Maintenance. Mammoth V-Cube

Airflow.Balancing

IMPORTANT

Before measuring supply and exhaust flows, the building must be in its normal state:

• Hermetically close doors and windows.

• Shut down hot air generators and combustion water heaters.

• Install all ventilation system components: filters, grilles, diffusers, etc.

For proper performance the unit must operate at the specified supply and exhaust flow rates as shown in the mechanical drawings. Unit fan speed(s) and damper positions are theoretically set at the factory based on the ductwork static pressures and flow rates specified in the mechanical drawings. If conditions change or verification is required, airflow measurements should be taken using AMCA suggested methods. This would normally be a velocity traverse measurement or flow measuring station (FMS) installed in the ducts. Where space is limited in the outdoor air and exhaust air, pressure drop readings can be taken across the energy recovery heat exchanger (with economizer heat recovery bypass dampers closed, if equipped) and compared to the submittal documents. Heat recovery performance is tested in accordance to AHRI Standard 1060 and is accurate to within +/− 5% if there is no dirt buildup in the heat recovery heat exchanger. Should flow rates need to be reset, adjust the outside air, exhaust air or mixed air dampers, variable speed sheaves, VFD fan speed setpoint positions or change the sheaves.

Flow measuring stations (FMS) and magnahelic gauges can also be used to measure supply and exhaust flow. It is important to locate the FMS in the “warm side” ductwork to minimize the effect of differences in air density, especially when balancing during extremely cold outside conditions or to take temperature readings and make the necessary corrections if installed in the “cold side” ductwork. Air density variations can affect the FMS by more than 15%.

The FMS should be located downstream in straight sections of duct and not immediately after fans or obstructions that will cause turbulent flow.

If the unit has been in operation before the air balancing, ensure the unit filters are clean or include pressure drop readings across the filter banks with the report.

Maintenance

Long-term.Storage.Maintenance.Procedures

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Please refer to

Appendix F : Extended Dormant Unit Main-

tenance Procedure and Checklist, for maintenance instructions to follow if the unit is to be stored for a period of time exceeding one month. Following the instructions in this appendix will assist in preventing potential unit damage that may result from an extended storage period.

Maintenance.Summary.Chart

Please refer to Appendix G

for a recommended list of routine maintenance items and time intervals. A more detailed description of maintenance items follows.

VCES-V-CUBE-IOM-1A 16

Refrigerant.Systems

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Compressors

Scroll-type compressors are the most common type of compressor used by Venmar CES. Other types of compressors are available upon request, if required. Maintenance and service on compressors must be completed by a licensed service mechanic. Provincial or state regulations frequently require such qualifications for compressor maintenance. If a compressor cycles, leaks or has any defects, contact Venmar CES as soon as possible.

Water Cooled Condensers

Shell.and.Tube.Condensers

Most integrated water cooled units contain shell and tube condensers. Periodically, water tubes should be mechanically cleaned to ensure optimum condenser efficiency. Frequency of cleaning will depend on individual water conditions, so a suitable cleaning schedule should be arranged based on experience and knowledge of the building or local water supply loop. Cleaning brushes are available from most refrigeration supply outlets. For better results, always remove both heads before cleaning water tubes.

Note that head gaskets do not require renewing at every maintenance operation. However, if the head gasket is physically disfigured or deteriorated in any way, the system will require new gaskets in order to retain the water-tight seal required for correct system operation.

Evaporator Section

The direct expansion coil is constructed of seamless copper tubing expanded into full collared aluminum fins. The tubes are arranged for a counter flow circuit and staggered to provide maximum heat transfer. A pressure type distributor with hot gas inlet port and a heavy duty copper suction header are included. Additional refrigerant circuit components include thermostatic expansion valves with external equalizer and hot gas bypass valves on the full face of the leaving side of the direct expansion coil (HGBP option is removed when optional digital scroll compressors are utilized).

Components of a Direct Expansion (Dx)

System

The evaporator is that part of the low pressure side of the refrigerant system in which the liquid refrigerant boils or evaporates, absorbing heat as it changes into a vapor.

Distributor

Liquid line

Hot gas bypass line

Suction line

Expansion valve

Check valve on remote condensing application (optional)

Figure 11: Direct expansion (Dx) coil

Evaporator coil

Thermostatic Expansion Valve

The thermostatic expansion valve (TXV) is a precision device designed to meter the flow of refrigerant into the evaporator, thereby preventing the return of liquid refrigerant to the compressor. By being responsive to the temperature of the refrigerant gas leaving the evaporator and the pressure in the evaporator, the thermostatic expansion valve can control the refrigerant gas leaving the evaporator at a predetermined superheat. Three forces that govern the operation of the TXV are:

1. The pressure created by the remote bulb and power assembly (P1).

2. The evaporator pressure (P2).

3. The equivalent pressure of the superheat spring (P3).

Bulb clamp

Remote clamp

P

1

Diaphram

P

2

External equilizer port

P

3

Figure 12: Thermostatic expansion valve (TXV)

VCES-V-CUBE-IOM-1A 17

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Units from Venmar CES may or may not incorporate the use of dampers. If dampers are present within the unit, the following maintenance should occur in order to prevent the unit from working under too much pressure and to prevent any other issues.

Dampers must be kept free of foreign matter that might impede normal free movement. Bearings between blades and frames are made of polymer and require no maintenance. Note that the damper shafts do not need lubrica-

Dampers

tion. All Venmar CES dampers and linkages are assembled with non lubricating bearings.

• Attachment mechanism linking motors to dampers should be checked for tightness.

• Damper jackshafts (if provided) are fitted with grease nipples and should be lubricated once a year. Use a premium quality lithium based grease conforming to NLGI Grade 2 or 3 (examples are: Mobil Mobilith

AW2, Chevron Amolith #2, Texaco Premium RB or

Shell Alvania #2).

• Dampers should be inspected for dirt; check the shaft, arms, bars and controls rod every three months.

• Inspect the seals to ensure none have pulled loose or deteriorated. If a seal has been damaged, repair or replace it with the same seal or same seal material.

Contact Venmar CES for replacement parts.

Belt driven fan, motor and drive assemblies should be checked and inspected at regular intervals per the inspection list and procedures below. Listen for vibrations or unusual sounds. Severe damage, premature failure and loss of airflow can be avoided by regular inspection and maintenance.

1. Check the fan, motor and bearing mounting bolts for tightness according to the bolt torque chart in Table

1 below at time of start-up, after 24 hours, then every three months.

Table 1: Minimum head bolt torque in lb-ft (Grade 5 bolts)

1/4 –20

1/4–28

5/16–18

5/16–24

3/8–16

3/8–24

7/16–14

7/16–20

1/2–13

1/2–20

9/16–12

9/16–18

5/8–11

5/8–18

3/4–10

3/4–16

7/8–9

7/8–14

1–8

1–14

Size (Inches) Thread Designation Minimum Torque

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

UNC

UNF

69

83

99

118

150

176

254

301

24

28

42

45

6

7

14

16

358

422

500

602

Soft metric conversions are not acceptable for screw and hex sizes.

VCES-V-CUBE-IOM-1A

Belt.Driven.Fans

2. Check the fan wheel hub, bearings and drive sheave set screws for tightness according to the set screw torque chart in Table 2 below at time of start-up, after 24 hours of operation, monthly for the initial three months then every three months thereafter.

If wheel or bearing set screws have worked loose, check the wheel for any signs of movement (inlet space clearance between the fan wheel and housing) or loose blades. If Loctite was used on any set screws that have come loose, the set screws must be removed and cleaned before re-tightening and Loctite must be re-applied.

Table 2: Wheel set screw torque in lb-ft

Set Screw Size

Diameter (Inches)

1/4

5/16

3/8

7/16

1/2

5/8

3/4

Carbon Steel Set Screw Torque* lb-in lb-ft

75

144

252

396

600

1,164

2,016

6.2

12.0

21.0

33.0

50.0

97.0

168.0

7/8 3,204 267.0

1 4,800 400.0

*Stainless steel set screws are not hardened and should not be tightened to more than half the values shown.

18

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Table 3: Bearing set screw torque in lb-in

Set Screw

Diameter

#10

1/4

5/16

3/8

7/16

1/2

Link

Belt

40

90

185

325

460

680

—

Manufacturer

Sealmaster SKF

65

125

230

350

500

35

50

165

290

350

620

McGill Dodge

35

85

165

290

—

—

—

—

160

275

—

600

5/8 1,350 1,100 1,325 — 1,200

3/4 2,350 — — — 2,000

Split pillow block bearings are fixed to the shaft with tapered sleeves and generally do not have set screws.

3. Check each V-belt tension and adjust 3. the motor base for correct amount according to the deflection outlined in the Measuring Belt Tension procedure below and in

Appendix H for type of belt at time of

start-up, daily for the first week until they should acquire their permanent set, then monthly. All belts should have approximately the same amount of deflection. Be aware of mismatched or worn belt sets.

If a belt must be changed, ensure to change all belts on the same drive at the same time. Never replace just one belt within a set.

Measuring Belt Tension a. Measure the belt span with a span scale.

b. Divide the belt span by 64 to determine the belt deflection needed to check tension.

c. Set the O-ring on the span scale to the required deflection value.

d. Set the small O-ring at zero on the force scale.

e. Place the scale end of the tension checker squarely on one belt at the center of the belt span. Apply force on the plunger until the bottom of the large O-ring is even with the top of the next belt or until it is even with a straight edge laid across the sheaves.

f. Read the force scale under the small O-ring to determine the force required to give the needed deflection.

g. Compare the force scale reading in Step F above with the correct value for the belt style and cross section. The force scale reading should be between the minimum and maximum values shown in

Appendix H .

VCES-V-CUBE-IOM-1A h. If the deflection value is below the minimum, tighten the belts. If the deflection value is above the maximum, loosen the belts. The tension on new belts should be checked during the first day of operation, at the end of the first week and monthly thereafter.

4. Check the fan and motor sheave alignment using a straight edge along the outside edges of the sheaves

for equal sized fixed sheaves as shown in Figure 13 and Figure 14 at time of start-up, after 24 hours

of operation, monthly for the initial three months, then every three months thereafter. When properly aligned the straight edge should touch the full face of both sheaves. With one adjustable and one fixed sheave with unequal sizes, use a string placed at the center grove of both sheaves pulled tight to check alignment. Adjust sheaves for proper alignment and set screws to proper torque.

Center lines must coincide

Lines must be parallel

Fixed sheave

Straight edge

Figure 13: Equal sheave size alignment

Adjustable sheave

Figure 14: Unequal sheave size alignment

5. Belt driven fan bearings are fitted with grease nipples for lubrication. The grease quantity and lubrication interval depends on bearing (fan size) and rpm and are indicated in Tables 4 and 5. Use a premium quality lithium based grease conforming to NLGI Grade

2 or 3 (examples are: Mobil Mobilith AW2, Chevron

Amolith #2, Texaco Premium RB, Shell Alvania #2 or Esso Beacon #325). Clean the grease nipple first, then rotate the fan shaft slowly by hand while adding grease. The lubrication intervals are theoretical and will depend on site conditions, hours of operation and temperature. It is recommended to make periodic inspections of the bearings before these theoretical intervals.

19

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Table 4: Recommended Grease Quantity

Shaft Size

Inches Millimeters

Maximum Grease Capacity of Bearing Chamber

Ounces Kilograms

0.500–0.750

0.875–1.187

1.250–1.500

1.687–1.937

2.000–2.437

2.500–2.937

3.000–3.437

3.500–4.000

4.187–4.937

13–19

25–31

32–38

43–49

51–62

63–75

76–87

89–102

106–125

0.125

0.375

0.625

0.875

1.250

2.000

3.500

6.000

10.000

0.004

0.011

0.018

0.025

0.035

0.056

0.098

0.168

0.280

Table 5: Generally Recommended Relubrication Frequency in Months

Operating

Speed (RPM) up to 500

0.500–1.000”

[13–35 mm]

6

1.125–1.500”

[28–38 mm]

6

1.625–1.937”

[41–49 mm]

6

500–1,000

1,000–1,500

1,500–2,000

2,000–2,500

2,500–3,000

3,000–3,500

3,500–4,000

4,000–4,500

4,500–5,000

4

3

3

2

2

5

4

6

5

3

2

2

1

1

4

4

6

5

2

2

1

1

—

4

3

6

5

6. Fan, wheels, housings and drive assemblies 6. should be checked for dirt buildup annually and cleaned if necessary to keep them from becoming unbalanced and to prevent loss of airflow. Clean with compressed air to reduce any dirt, dust, lint or larger particulates that have bonded to the fan impeller housing or drive assembly. Block dirt from entering the unit and ductwork if necessary or remove fan assembly from unit. Alternatively use low pressure steam, a degreaser and rag. If a sheave requires cleaning, detergent and water can also be used. Ensure the belt is dry before starting up the unit.

IMPORTANT

Be careful not to remove or dislodge balancing clips on the fan blades while cleaning.

2.000–2.500”

[50–63 mm]

6

5

4

1

2

3

2

—

—

—

2.687–3.187”

[68–81 mm]

5

4

3

2

—

2

1

—

—

—

3.437–3.937”

[87–100 mm]

4

3

3

1

—

—

—

—

—

—

VCES-V-CUBE-IOM-1A 20

FANWALL

®

.Array

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Maintenance Schedule

FANWALL array of multiple direct driven plenum fan and motor “cubes” are equipped with permanently sealed bearings and do not require lubrication. The following maintenance schedule is recommended.

1. Monthly a. Check the fan wheel to inlet cone alignment for possible noise from the wheel rubbing against the inlet cone. See Fan Wheel/Cone Alignment below for instructions.

2. Every six months a. Check motor bearings for possible binding noise or overheating.

b. Check fan wheels for dirt and grease accumulation. Clean as necessary. Do not use any caustic cleaning solutions.

3. Annually a. Lightly lubricate damper and linkage bushings on backdraft dampers (if equipped).

4. Every two years a. Examine fan housings and motor pedestal for corrosion. Clean and touch up with paint as necessary.

Figure 16: Remove safety screen on motor end

3. Disconnect the four-wire electrical cable from the motor junction box. Make note of wire locations for

reinstallation later (see Figure 17).

Figure 17: Remove electrical cable

4. Mark motor pedestal location on the motor pedestal mounting angles (both sides), then loosen and remove (four) ½” bolts that retain the motor pedestal

to the mounting angles (see Figure 18).

Figure 15: FANWALL array

Fan Wheel and Motor Removal

1. Disconnect power to the fan array control panel before maintenance. Follow all lockout and tag out procedures.

2. Remove the optional safety screen (if provided) on the motor end only of the cube in question by removing all four hex screws from the holding flange

that retains the safety screen (see Figure 16).

VCES-V-CUBE-IOM-1A

Figure 18: Remove motor pedestal retaining bolts

21

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

5. After removing the motor pedestal 5. retaining bolts, slide the motor/fan/pedestal assembly out to the point where the motor lifting ring is clear of the cube frame enough to use. If a mechanical device is available for use, attach it to the motor lifting ring. Lift and remove the motor pedestal with motor and fan wheel from the cube. The motor pedestal with motor and fan wheel can be turned 180º and slid back into the cube on the pedestal mounting angles or removed from unit for further disassembly.

6. Mark the location of the trans-torque bushing on the shaft and the fan. To remove the fan wheel from the motor shaft, remove the trans-torque bushing retaining hex nut using a 1” socket with a 12” extension by turning counter clockwise. Loosen progressively until the bushing is free from wheel hub and motor shaft.

Remove fan wheel/hub assembly (see Figure 19).

Figure 19: Mark location and remove trans-torque bushing and fan wheel from motor.

7. If needed, the motor may now be removed for service by removing all (four) 3/8” motor retaining nuts and bolts. Be sure to mark the motor base pattern and bolt holes used on the motor pedestal. Rubber isolator pads between the motor base and the pedestal are optional and if supplied be sure not to lose

them (see Figure 20). If the motor is to be replaced,

make sure to remove the shaft grounding ring off the front of the motor that is being replaced. Install the shaft grounding ring onto the new motor by drilling and taping mounting holes. Use a 7/64” or a #35 drill bit and #6-32 tap. Clean away any chips and shavings before installing the shaft grounding ring.

VCES-V-CUBE-IOM-1A

Figure 20: Remove motor retaining bolts; do not lose rubber isolator pads (if provided).

8. To reinstall the motor, fan wheel and fan wheel/ motor/pedestal assembly back into the cube, reverse the steps above noting the following: a. Insert the (four) 3/8” motor retaining bolts into the holes in the motor pedestal from the underside, make sure to use a standard washer on the bolt side, install the rubber isolator pads (if supplied) between the pedestal and motor base and only a locknut is required on the motor side.

b. Square the motor on the pedestal according to markings and tighten the bolts. With rubber isolator pads tighten the bolts to 20 ft-lbs. Without rubber isolator pads tighten the bolts to 40 ft-lbs.

c. Install the fan wheel on the motor shaft with the hub facing towards you. Line up the markings on the hub/trans-torque bushing/shaft. Make sure that the trans-torque bushing nut is flush to the hub. Tighten the bushing nut progressively to 80 ft-lbs turning clockwise.

9. Lift the motor pedestal with motor and fan wheel

(turn 180º if placed on the pedestal mounting angles for disassembly) with the fan wheel inlet toward the inlet cone. Place motor pedestal into the cube on the pedestal mounting angles and slide the pedestal forward to the line that you previously marked. Line the four pedestal bolt holes up with the bolt holes on the mounting angles. Insert (four) ½” bolts into the holes, make sure to use a standard washer on the bolt side and a standard washer and lock washer on the nut side. Hand tighten the bolts for now.

10. Check the inlet cone alignment to the fan wheel. Fan wheel should not be rubbing against the fan inlet cone when rotated by hand. The fan wheel to inlet cone clearance should be approximately 1/16” gap

and the overlap should be as indicated in Appendix

I

for the fan wheel size. Adjust the overlap of the wheel and cone by moving the motor pedestal for-

22

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

ward or backward. Fan wheel should not be rubbing on the inlet cone. If cone alignment is required see instructions for Fan Wheel/Cone Alignment below.

Once alignment and overlap are correct tighten the

(four) ½” pedestal mounting bolts to 90 ft-lbs.

sembly can be performed. Note the directions of the damper blades are running vertical. The damper is installed directly onto the FANWALL® cube inlet side panel and over the optional airflow straightener (if supplied).

Figure 22: Fan wheel/cone alignment – Step 2a

Figure 21: Check fan wheel/cone alignment and overlap.

11. Reconnect the four-wire electrical 11. cable from the motor junction box. Before operation, start the motor slowly to ensure the fan rotation is correct.

If the fan wheel is not rotating correctly, check the motor leads for proper installation.

a. Drive side – Clockwise rotation when looking at motor end.

b. Inlet side – Counter clockwise rotation looking at fan inlet.

IMPORTANT

Before restarting, re-balance the fan wheel once the motor rotation and alignment have been corrected before placing the unit in operation.

Fan Wheel/Cone Alignment

1. To align fan wheel/cone, first disconnect power to the fan array control panel. Follow all lockout and tag out procedures.

2. If the optional backdraft damper is furnished on the inlet side of the fan it must be removed first. Remove all tek screws on all sides attaching the damper frame to the inlet side panel and remove it from the cube. The purpose of the damper is so that maintenance staff can block the intake of a single fan to prevent back flow until service on an inoperative as-

VCES-V-CUBE-IOM-1A

Figure 23: Fan wheel/cone alignment – Step 2b

3. If the optional airflow straighteners are furnished on the inlet side of the fan it must be removed next. Remove all tek screws on the airflow straightener panel frame and remove it from the cube.

Figure 24: Fan wheel/cone alignment – Step 3

23

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

4. Gently rotate the fan wheel to verify location of adjustment required.

7. Gently rotate the fan wheel to verify cone adjustment for proper clearance from wheel.

Figure 28: Fan wheel/cone alignment – Step 7a and Step 9a

Figure 25: Fan wheel/cone alignment – Step 4

5. To make adjustment, loosen (do not remove) all the cone retaining fasteners.

Figure 29: Fan wheel/cone alignment – Step 7b and Step 9b

8. Tighten all the cone retaining fasteners.

Figure 26: Fan wheel/cone alignment – Step 5

6. Using a rubber mallet, gently tap around the cone until desired clearance is acquired between fan wheel and inlet cone.

Figure 27: Fan wheel/cone alignment – Step 6

VCES-V-CUBE-IOM-1A

Figure 30: Fan wheel/cone alignment – Step 8

9. Once again gently rotate the fan wheel to verify cone alignment.

10. To install the optional airflow straightener or backdraft damper reverse the steps above.

24

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Blank-off Plate (if applicable)

1. Optional blank-off plate(s) are available so that maintenance staff can block the intake of a single fan to prevent back flow until service on an inoperative as sembly can be performed or it can be mounted on spare FANWALL put into service.

® cube(s) until they are required to be

2. First disconnect power to the fan array control panel.

Follow all lockout and tag out procedures.

3. The blank-off plate is fitted to the inlet side of the

FANWALL cube on the optional airflow straightener panel frame (if supplied) or onto a matching

“Z” frame. There are 12 pre-drilled holes which are located in the corners and middle of the airflow straightener panel frame or “Z” frame matching predrilled holes in the blank-off plate for fastening together with tek screws.

4. Place the blank-off plate over the optional airflow straightener panel frame (if supplied) or onto the matching “Z” frame and pre-drilled holes and fasten together with or remove tek screws.

Figure 32: Blank-off plate – Step 4

Figure 31: Blank-off plate – Step 3

VCES-V-CUBE-IOM-1A 25

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Motors will operate effectively for years if they are kept clean, dry and properly lubricated. An excessive running current is a good indication of the overall condition of the motor. Check the following items every six months (unless otherwise indicated) for proper performance:

• Motors must be cleaned with moderate air pressure

(around 25 to 30 psi). Dirt must be blown away from vent fins and all other accessible areas. All areas surrounding the motor must be kept clear so air can circulate freely to cool the motor.

• Ensure all connections are secure. Look for loose wires and loose contacts. Repair and tighten any defective connection.

Motors

• Ensure the motor is operating at the current indicated on the nameplate. If not, a physical or electrical restriction is working against the motor and it must be repaired.

• Ensure the motor is not vibrating too much. A significant vibration can come from a loose mounting bolt or an unbalanced impeller. If significant vibration has occurred, be sure to repair it and inspect the mounting base and the flexible duct connection for any damage.

• Motor lubrication must occur once a year when grease nipples are provided with a premium quality lithium based grease conforming to NLGI Grade 2 or

3 (examples are Mobil Mobilith AW2, Chevron Amolith#2, Texaco Premium RB, Shell Alvania #2 or Esso

Beacon #325). Clean the grease nipple first, then rotate the motor shaft slowly by hand while adding grease with a low pressure grease gun. Do not over lubricate!

Standard 2” [51 mm] and 4” [102 mm] prefilters are disposable and should be replaced every three months or sooner if the pressure drop across the filters is too great.

High efficiency filters (optional) should be replaced when dirty. Venmar CES recommends that they be used only in combination with 2” [51 mm] or 4” [102 mm] prefilters in order to protect them from premature clogging and to

increase their effective lifespan. The tables in Appendix J

provide data relative to the pressure drop across clean fil-

Filters

ters and indicate the type of reading that should be given on the magnahelic gauge. The data relative to accurate pressure drop across the filters is available in the submittal. If the system is equipped with both prefilters and final filters, it is recommended that prefilters be changed twice as often as final filters. Running a unit with dirty and inefficient filters will lower the airflow and thus lower the air quality of the area.

Dirt on the surface of the coil reduces its ability to transfer heat which lowers the efficiency of the unit, resulting in poor air quality and expensive operating costs. Because of the condensate on the coil, the dirt often becomes wet and contributes to the growth of microbial organisms.

Negligence in maintenance may result in serious health related indoor air quality problems. The coil should be kept clean for maximum performance. To achieve maximum efficiency, clean the coil often during periods of high demand or when dirty conditions prevail. Venmar CES recommends cleaning the coil a minimum of once per year to prevent dirt buildup in the coil fins where it may not be visible.

Coils

CAUTION

Do not use acidic chemical coil cleaners. Do not use alkaline chemical coil cleaners with a PH value greater than

8.5 or lower than 6 (after mixing) without using an aluminum corrosion inhibitor in the cleaning solution. Using these types of cleaners may result in unit damage. Coil fins can be cleaned by using steam with detergent, hot water spray or a commercial chemical coil cleaner. After cleaning the coil, be sure to rinse thoroughly.

VCES-V-CUBE-IOM-1A 26

!

WARNING

Many of the following steps need to be performed with the unit powered off and locked out. Disconnect the main power switch to the unit before performing service and maintenance procedures.

Cleaning Procedure

1. Shut down the unit by closing the main disconnect at the power inlet.

2. Open panels or doors to gain access to both sides of the coil section.

3. Remove soft debris from both sides of the coil with a soft brush.

4. Using a steam cleaning machine, clean the leaving air side of the coil first (going downward) then clean the entering air side. Use a block-off to prevent the steam from penetrating a dry section of the unit.

5. Allow the unit to dry thoroughly before restoring power.

6. Damaged coil fins should be straightened by using a fin comb.

7. Close all panels and doors once the coil is dry.

8. Restore electrical power to the unit.

Controls

General controls information regarding the navigation and monitoring of your unit with the standard keypad, DDC points list, ladder diagram and specific sequence of operation or required network communication is included in the documentation that is contained in the control panel of your unit. Please contact the factory if this information is missing or has been lost.

See Appendix K

for trouble shooting information.

Troubleshooting

VCES-V-CUBE-IOM-1A 27