the first creditor even during the rush season when there are plenty of service loads.

Maintenance Contract Work Details (Standard)

1. Inspection before the start cooling

(1) Air-tightness Test

(2) Refrigerant charging

(3) Electricity related insulation test

(4) Safety device setting

2. Maintenance during the cooling period (1 time)


(2) Checking the operation Setup

(3) Chiller operation setup

3. After finishing cooling season

(1) Refrigerant full extraction

(2) Nitrogen gas charging & sealing

(3) Filter checking(Replacing)

(4) Cleaning oil tank

(5) Checking the operation record

(6) Checking sensors (Replacing)

(7) Picking Oil

4. Water quality analysis (1 time)

(5) Function test between Starter panel ~ Control panel

(6) Vacuuming


(8) Air tightness test

(9) Electricity-relate insulation test


(11) Checking the oil pump


90

6. MAINTENANCE

• Chiller for Annual Operation

1. Check-up during the Operation period (5 time)


(2) Inspection the operation record


2. Overall Maintenance (once)

(1) Refrigerant full extraction


(3) Filter inspection (Replacing)

(4) Cleaning oil tank

(5) Checking the operation record

(6) Checking sensors (Replacing)

(7) Oil extraction

3. Water quality analysis

(8) Air tightness test



(11) Checking the oil pump


• Standard Maintenance Frequency

(1) Chiller for Cooling only; Cooling Start x 1, During operation x 1, Cooling Completion x 1

(2) Chiller for Annual Operation : During Operation x 5, Overall Maintenance x 1

• Excluded Items

(1) Cleaning the Heat Exchanger

(2) Overhaul(repair)

(3) Items that are not listed in the contract

Overhaul(repair)

• Compressor

1. Compressor Overhaul(repair)

(1) Preparation

(2) Disassemble Compressor

(3) Check capacity controlling device

(4) Inspection over the Compressor parts and cleaning

(5) High-speed gear inspection

2. Auxiliary Work

(1) Air-tightness Test

(2) Vacuum drying


(4) Full extraction of Refrigerant

(5) Refrigerant charging

(6) Extraction of the Oil

(7) Cleaning the Oil tank

(8) Inspect the Filter types

(6) Inspecting Impeller shaft

(7) Assemble Compressor

(8) Check Flow rate

(9) Putting parts

(10) Cleaning


(10) Checking the Oil pump

(11) Inspect and control over the safety device

(12) Starter panel ~ Control panel operating test


(14) Check over the operation record

6. MAINTENANCE

91

• Motor

1. Motor overhaul (repair)

(1) Check Stator coil and rotor

(2) Check the Parts

(3) Measure Shaft Vibration, Concentricity degree

(4) Air gap, End Play measurement

2. Auxiliary works

(1) Refrigerant , Oil pipe Disassemble and Assemble

(5) Gear disassemble and assemble

(6) Electricity wiring disassemble and assemble

(7) Insulation Resistance Measurement

(8) Winding Resistance measurement

• Standard Contract Disassemble Inspection(Repairing) Parts

1. Compressor

(1) Bearing

(2) Shaft labyrinth

(3) Impeller shim (1st level, 2nd level)

(4) O-ring, Gasket

(5) Oil filter

2. Motor

(1) Bearing

(2) Rear cover

(3) O-ring, Gasket

(4) Filter Drier, Moisture Indicator

• Excluded Work from standard

1. Starter panel Disassemble Inspection(repairing)

2. Replacing Motor Coil

3. Cleaning the Heat exchanger

• The Others

1. Compressor

(1) Impeller

(2) Diffuser

(3) Impeller cover

(4) Impeller shaft

(5) Return channel 1, 2, 3

2. Motor

(6) Gear

(7) Plate type Heat exchanger

(8) Capacity adjustment device

(9) Lock nut, bolt

92

6. MAINTENANCE

6-2. Periodic maintenance

Daily inspection

Checks the evaporator and condenser pressure, oil tank pressure, differential oil pressure and discharge oil pressure of the chiller. Compare the values with the ones of the general chillers maintenance table.

- Compressor and motor daily inspection standard

Classification Inspection items

Motor Cooling Condition

Able to see the refrigerant flow

Motor Drain Temp.

Compressor,

Motor

Motor Drain Oil Flow

Compressor discharge gas temp.

Vibration/noise

Inspection method

Check the refrigerant flow via. Moisture Indicator

Criteria


Measure the temperature of the outer surface of the motor using a surface thermometer

Measure the draining pipe's outer surface with the thermometer


Measure using Differential Pressure

Check temp. at the control panel




Check with the hand and Ear

Measure using the vibration measuring instrument if necessary

Noise: Below 85dB

When there's no abnormal vibration below x,y,z: 25μm

* The motor adopts liquid refrigerant cooling system. It supplies the liquid refrigerant by the differential pressure between the condensing and evaporation pressure.

* Check and make sure that the refrigerant liquid supplying line's moisture indicator is showing green.

If the green color is altered to yellow, it means that the moisture quantity has exceeded more than the standard quantity in the machine. Thus, replace the filter dryer.

Fig 64. Compressor and motor daily inspection standard

6. MAINTENANCE

93

- Daily inspection of Condensers

Classification Inspection items Inspection method Criteria

Condenser

Cooling water

Inlet

Outlet

Condensing pressure state

Heat exchanging state

Check at the Panel

Check at the Panel

Below 34 °C

21°C or more

Check at the Panel 5~10 kg/cm

2

Temperature difference between condensing temp. and cooling water outlet temp.

Temperature difference between condensing temp. and cooling water outlet temp.

* If the outlet temperature of the cooling water is below 21°C, condensing pressure would be decreased, which will lead to a lack of differential pressure at the motor cooling and the oil cooler and finally become the situation of insufficient of cooling water.

The main cause of worsening the heat exchange can be seen for the scale attached inside cooling pipe and insufficient cooling water amount.

Fig 65. Condenser daily inspection standard

- Evaporator daily inspection standards

Classification Inspection items Inspection method Criteria

Chilled water

Inlet

Outlet

Check at the Panel

Check at the Panel

Below 5~15°C

Above 3°C

Evaporator

Above 3°C

Heat exchanger condition

Check at the Panel 5~10 kg/cm

2

Temperature Difference between the evaporation temp. and the chilled water outlet temp.

0.5~3°C

Refrigerant charging amount Check through the sight glass

Refrigerant condition Check through the sight glass

When evaporation pressure is decreased, the evaporator tube freezes and eventually damaged, or compressor surge would also be possible. Causes of the decreased evaporating pressure would be insufficient refrigerant quantity, low temperature water and abnormal heat exchanging efficiency. Like the condenser tubes, if foreign substances are in or the scales adhered, corrosion may occur which will lead to a in efficient heat exchanging. This happens to decrease the refrigeration ability or may be the cause for surge.

Fig 66. Evaporator daily inspection standard

94

6. MAINTENANCE

- Daily inspection standard of Compressor and motor. Generally, the failure ratio of a machine is distributed as the shape drawn in the following Fig.

Classification

Oil

Inspection items

Oil amount

Temp.

Differential Pressure

Inspection method

Visual inspection

Check at the Panel

Check at the Panel

Criteria

At least one of two sight glasses should have oil level appearance.

30~60°C

0.8 kg/cm

2

Oil Pressure Vibration

Leakage

Check at the Panel

Visual inspection of the oil system

Check by ear

No Vibration

There shall be no leak

No abnormality Oil pump Noise

Oil pump remaining flow operation

Stop the chiller and check with watch

300 sec.

Figure 67. Compressor and motor machine failure ratio

<Lubrication cycle>

The oil is taken through the manual valve into the tank. The level of the oil can be detected by the one sight glasses on the oil tank. When the compressor is stopped oil should be able to be found through the sight glass.

The temperature of the oil tank is displayed on the panel and while operation, the temperature would be 30~65 °C.

The oil pump transfers the oil from the tank and the pressure at that time would be above 0.8kg/cm

2

.

The oil pump is sending the oil to the oil filter, where a valve is installed so that there is no need to drain the whole system when replacing the filter.

Afterwards the oil is sent to the oil cooler and then cooled by the refrigerant from the condenser.

The refrigerant cools off the oil as low as 30~60°C.

Oil that left the cooler passes through the oil pressure transducer and then to the refrigerant expanding valve’s temperature sensor box, flows to the bearings and gears for lubrication.

The oil temperature is measured at the high-speed thrust bearing and the oil is drained to the oil tank that is located at the lower part of the compressor.

The control device operates the oil to the oil pump prior to the main operation for 120~180 seconds at a constant pressure. At stoppage when the main operation has stopped, it performs a 300 seconds of after lubrication.

Soft start-up opens guide vane slowly during the start-up to prevent foaming of the oil.

If the guide vane opens too quickly, it will let the refrigerant in the oil to be boiled because of the intake pressure's rapid decrease, which will eventually cause foaming. This foaming will lead to dropping the pressure in oil pump, and the low pressure of oil lead finally bad lubrication.

6. MAINTENANCE

95

Monthly inspection

- Compressor and motor monthly inspection standard

Classification Inspection category Inspection method Criteria

Motor insulation Measure at 1000V mega Above 100 M

Ω

Compressor and Motor

Vane operation

Protector insulation

Characteristics of start-up

Visual inspection of the opening status

In Vane Full Close, 0%

Check indication in Vane Full Open, 100%

Check the status of opening indication

Soft movement of Indication Value

500V mega

(Protector ~ Main Coil, Protector

~ ground) Measuring

Mark

● for the corresponding start-up method

1. Direct standing start-up

2. Y-

Δ start-up

3. Kondorfer start-up

4. Reactor start-up

* In case of chilled water outlet temp _°C

Above 3 M

Ω

Time of start-up current flow t:

5~25 sec.

Start-up current: A

Timer set value (sec.)

Fig 68. Compressor and motor monthly inspection standard

• Generally the starting current of the motor is about 600% that of the rated current in direct input. And in case of y-

Δ , it is 200%, for kondorfer 250%, and for Reactor 400%.

• Measuring frequency and record should be at least once a month for daily/monthly inspections. This data can be the clue of solution if problems are occurred to the motor.

- Lubrication system monthly inspection standard

Classification

Oil

Inspection items

Oil charging amount

Oil pump motor insulation

Inspection method Criteria

Check through the sight glass

Refer to the standard charging amount

Check through the sight glass 3M

Ω

Fig 69. Lubrication system monthly inspection standard

96

6. MAINTENANCE

Yearly inspection

- Yearly inspection

Classification

Motor

Condenser

Evaporator

Inspection items

Motor Terminal fasten bolt

Chemical analysis

Tubes condition

Chemical analysis

Tubes condition

Oil cooler cleaning

Ejector cleaning

Oil and lubricant

Filter cleaning

Oil tank cleaning

Oil Replacing

Inspection method Criteria

Check the slackness

Check the loose

Loose terminal finishing state

Water quality analysis

Check it at the operation record or by opening the waterbox.

Water quality standard

No pollution

Water quality analysis

Check it at the operation record or by opening the waterbox.

Water quality standard

No pollution

Clean by refrigerant

Disassemble cleaning

No corrosion or pollution should be present

No abnormality

Filter exchanging, Cleaning the housing

Disassemble cleaning

No abnormality

No pollution

2000 hours or 1 year

Fig 70. Yearly inspection standard

<Water quality analysis>

The cooling water at the open circulation type cooling tower uses the evaporation latent heat to lower down the water temperature and also recycles it.

At this time the water evaporates and the chloride ions in the water and the acid ions will increase. This will lead to enrichment situation and eventually deteriorate the water quality.

Also, in the cooling tower, water and air are always in contact with each other and the contaminating material(automobile exhaust gas, sulfurous acid gas, dust, gas of chemical plants such as ammonia or petroleum gas, etc.) deteriorates the water quality even more.

These pollutant causes can corrode the pipe, scales adhered causes the tubes to have holes and lockouts which are leading to a decreasing effect of heat exchanger.

Therefore, it may end to replacing the tubes, increased power cost, or the chiller failure.

Thus, cooling water quality must be maintained at a certain level.

Water quality analysis should be taken place periodically and if the results are out of the standards boundary(Table

23.), it must be replaced. At the beginning of the season and at the initial starting of the machine, water quality analysis is inevitable.

To prevent the cooling water enrichment, certain amount of cooling water should be drained during the circulation and then supplying fresh cooling water. Another way of water quality analysis would be using chemical handling.

<Tubes State>

If water corroded dirt is adhered or foreign substances are mixed in the tubes, resistance is increased which makes it hard for the chiller to have a good efficiency. It also makes it easy to cause surge.

If sandy like solid materials are mixed in the cooling water, erosion or corrosion may occur at the entrance of the tubes, therefore when cleaning the tubes make sure that you check the inner surface of it.

Install a filter at the inlet of the cooling water pipe. Generally, a cooling tower is used for the cooling water system, but when using the subterranean water or the riparian water it is possible for the scales to be adhered easily due to low quality of water compared to the chilled water.

6. MAINTENANCE

97

Item pH(25°C)

Electric conductivity

(Ma/m)(25°C) (

㎲/cm) (25°C)

Chloride ion (mgCl

￣/L)

Sulfuric ion (mgSO

4

2

￣/L)

Acid consumption (pH4.8)

(mgCaCO

3

/L)

Total hardness (mgCaCO

3

/L)

Calcium hardness (mgCaCO

3

/L)

Ion silica (mgSiO

2

/L)

Iron (mgFe/L)

Copper (mgCu/L)

Sulfide ion (mgSO

2

￣/L)

Ammonium ion (mgNH

Stability index

4

+/L)

Residual chlorine (mgCl/L)

Free carbon dioxide (mgCO

2

/L)

Cooling water system

Circulation type

Once through type

Chilled water system

Circulating water

Supplied water

Once through water

Circulating water

(Below 20°C)

Supplied water

6.5~8.2 6.0~8.0 6.8~8.0

6.8~8.0 6.8~8.0

below 80 below 800 below 30 below 300 below 40 below 400 below 40 below 400 below 30 below 300 below 200 below 50 below 50 below 50 below 50 below 200 below 50 below 50 below 50 below 50 below 100 below 200 below 150 below 50 below 50 below 70 below 50 below 30 below 50 below 70 below 50 below 30 below 50 below 70 below 50 below 30 below 50 below 70 below 50 below 30 below 1.0 below 0.3 below 1.0

below 1.0 below 0.3

below 0.3 below 0.1 below 1.0

below 1.0 below 0.1

Not detected

Not detected

Not detected

Not detected

Not detected below 1.0 below 0.1 below 1.0

below 1.0 below 0.1


below 0.3 below 0.3


below 4.0 below 4.0

5.0~7.0

ㅡ ㅡ ㅡ ㅡ

Trend

Corrosion Scaling

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

ㅇ

Note)

(1) Name and unit of the items are based on KS MD100.

(2) O sign within the table refers to the factor related to the corrosion or scaling trend.

(3) Unit and value within the parenthesis show data based on the previous unit, for reference.

(4) If the temperature is high (40°C or above), generally the corrosion rate becomes high especially for steel that directly contacts water without any protective coating. It is recommended to have an effective plan for the water such as adding anti-corrosive additive or air removal process, etc.

Table 23. Water quality management standard for chilled water/cooling water

# Refrigerant and oil charge amount

Single stage centrifugal chiller

Frame

5

6

3

4

7

Refrigeration capacity

(RT)

250 ~ 400

500 ~ 600

650 ~ 850

900 ~ 1300

1400 ~ 2000

Amount of refrigerant

(kg)

450

550

750

950

2100

Table 24. Refrigerant and oil charging amount for Single Stage centrifugal chiller

Oil quantity

(L)

40

40

60

62

120

98

6. MAINTENANCE

6-3. Maintenance during off-season

(1) If the operation needs to be stopped, to reduce the machine pressure and leak possibility, move the refrigerant to a separate refrigerant container.

(2) To prevent intake of air into the machine, store the machine with about 5kg refrigerant charged or to apply 0.5kg

nitrogen.

(3) If the place where the machine is installed goes below 0°C frequently, to prevent the freezing, drain the cooling water, chilled water and condensed water. Also open the waterbox drain.

(4) Leave the oil charged in the machine, and to maintain the minimum oil tank temperature, supply power to the oil heater.

6. MAINTENANCE

99

6-4. Annual maintenance(1/2)

Inspection items

Motor cooling status

Inspection method

Check refrigerant flow status from moisture indicator

Criteria

Check flow status

Actual measurement

Yes No

Decision

Touch the surface of the motor with hand

10~30 °C

Motor insulation

Start-up characteristics

(mark O in the corresponding start-up method)

Measured at 1000V

Kondorfer, reactor

100MΩ or more

Start-up time

T=5~25 sec.

Start-up current: A

Pass t = sec.

A=

A

Fail

MΩ

Timer set value (sec.)

Timer Kondorfer reactor


T1: start-up timer

T2: subsi

-diary timer

Vane operation

In case of chilled water outlet temp. ( ) °C

Check opening 0~100%

Check opening status

Check timer set value with independent timer operation test after disconnecting high voltage.

Check 0, 100%

Shall operate smoothly

Vane opening

Operation current

Check opening ratio

Check current value

Motor stopped time

Discharge gas temp.

Vibration noise

In normal operation

After chiller is stopped, check from half-load side of the motor when the meter axes stopped time

Measure the surface of the bolts with thermometer

Touch with hand or check with ears

Less than 105% of the rated

10~60 sec.

About 30~90°C

When there is no problem

Pass

Pass

Pass

Fail

Fail

A sec.

°C

Fail

100

6. MAINTENANCE

6-4. Table for Annual maintenance(2/2)

Inspection items Inspection method Criteria


Decision

(OX)

Inlet Check with thermometer

34°C or less

(standard condition)

°C

Cooling water

Outlet

Check with thermometer

24°C or more

(standard condition)

Condensing pressure (temp.)

Check with manometer

(thermometer)

Heat exchanging status

Difference between chilled water outlet temp. and evaporating temp.

6~10 kg/cm 2

(26~42 °C)

Heat exchanging status

Difference between condensing temp. and cooling water outlet temp.


Chilled water

Inlet

Outlet

Evaporating pressure

(temp.)



(thermometer)

1~3 °C

6~15 °C

4°C or more

2~5 kg/cm

2

(0~21 °C)

1~3 °C

Refrigerant charging amount

Boiling status

Check through sight glass

Visual inspection

Refer to 10.5 standard charging amount

Refrigerant contamination

Oil amount

Check through sight glass

Visual inspection

Whether contaminating material, moisture, oil is included

Check with sight glass on the gear box during operation kg/cm kg/cm

Yes

2

2

°C

(°C)

°C

(°C)

°C

No

Pass Fail

Pass Fail

Oil charging amount

Accumulated charging amount after charging new refrigerant

Refer to 10.5 standard charging amount

Month Day

Oil tank temp.

Temp. of Bearing

Oil differential pressure




30~65 °C

50~85 °C

Oil supply pressure –

Oil tank pressure

(0.8 kg/cm

2

or more)

°C

°C

Oil pressure vibration

Oil leakage

Oil pump noise

Oil pump remaining operation

Vibration of the pressure value

Oil system visual inspection

Check with ears

Measure with watch

300 sec.

Yes No

Pass Fail

Pass Fail min.

Vane operation

Manual opening of vane

• Stop at rated current

• Closed at 105%

Pass Fail


Decrease chilled water amount to check the operation


Decrease cooling water amount to check the operation

Pass

Pass

Fail

Fail

Table 25. Table for Annual maintenance

6. MAINTENANCE

101

6-4. Table for Annual maintenance

Operation Inspection Table (A)

Inspection date: Year Month Day

Address

Company

Model

Main motor

Changes

Serial No.

Max. output(KW):

(Tel)

(Staff in charge)

Rated voltage(V):

Rated current(A):

Serial No.

Replaced parts

Conclusion

Person in charge of service:

Note:

1. The manufacturer is not responsible for the problems happened due to the reasons as follows; poor water quality, customer's poor maintenance and natural disaster.

2. Overhaul for the compressor should be done in 5 years or in 10000 hours, whichever comes first.

3. Beware that some items can be changed without prior notice for the product improvement.

Table 26. Operation Inspection table

102

6. MAINTENANCE

6-5. Oil maintenance

Compressor oil replacement

- Checking the Lubrication System

Record the level of the oil on the oil tank sight glass in operation, and check the level when the chiller is stopped. If the level has dropped below the lower part sight glass, it is necessary to check whether the oil recovery system is working properly. If oil is needed, add it through the oil charging valve. To charge the oil opposite from the refrigerant pressure, a pump is needed. The charging quantity of the oil should be referred to LG Electronics and the specification of the additional oil should match with that of LG Electronic’s chiller oil. Added oil shall be recorded for its amount and date.

- Oil specification

Use oil recommended by LG.

Category

Density

Color

Ignition point

Total acid value

Unit kg/m

°C °C

3 mm

3

/s

Flowing point

Kinematic viscosity @ 40 °C mgKOH/g

@ 100 °C

Viscosity index

Characteristic value

960

Meaning

Check for the specified product and for any foreign substance mixed

L0.5

250

Check initially specified product

Fire and explosion risk, preservation stability

- 40

67.3

8.29

90

Stability during the initial start-up, preservation stability

Lubrication, friction loss, sealing effect, cooling capability

0.01

Relationship to the viscosity change due to temp. change

Measure oxidation of the oil itself compared to the initial total acid value

Corrosion of the copper plate

(100 °C, 3h)

1 Anti-corrosion ability of the oil

Table 27. Oil specification

<Available oils>

- Oil from LG

- Japan sun oil : Icecold SW68

- Castrol : Castrol Icematic SW68

• Oil replacement

We recommend you to replace the oil on the first year of the chiller's operation and every 3-year period depending on the oil analysis.

1) Mark the current oil level.

2) Open the control circuit breaker and oil heater circuit breaker.

3) Gradually open the oil charging valve to drain the oil. Opposite from the chiller pressure, open the valve very slowly.

4) After locking the valves at both ends of the oil filter, use the valve to gradually reduce the pressure within the oil filter, and change the oil filter.

5) Charge oil to the machine using a pump.

To be charged till the level of middle or higher at the sight glass, approximately 50~60 ℓ of oil is needed. Heat until the oil temperature reaches 40°C by turning on the oil heater. For the sake of controlling test, operate the oil pump manually for 2 minutes. The level of the oil should be indicating at the sight glass.

6. MAINTENANCE`

103

Oil Filter Change

- Oil Filter Change

Replace the oil filter annually or in the time of overhaul.

Oil filter can be replaced in a condition that the refrigerant is in the chiller.

1) Check if the compressor is in the stop state and also if the compressor circuit breaker is opened.

2) Shut down the oil pump power.

3) Close the oil filter separator valves.

4) When opening the oil filter housing, do it slowly.

!

CAUTION

Decrease the pressure of the oil filter housing very slowly because it is in a high temperature state.

5) Make vacuum in the filter housing after the filter exchange or assembling. After the vacuum has been done, open the separation valve and if there is insufficient amount of oil, add oil through the charging valve.

104

6. MAINTENANCE

6-6. General Maintenance

Non-periodical maintenance

• Maintenance of the compressor bearing and the gear

The core of maintaining bearing and the gear can be said adequate lubrication. Preserve the recommended oil amount, temperature and pressure by using the right level of oil. Do a thorough maintenance check-up on the lubrication system periodically. To inspect the bearing, the compressor must be completely disassembled.

To take out the bearing and to inspect it, a high technology specialist is needed. Excessive abrasion can occasionally be detected by excessive vibration or by the bearing's temperature.

• Refrigerant leak inspection

HFC-134a has higher pressure than air in room temperature, so it requires the refrigerant leak test utilizing electronic detector, halogen leak detector or soapy water.

If the refrigerant leak is overall the entire chiller with large volume, immediately stop using the system and fix it first. If the refrigerant was lost or the machine has been opened during the service period, the chiller itself or related tank must be taken leak test by adding pressure.

Refer to 5-5-2 for leak inspection.

Charging refrigerant and leakage test

- Refrigerant characteristics

Usage refrigerant is HFC-134a.

HFC-134a evaporates at -26°C in normal air pressure, so it shall be stored in a pressured container or storage tank.

Refrigerant has almost no smell when it is mixed with air, and it is non-combustible in air pressure.

!

CAUTION

The refrigerant HFC-134a dissolves oil and some non-metallic material, dries skin, and makes oxygen deficiency resulting in suffocation at high concentration. Thus be very careful not to inhale or touch by hand or eye contact when you handle the refrigerant.

<Characteristics Table>

Molecule formula

Molecule amount

Boiling point (air pressure)

Freezing point

Critical temp.

Critical pressure

Density of saturated fluid (25°C)

Specific volume of saturated vapor (25°C)

Specific heat ratio, vapor (25 °C, air pressure)

Evaporative latent heat (25°C)

°C

°C

°C kg/cm

2

.A

kg/m

3 m

3

/kg kcal/kg

Table 28. The property of HFC-134a

CH

2

F-CF

3

102.031

- 26

- 101

101

41.5

1206

0.031

1.1186

42.54

6. MAINTENANCE

105

- The adjustment of refrigerant charging amount

If it is necessary to control the refrigerant charging amount for a better performance of the machine itself, operate the machine in a design load and add or remove the refrigerant until it satisfies the difference temperature of the chilled water outlet and the evaporator refrigerant.

Do not over charge. Refrigerant can be charged through the storage tank or directly charged into the chiller.

- Refrigerant leak inspection

HFC-134a has higher pressure than air in room temperature, so it requires the refrigerant leak test utilizing electronic detector, halogen leak detector or soapy water. Check for a good room ventilation and check whether the leaked refrigerant is concentrated in one place of the room to prevent a wrong measurement result.

Before performing any repair for leak, move all refrigerant from the leaked container.

- Refrigerant leakage

If there is large refrigerant leak, chiller performance degraded or operation impossible, it is recommended to stop the chiller and repair first.

- Refrigerant filter

Refrigerant filter /drier in the refrigerant cooling pipes of the motor needs to be replaced once a year. It may require more frequent replacement according to the status of the filter. To find the existence of moisture in the refrigerant, sight glass is installed next to the filter. If moisture through the sight glass is detected, perform a thorough leak inspection to find the source of the water.

Cleaning Heat exchanger tubes (Evaporator/Condenser)

Inspect Heat exchanger tubes

- Evaporator

When the first operation season is over, clean the evaporator tubes.

These tubes have foreign substances inside. Thus to clean the tubes thoroughly, a special caution should be exercised. The tubes condition, at this time, will become the data to determine how often tubes needs to be cleaned and whether the water treatment in the chilled water(brine) system is appropriate. Check for any corrosion or scale in the chilled water inlet/outlet temperature sensor. For corrosion, replace the sensor, and for scale, remove the scale.

- Condenser

Cooling water circuit is generally an open type system, so it is easy to have the tubes contaminated and scale to be adhered. Therefore, the tubes in condenser need to be cleaned at least once a year. If the water quality is contaminated, clean more frequently. Check the corrosion or scale in the cooling water inlet/outlet temperature sensor. For corrosion, replace the sensor, and For scale, remove the scale.

The reason that it is higher than the normal condenser pressure and not reaching previous chilling load is generally because tubes are contaminated or there is an air in the machine.

If the temperature difference between cooling water outlet and condenser refrigerant is great, the condenser tubes may be contaminated or water flow is not good.

HFC-134a is a high pressure refrigerant, so it is easier to have refrigerant leak than air enters inside.

During the cleaning of the tube, use a specially designed brush to prevent scratch on the tubes wall.

Never use wire brush.

!

CAUTION

For the prevention of severe scales and the removal of the scales, treat with chemical. For a proper treatment, consult with water treatment specialist.

106

6. MAINTENANCE

Check items before operation after long term stop

- Check list before start-up

1. Control Panel and Electric lines

Shut down the breaker, check for any foreign substance in the control parts, switches, etc.. Controls the switches to check whether it operates in normal and connection status for each connector are OK.

2. Voltage

Read the voltage meter on the starter panel and check if it matches with the usage voltage on the name plate of the chiller.

3. Chilled and cooling water circulation system

Operate cooling water and chilled water pumps to check if their operation status are properly displayed on the panel.

- Control device operation test

1. Check the connection condition

Check if the power, sensor, etc. are properly connected.

Special checking should be taken to power line.

2. After power on, check the display status of the panel.

Pay special attention if there is any sign of short circuit for about 5 sec. after power on.

If any of the following symptoms occur, immediately disconnect power and check for problem.

3. Check values displayed on the panel

Check whether each sensor value displayed on the panel is correct.

If any error message is displayed or sensor value is not normal, check sensor connection status.

4. No power operation

Run while the main motor power is off, and check for normal operation to the operation signal of starter panel.

If any error message appears, check the corresponding part.

- Check safety devices

Flow operation test for chilled water and cooling water

Close the valves installed on the cooling water and chilled water pipes to check whether the flow checking switch is working correctly.

7. TROUBLESHOOTING

107


7-1. Causes and actions for alarms

Actions for problems

• How to react to the problem display from controller

• Please take actions according to the following instructions

Check the displayed contents and refer to the help message. Select help menu corresponding to the problem message and check the contents of the problem and how to react. Remove the cause of the problem according to the parts or drawing of the circuit related to the problem or manual. If the contents for the problem is no in the manual or drawing, consult our experts. Check the temperature control status, pressure status, etc.

Troubleshooting (1/3)

Abnormal category

Chilled Water Inlet temperature Sensor

Displayed contents

Chilled Water Inlet temperature Sensor Error

Cause

Sensor disconnected/short-circuit

Chilled water outlet temperature sensor

Chilled water outlet temperature sensor Error


Cooling water inlet temperature Sensor



Cooling water outlet temperature Sensor



Compressor discharge temperature sensor

Compressor discharge temperature sensor error


Bearing temperature sensor

Bearing temperature sensor problem


Motor winding R phase temperature sensor

Motor winding R phase temperature sensor error


Motor winding S phase sensor

Motor winding S phase sensor error


Motor winding T phase sensor

Motor winding T phase sensor error


Evaporator pressure sensor

Evaporator pressure sensor error


Condenser pressure sensor

Condenser pressure sensor error


Oil tank pressure temOil tank pressure temperperature sensor ature sensor error


Oil pump pressure sensor

Oil pump pressure sensor error


Current transducer

Voltage transducer

Current sensor error

Voltage sensor error



Action

Main board malfunction

Check parts status or wiring

Replace parts or re-wire`











































108



Abnormal category Displayed contents

Power transducer Power sensor error

Compressor discharge temperature charge temperature

Oil tank temperature

Compressor dishigh

Oil tank temperature high

Sensor disconnected / short circuit

Cause

Compressor discharge temperature is detected to be over set value

Oil tank temperature is detected to be over set value

Action



Replace parts or re-wire

Check compressor discharge temperature displayed on the controller screen.

Check the set value and correct if it is wrong.

Check oil tank temperature displayed on the controller screen.


Bearing temperature

Bearing temperature high

Bearing temperature is detected to be over set value

Check bearing temperature displayed on the controller screen.


Motor winding

R(S,T) phase temperature

Motor winding

R(S,T) phase temperature high

Motor winding R(S,T) phase temperature is detected to be over set value.

Check motor coil R(S,T) phase temperature displayed on the controller screen.


Condenser pressure

Motor Winding high temp. contact

Condenser pressure high

Motor Winding high temp. active

Condenser pressure is detected to be over set value

Motor winding high temp.

contact is active

Check condenser pressure displayed on the controller screen.

Check the set value and correct if it is wrong

Check motor winding temp.

Check winding high temp. contact status and wiring status

Chilled water outlet temp

Chilled water temp low Error

Chilled water outlet temp. is detected to be below set value.

There is no or small cooling load

Evaporator pressure

Check chilled water outlet temp. or temp. on the thermometer.


Evaporator pressure low

Evaporator pressure is detected to be below set value.

Check evaporator pressure displayed on the controller screen.


Oil differential pressure

Main power voltage

Oil differential pressure low

Main power voltage problem

Oil differential pressure is detected to be below set value.

Check oil differential pressure displayed on the controller screen.


Main power voltage is detected to be below set value.

Check the voltage of main power and the voltage set value.

Check the status of the related parts and wiring

Replace parts or repair

Starter panel abnormal

Starter panel abnormal

Starter panel abnormal, contact is active

Check the contact status of the starter panel and remove the cause of the contact.

Check related parts status or wiring

Replace parts of malfunction or re-wire

Check 2M magnet operating status.

Check the status of the parts or wiring


Start-up failed Start-up failed

During the start-up 2M magnet switch is not working

Chilled water pump

Interlock

Chilled water pump

Interlock Error

Pump interlock signal is disconnected during normal operation. Pump stopped

Wrong wiring

IO board malfunction

Cooling water pump Cooling water pump

Interlock Interlock Error

Pump interlock signal is disconnected during normal operation. Pump stopped.

Wrong wiring







109


Abnormal category Displayed contents

Vane closed switch Vane is not closed

Condenser high pressure

Condenser high pressure contact active

Cause

Start Vane Close

Switch is open

Action

Check vane closed switch operation status and wiring.

Adjust position of vane closed switch or re-wire

Condenser pressure is higher than the pressure switch set status

Check condenser pressure.

Check condenser high pressure contact status or wiring


Evaporator refriger-

Evaporator Refrigerant low temp.

ant Low Temp Contact Activate

Evaporator refrigerant temp.

is lower than the switch set status

Check evaporator refrigerant temp.

Check evaporator refrigerant low temp. contact status or wiring


Surge occurred

Oil pump

Surge occurred Surge occurred

Check surge current change amount

Reset the surge protection area

Oil pump overload contact active

Oil pump current is more than overload set current

Check oil pump overload setting status and wiring


Chilled water flow interlock

Chilled water flow low abnormal

Flow signal is disconnected during normal operation.

Pump stopped

Flow (differential pressure) switch setting problem.

Wrong wiring.


Correct set value and check

Check parts status or wiring.


Cooling water flow interlock

Cooling water flow low abnormal

Pump interlock signal is disconnected during normal operation.

Pump stopped

Wrong wiring.




Start-up competed signal (2M)

Delta contactor open during operation

Delta contactor signal is disconnected during operation

Evaporator refrigerant temp. low temp.

ant temp.

Evaporator refrigerproblem

Evaporator refrigerant temp.

is detected to be lower than set value

Communication

MAIN <-> I/O communication error

Communication error between boards



Check evaporator refrigerant temp. displayed on the controller screen.




Sensor correction

Set value is damaged. Sensor needs to be set

Sensor is not corrected Calibration using precision resistance device

Main board Main board reset

Display device Display board reset

Main board is reset during operation

Check voltage applied to the controller and wiring.

Remove cause of noise.

Display board is reset during operation

Check voltage applied to the controller

Remove cause of noise.

Check wiring

Table 29. Troubleshooting

110


Remedy for abnormal status

Vane sensor error

Fig 71. Vane sensor

Vane sensor

Release vane sensor connection from the relay board. After converting the tester to the resistance measurement mode, measure resistance between a and b, and there shall be a certain resistance. And after converting the vane to manual operation, when the vane is moved, there shall be vane sensor movement and change in resistance value.

Even if the vane sensor is moving but there is no change of resistance value, wiring is wrong or vane sensor is damaged. While vane is completely closed, and opened completely, if the resistance between a and b increases uniformly and resistance between b and c of the vane sensor decreases uniformly, vane sensor is OK. Also measure resistance between a, b, c, and main body, and it shall not be angle line.

If the vane sensor is normal, re-connect the sensor, completely close the vane, and check if vane value is 0% and

100% after completely opening. If the value changes and vane opening % is wrong, sensor needs to be set again.

If there is no change of value, check if 100% is set in ‘sensor setting-guide vane setting” category, and check if A/D value sensor value changes when vane moves. If sensor value changes, set vane again.

If sensor value does not change, convert tester to DC voltage 30V measuring position, and when voltage is measured with + at the point where vane sensor “a” is connected and – at the point where vane sensor c is connected, DC 5V must be measured.

If the voltage is not correct, check relay board main input power.

If relay main power is normal, vane sensor is normal, and sensor value does not change, then replace relay board.


111

Temp. sensor(PT-100) problem

A

B b

Fig 72. Temp. sensor

Release the temperature sensor connection from the controller and after converting the tester to resistance measurement mode, and when resistance between A and B, b is measured, the resistance shall be between 84.27

Ω(-

40°C) and 153.58

Ω(140°C). (If you check from PT-100 temperature table, you can find the value corresponding to the actual temperature) If the resistance value is outside the measurement boundary, connection is wrong or sensor is damaged. Connect resistance generator(Decade resistance box) to the controller and as changing to 0°C at 100.00

Ω,

10°C at 103.90

Ω, and 28°C at 110.9Ω, check if the temperature displayed on the controller changes according to the change of the resistance. If normal value is not displayed on the screen, check if the sensor is set correctly.

If the sensor value does not change when the resistance value is changed, check the main power of the main board again, and if power is normal and there is no sensor input value, Master or slave board needs to be replaced.

-130

-120

-110

-100

-90

-80

-70

Temp(°C)

-200

-190

-180

-170

-160

-150

-140

-20

-10

0

10

-60

-50

-40

-30

48

52.11

56.19

60.26

64.3

68.33

72.33

Rt (

Ω)

18.52

22.83

27.1

31.34

35.54

39.72

43.88

76.33

80.31

84.27

88.22

92.16

96.09

100

103.9

90

100

110

120

130

140

150

Temp(°C)

20

30

40

50

60

70

80

200

210

220

230

160

170

180

190

134.71

138.51

142.29

146.07

149.83

153.58

157.33

Rt (

Ω)

107.79

111.67

115.54

119.4

123.24

127.08

130.9

161.05

164.77

168.48

172.17

175.86

179.53

183.19

186.84

Table 30. PT-100 Temp. Table

310

320

330

340

350

360

370

Temp(°C)

240

250

260

270

280

290

300

380

390

400

410

420

430

440

215.61

219.15

222.68

226.21

229.72

233.21

236.7

Rt (

Ω)

90.47

194.1

197.71

201.31

204.9

208.48

212.05

240.18

243.64

247.09

250.53

253.96

257.38

260.78

Temp(°C)

450

460

470

480

490

500

510

520

530

540

550

560

570

580

590

600

610

620

630

640

650

287.62

290.92

294.21

297.49

300.75

304.01

307.25

Rt (

Ω)

264.18

267.56

270.93

274.29

277.64

280.98

284.3

310.49

313.71

316.92

320.12

323.3

326.48

329.64

112


4mA~20mA, 2-line type sensor, controller power used.

Check if the wiring between sensor and controller is properly connected.

4~20mA current input sensor problem occurred (pressure sensor)

Check if the setting value is properly set in sensor setting menu for 20mA.

Is it properly set?

N

Set the setting value again.

Measure current of the circuit.

(Refer to figure 76)

Is there current proportional to the measurement value?

Y

N

Measure the current of the sensor

(Refer to figure 77)

N

Is the wiring properly connected?

Master board / slave board

/display board error

Y

Wiring defect

Is the current of the sensor normal?

Check if the wiring between sensor and controller is properly connected.

Y

N

Sensor Error

- Check subsidiary power

- If subsidiary power is normal, replace the sensor

Figure 73. Pressure sensor


113

Pressure sensor

(+) (-)

(+) (-)

DC24V (+)

Controller board

Figure 74. Current loop measurement circuit

(+) (-)

- Place at DC 30V

- The measurement shall be within DC 22V±5%

DC24V (+)

Controller board

Figure 75. Controller voltage measurement circuit

Even if the inspection was carried out as above, if the cause couldn’t be found, connect current generator to the input connector(DC24V and (+)) of the controller and check if the indicator value changes according to the change of the current.

In such case, if the controller indicator value does not change according to the change of the current, it shall be decided as controller defect.

114


(-) (+)

Current sensor

- Place at DC30mA

- Measurement shall be between

4~20mA

(-) (+)

(-) (+)

- Place at DC30mA

- Measurement shall be between

4~20mA

(-) (+)

Controller board

Figure 76. Pressure sensor

(-) (+)

Current sensor

Figure 77. Current sensor measurement circuit

Digital input signal is not checked by the controller.

If the no voltage contact signal is properly input to the digital input of the controller but controller finds it as abnormal or if there is no change of all digital input signals, it is because of the defective connection of I/O board power connector or no communication between I/O board and main board.

Check communication line connection status between I/O board and main board, and it there is no problem, short-circuit the connector of the wiring among the controller digital inputs that does not work to COM connector (23, 24) of controller I/O board to check whether LED LAMP corresponding to the I/O board input connector is lighted.

Select “menu key” – “system information” – “I/O input” of the controller display, short-circuit/open abnormal connectors and COM connector to see if input status changes to “ON”/”OFF”.

When DC voltage between COM connector of the controller digital input and the wire released digital input, check if

18V is measured.

If there is no problem, connect them again and check operation.

If the corresponding board main power and communication is normal and I/O input still does not work the board needs to be replaced.

Check by referring to the below flow chart and tester connection diagram.


115

Digital input problem

Connect tester to the digital input channel with problem as in figure 79, and see if the input is normal.

Is input normal?

Y

Check controller power connector connection status.

N

Check normal operation of related wires and input sensor.

Is it properly connected?

N

N

Is connector connection normal?

Replace I/O board.

Y

Connect the cable firmly again.

Y

Measure voltage of the controller.

(refer to figure 80)

N

Is I/O board voltage normal?

Y

Check communication connection status between master board and slave board.

Is the main power of controller normal?

Replace main board.

N

Y

Figure 78. Digital input problem

116


D/I input

(-) (+)

- Place at DC30V

- If D/I input is open, measured voltage is within 18V±5%.

- If D/I input is closed, measured voltage becomes 0V.

Com connector(23/24) Corresponding input connector

Master or slave board

Figure 79. The current measurement circuit for master or slave board

- Place at DC30V

- Measured voltage shall be within

18V±5%.

Com connector(23/24) Corresponding input connector

Master or slave board

Figure 80. The current measurement circuit for master or slave board

Communication error

It is the error caused by no communication corresponding to the displayed message is made between each board.

First, check communication line connection status between each board. At this time, 2 RDX+ and RDX- lines of master board shall be connected to the same polarity of RDX+ and RDX- of slave board and relay board, and 2 RDX+ and

RDX- of master board shall be connected to the same polarity. If it is not properly connected to the corresponding communication connector, communication cannot be made, so it must be connected to the designated connector.


117

Abnormal rise of condensing pressure (cause of surge)

Status

Decision criteria

Cause Remedy

Temperature difference between cooling water outlet and condensing is large.

Above 3°C

1. Air is mixed into machine

2. Tube contaminated

3. Insufficient cooling water amount

4. Air taken in from cooling water pump intake

1. Clean tube

2. Check cooling water system and increase to specified amount

3. Enhance pump intake

Condensing pressure is high

9.5 kg/cm

2 or more

1. High Temp. Cooling water

▷ Lower the performance of cooling tower

2. Chilled water high temp.

3. Cooling water bypass in waterbox

4. Tubes contaminated

1. Check cooling tower performance

2. Lower chilled water temp.

3. Replace gasket in waterbox

4. Clean tube

Chilled water temperature is normal. However the temperature difference between the inlet and outlet of cooling water is large.

Check chiller data sheet

1. Cooling water amount decreased

2. Air taken in from cooling water pump intake

1. Check the cooling water system and increase to specified amount

2. Enhance pump intake

Table 31. Master or Slave board current measurement circuit

Abnormal drop of evaporator pressure (cause of surge)

Status

Evaporating pressure is low and chilled water inlet/outlet temperature difference is small

-

Decision criteria

Cause

1. Butterfly valve adjustment defect

2. Insufficient chilled water amount


4. Insufficient refrigerant amount

Remedy

1. Butterfly valve opening adjustment

2. Check chilled water system (flow)

3. Clean tube

4. Recharge refrigerant

Difference between evaporating temperature and chilled water outlet temperature is increased

Above 3°C

1. Insufficient charging of refrigerant

2. Contamination of refrigerant

3. Decreased chilled water amount

4. Air mixed in chilled water

5. Chilled water bypass in waterbox


1. Add refrigerant

2. Clean refrigerant

3. Check chilled water system and increase to specified amount

4. Enhance chilled water pump intake

5. Replace gasket in waterbox

6. Clean tube

Table 32. Cause and Action for drop of evaporating pressure

118


Problem in lubrication system

Status

Oil pressure is low

Decision criteria

Cause

(Oil discharge pressure – oil tank pressure)

< 0.8

kg/cm

2

1. Oil filter clogged

2. Insufficient oil

3. Pressure transducer defect

4. Oil pump defect

Remedy

1. Oil filter cleaning or replacement

2. Recharge oil

3. Change transducer

4. Check if oil supply valves are closed

5. Check if oil temp. is low

Oil temp. is high in oil tank

74°C or more during operation

1. Oil is not sufficiently supplied to bearing

2. Oil heater setting value defect

3. Refrigerant is not sufficiently supplied to oil cooler

4. Excessive oil amount

5. Bearing abrasion

1. Adjust oil pressure, and check oil filter, oil system.

2. Adjust set value

3. Check condensed refrigerant amount and filter drier.

4. Remove oil to make it adequate amount

5. Need disassembly and repair

Rapid change of oil pressure

-

1. Oil manometer defect

2. Oil pump cavitation

3. Insufficient oil

1. Change manometer

2. Apply power to oil heater

3. Recharge oil

Oil tank temp. is low

Below

30°C

Oil in oil tank increased when it is stopped

-

1. Oil heater fuse disconnected

2. Oil heater disconnected

3. Black out for long time, power unit stopped

1. Replace fuse

2. Replace oil heater

3. Wait until oil tank temperature meets the specified temperature. And if it does not rise, contact LG service personnel.

1. Oil temperature is too low and oil is dissolved by solvent.

1. Check whether oil heater is disconnected.

2. Make sure the oil heater is on when the chiller unit shut down for longterm.

Table 33. Cause and action for problem in lubrication system


119

Others

Status

Compressor discharge temp. is low

-

Decision criteria

Cause

1. Intake of fluid refrigerant

Motor overload

Abnormal vibration, current vibration

-

-

1. Extract adequate amount of refrigerant

Remedy

1. Chilled water inlet temp. is high

2. Intake of liquid refrigerant

3. Intake of oil

4. Condenser high pressure

5. Gauge defect

1. Adjust chilled water temp. set value

2. Extract refrigerant

3. Regenerate refrigerant

4. Refer to 6-2-1

5. Change gauge

1. Oil pressure is higher than specification

2. A lot of fluid refrigerant intake

3. Bearing gap is big

1. Adjust to specified pressure

2. Extract refrigerant

3. Disassembly and inspection

Abnormal sound in compressor main body

-

Abnormal sound

Moisture indicator turns yellow during operation

-

-

1. Contact of the rotating part

2. Bearing abrasion, damage

1. Need to disassemble and repair

2. Need to disassemble and repair

1. Noise transferred from cooling water and chilled water pipe

2. Guide vane assembly defect

3. Isolation device defect

1. Apply flexible join and spring isolator in the pipes

2. Reassemble or replacement

3. Replace isolator device

1. Moisture is 30ppm or more

2. Moisture indicator defect

1. Drain moisture in the machine

2. Replace moisture indicator

Insufficient chilling capability

-

1. Condensing pressure is high

2. Evaporating pressure is low

3. Gauge defect

1. Refer to 6-2-1

2. Refer to 6-2-2

3. Replace gauge leak in shaft part capacity adjustment device

1. Shaft stop bolt is not tightened

1. Tighten stop bolt clockwise and check leakage

Table 34. Cause and countermeasure for chiller problems

120

8. OPERATION INSPECTION RECORD

8. OPERATION INSPECTION RECORD

8-1. Check list for operation record

Operation record table

R-134a (1-level/2-level), R-123

MODEL :

Manufacture NO. :

3

:

4

:

5

:

Measurement Category

Chilled water

Evaporator

Cooling water

Condenser

Oil

Compressor

Inlet pressure

Outlet pressure

Inlet temp.

Outlet temp.

Chilled water flow

Pressure

Refrigerant temp.

Inlet pressure

Outlet pressure

Inlet temp.

Outlet temp.

Cooling W. Flow

Pressure

Refrigerant temp.

TANK pressure

PUMP pressure

Differential pressure

Temp.

Current limit value

Operating current

Winding temp.

Temp. of Bearing

Discharge gas temp.

Vane opening

Diffuser opening

Others

A

°C

°C

°C

%

%

°C

°C m

3

/h kg/cm

2

°C kg/cm

2 kg/cm

2 kg/cm

2

°C

%

Unit 1

Hour:Min.

: kg/cm

2 kg/cm

2

°C

°C m

3

/h kg/cm

2

°C kg/cm

2 kg/cm

2

2

:

1. Chiller start time

2. Chiller stop time

3. Maintenance issues

6

:

4. Operation time

5. Number of start-ups

6. Moisture indicator color

7

:

Table 35. Operation record table

8

:

LG RCWF P(200-3000RT) Centrifugal Chiller Operation & Maintenance Manual

Assistant Bot

OPERATION & MAINTENANCE MANUAL

Water-Cooled Centrifugal Chiller

Please read this installation manual completely for safety before installing the product.

The purpose of this manual is to keep the user safe and to prevent any property damage. After reading this installation manual, please retain it for future reference thoroughly Installation work must be performed in accordance with this installation manual by authorized personnel only.

Model : RCWF***P(200~3000RT) www.lge.com

For your records

1. CAUTIONS FOR SAFETY _ WARNING/CAUTION

It can be dangerous when moving, installing and placing the system for its high pressure, electric devices and heavy weight especially when lifting the unit in a limited space(rooftop, lifted structure, etc.).

Please read carefully the warnings and cautions on this manual and the labels attached on the unit, and follow the instructions.

Please follow the following instructions to prevent any injury or property damage

• It may result in an injury or damages when neglecting the instructions on in this manual.

The seriousness of the result can be classified as the following signs.

• Please note that any failure of system resulted by user’s careless maintenance, natural disaster or the failure of the power cable shall not be warranted regardless of the warranty period.

• Please note that any part of this manual can be revised without notice for the product improvement.

WARNING

CAUTION

1-1. WARNING

1-2. CAUTION

Operation & Maintenance

CONTENTS

3

6

1. CAUTIONS FOR SAFETY

_ WARNING/CAUTION

1-1. WARNING

1-2. CAUTION

2. INTRODUCTION

10

10

11

11

12

2-1. General Information

2-2. System structure

2-3. Nomenclature

2-4. Name plate

2-5. Main unit conversions

27

28

29

68

71

3. STRUCTURE OF SINGLE

STAGE CENTRIFUGAL

CHILLER

14

15

3-1. Cycle of the chiller

3-2. Main components of the two stage centrifugal chiller

4. CONTROL SYSTEM

21

26

4-1. Components of control panel and main parts

4-2. Components of starter panel and main parts

4-3. Basic control algorithm

4-4. BMS support function

4-5. Control Screen (Product function)

4-6. Startup and Control sequence

4-7. Product protection function

5. START-UP

74

76

83

86

5-1. Delivery and Installation Check

5-2. Preparation for start-up

5-3. Start-up

5-4. Startup procedure after long-period of stoppage

5-5. System Shutdown

87

6. Maintenance

88

92

98

6-1. Maintenance criteria

6-2. Periodic maintenance

6-3. Maintenance during off-season

99 6-4. Annual maintenance(1/2)

Model : RCWF*P(200~3000RT) www.lge.com**