JTL USER GUIDE CONTROLLER TYPE:

LAPI

Electrical Installation Requirements

Care should be taken to separate the power and signal cables to prevent electrical interference and possible damage due to inadvertent connection.

The power outputs are fitted with suppressors to protect against electrical interference when switching off solenoid valves or contactors. It is therefore essential to observe the output polarity. The line voltage should be connected to the terminals marked LN and the switched loads to NO or NC.

The plant inputs are electrically isolated. A line voltage should be connected for the logical conditions lighting override and shutdown. The terminals marked C should be connected to the supply voltage neutral.

CE Conformance

This unit conforms with the relevant EU standards when installed according to the JTL Installation Requirements for this product

Refrigerant Type

This controller will operate for Carbon Dioxide (R744) and various HFC refrigerants as well as HCFC type R408A. The refrigerant choice is made on item 157. CO

2

(R744) operation is only allowed for frozen food applications and requires the pressure transducer to be selected as -1 to 34 bar (item 175 set to 3). Other refrigerants require the transducer to be -1 to 7 bar (item 175 set to 4).

Control Strategy

The controller can control to the cabinet temperature or the air off temperature selected using item 275.

The control strategy for HGD/well operation is that the temperature is controlled to the worst case of the 2 sections. Each case section has its own temperature factor to enable the case temperature to be calculated from the air on and air off temperatures.

The air off temperature is controlled to a computed setpoint shown on item 28, by controlling pulsed expansion valve.

OUTPUT 1

OUTPUT 2

OUTPUT 3

OUTPUT 4

OUTPUT 5

1

NO

LN

NO

4 LN

NC

5

NO

NC

2

NO

LN

3

NO

LN

CON3

RL1

RL2

RL3

RL5

RL4

CON4

CON66

CON8

TEMPERATURE

SENSORS

AIR ON

AIR OFF

EVAPORATOR

SUCTION

TERMINATION

-

+

AIR ON 2

SUCTION PRESSURE

BL

RD

JTL NETWORK

WIRING

TO JTL DISPLAY

Inputs

Input (CON 2)

INPUT 1

INPUT 2

N1

C

N2

C

CON2

CON55

CON7

BL

RD

JTL NETWORK

WIRING

TO JTL DISPLAY

I1

C

I2

C

(LINE)

(NEUTRAL)

(LINE)

(NEUTRAL)

SHUTDOWN

LIGHTING

OVERRIDE

Where the second case option is selected, 2 displays can be driven. This is selected using item 502. If this option is selected a JTL display splitter is required. Either of the displays support the keyswitch function but it is not recommended that both displays be keyswitch type.

The LCD9 display incorporates a keyswitch. This switch can be used to select various functions as described below. A maximum of 2 additional functions can be selected. On LCD9 if only one additional function is selected, then it is available in either of the extra 2 positions.

The CAB55 cable is available in various lengths.

The computed air off temperature setpoint is calculated by comparing the displayed temperature with the cabinet temperature setpoint. The computed setpoint is raised or lowered depending on whether the cabinet temperature is below or above the cabinet temperature setpoint. The computed air off setpoint cannot go below the value set on item 31.

Backup Defrost Initiation Strategies

For network initiated defrost, 2 defrost backup strategies are included. The strategy choice is made on item 107.

For learned backup the last 24 hours defrost operation is continuously monitored and the defrost schedule is learned. For real time backup the defrost schedule as set up for real time defrost on items 51-56 is used.

If network communication fails, the selected backup strategy is automatically used. The unit reverts to network control whenever the network communications is operational.

230V 1ph

50Hz 1A

N

L

E

CON1

Temperatures and Pressure (CON 4)

1, 2

3, 4

5, 6

7, 8

9, 10

11, 12

13, 14

AIR ON TEMP

AIR OFF TEMP

SUCTION LINE

EVAPORATOR

ENERGY SAVING OR TERMINATION

AIR ON 2 TEMP

SUCTION PRESSURE - +

The LAPI controller can be set to operate from 2 cabinet temperature setpoints by setting item 123. The setpoint to be used is then selected using the display keyswitch. The setpoints are set on items 124 and

125 and the current setpoint is displayed on item 30.

Supeheat Control

The superheat control can be set to operate in 3 ways using item 188.

a) SUCCEEDS. In SUCCEEDS strategy the air temperature is controlled and the superheat allowed to float.

Outputs

Outputs (CON 3)

1 NO

1 LN

OUTPUT 1 (N/O LOAD)

(LINE)

LIGHTING & BLINDS

CONTACTOR

The pulsed expansion valve opening is controlled primarily using a PI strategy on the control temperature. The valve is opened and shut over a fixed period of time (6.25 s) to meter the appropriate amount of refrigeration. The proportional gain and the integral time constant for the PI control are adjustable.

2 NO

2 LN

OUTPUT 2 (N/O LOAD)

(LINE)

FANS / HEATERS b) SUCCEEDS with limit. The superheat is allowed to float to the maximum set on item 189. If the case control temperature error is negative and the superheat is greater that the maximum set on item 189 the expansion valve is closed. It is reopened again with a deadband adjustment on item 140.

3 NO

3 LN

OUTPUT 3 (N/O LOAD)

(LINE)

TRIM HEATER

4 NO

4 LN

4 NC

OUTPUT 4 (N/O LOAD)

(LINE)

(N/C LOAD)

DEFROST c) Fixed. The superheat is controlled using PI control on the superheat temperature. When the case temperature is achieved the PEV is shut. It is reopened again with a deadband adjustment on item 140.

5 NO

5 LN

OUTPUT 5 (N/O LOAD)

(LINE)

PULSED EXPANSION

VALVE

In all cases if the superheat falls below the minimum level set on item 162 or

186, the PEV is progressively shut to effect recovery from excess liquid supply.

This is called override.

Use of Maintenance Unit

The controller can be checked and the operation adjusted using a JTL portable maintenance unit which plugs into the controller. Each item of information has an item number. The more important items are listed in the tables overleaf.

After override is complete, ie. superheat recovers, PI control will be resumed but with a modified (reduced) value. The modifier is shown on item 190 and the output to the PEV valve is shown on item 168.

The superheat is calculated using the suction pressure and temperature. A backup strategy uses the evaporator and suction line temperatures to calculate the superheat.

Examples:

To read item 21 press:

To set item 31 to -20.0

To correct errors press: press:

Pressure Transducer Failure Strategies

There are 3 strategies (set on item 177):

1. Open circuit. Automatic switch to 2 temperature control and raise transducer fault alarm.

2. Auto zero adjust.

3. Network zero range check against average plant pressure, high pressure gives automatic switch to 2 temperature control. Outside range raise transducer fault alarm.

To select next or previous

Initial Commissioning and Bitswitch Settings

The controller has 4 sets of data built in to its program for use during commissioning. These can be accessed by setting the bitswitches as shown in the table overleaf and then setting item 9 to 1234. From v0.01.3 this controller has virtual bitswitches which replace the physical bitswitches. The virtual bitswitches are set using item 966. This loads into the controller a suitable set of data for the selected type of case. Adjustments should then be made as necessary. The range over which the settings can be adjusted is also defined by the bitswitch setting.

If a JTL communications network is connected to the controller then the unit number should be set on item 1.

All 3 strategies are subject to a 5 minute delay timer. The delay is symmetrical i.e. the condition must be present/clear for 5 minutes to set/clear alarm.

7 bar transducers are alarmed at +/- 5 psi and auto zero range limited to +/- 7.5

psi. 34 bar transducers are alarmed at +/- 15 psi and auto zero range limited to

+/- 22.5 psi. Auto switch to 2 temperature control is on upper limit of range i.e.

+75 and +22.5 psi.

External Shutdown Facilities

If item 273 is set on then when input 1 is energized the expansion valve is closed. This override input is to prevent “flooding back” in the event of plant failure.

Second Case Option items press: and

From v0.01.1 firmware the controller can control and monitor a single evaporator half glass door (HGD) and well case. This option is selected on item

500.

There is also a shutdown feature which can be enabled using item 174. High suction pressure on the transducer input can also shut the pulsed expansion valve.

Where the second case option is selected the second case unit number should be set on item 501.

Defrost Initiation Strategies

The defrost strategy can be initiated in 2 fundamental ways using item 107.

Defrost initiation can be by real time clock, or by command on the JTL communications network.

Temperature Display

The temperature displayed is computed from the air on and air off temperatures. A factor is used to proportion the air off and air on temperatures. The temperature can be displayed in Celsius or Fahrenheit as selected by item 122.

The LAPI controller will drive the following JTL displays when used with the

CAB55 extension cable.

Display

LCD8

LCD9

INPUT 1

INPUT 2

Cable

CAB55

CAB55

Switch

None

3 position

Network initiated defrost can be divided into 3 groups; PREDICT, coordinated and scheduled.

This controller uses the PREDICT 1 method which monitors the PEV override operation.

PREDICT defrost requires that a JTL PREDICT defrost coordinator unit is available on the network. This unit receives requests from the PREDICT controllers and coordinates these requests so that the defrosts are organised ensuring the electrical and refrigeration requirements are met. When the controller requests a defrost the PREDICT coordinator will send out a defrost command at a suitable time. If the backup strategy is invoked the controller reverts to real time schedule.

Coordinated timed defrost requires a defrost coordinator to be present in the network. When coordinated timed request is selected then the controller requests a defrost as defined by the number of defrosts a day as set on item 69.

The defrost coordinator coordinates the defrost as required. The backup strategy can be chosen to fall to learned defrost schedule or real time backup.

DOC 03071 ISS 2 heater are energised. During pump down the PEV output is deenergised.

The display shows "dEF "

Defrost Termination selected it is energised.

The display shows "dEF".

Forced Refrigeration and Defrost not act locally.

Fan Control

The fans can be controlled in various ways.

occurred.

to 00:00.

deadband of ±0.5°C

Lighting and Night Blind Control either fans only or shutdown are selected.

High Temperature Alarms recovery.

CON10 CON9

MAINTENANCE

UNIT

The controller stays in defrost at least until the minimum defrost time, on item

145, is exceeded. If the termination temperature is reached before the minimum defrost time then the defrost heater is cycled.

Defrost Recovery

When the termination temperature or time is reached the controller enters defrost recovery. The heater is de-energised. The termination method can be chosen using item 144.

A time delay can be applied (item 49) after defrost before the PEV is reopened.

A drain down time delay can be applied (item 59) after defrost before the liquid valve is reopened. During drain down if the auxiliary heater output is

The maintenance unit can be used to force controller into a particular mode.

This is done using items 77-79. While the maintenance unit is plugged in the controller will remain in the selected mode permanently. Once the maintenance unit is unplugged the controller will revert to normal control after 30 minutes.

When the network initiated defrost strategy is selected, forced defrost will send a command to the JTL defrost scheduler to initiate a defrost and does

If item 108 is set to “fans off during defrost” then during defrost recovery the fans can be controlled depending on the evaporator temperature or time delay after defrost. If item 109 is set to 00:00 when the evaporator temperature is low enough, the fans start. There is a 5 degree deadband. If item 109 is set to a time then the fans are held off until the time delay has

If item 108 is set to “fan control during defrost”; the fans are turned off during defrost when the evaporating temperature goes above the setting on item

146. After defrost the fans are turned on when the evaporating temperature falls below the setting on item 150 or the time delay on item 109, if it is not set

If energy saving is selected using item 130, then the fans will be cycled during normal refrigeration. When the energy saving temperature, item 131, goes below the energy saving setpoint, item 132, the fans stop. There is a

The cabinet lights and night blinds can be sequenced on and off by command from the JTL network. An override switch input facility is provided which raises the blinds and turns the lights on. The lights can be switched off from the display keyswitch if item 119 is set to 1 (enabled). The lights are switched off if

The cabinet and air off temperatures are monitored continually. The temperatures are averaged over the period set on item 47. If either of the average temperatures exceeds the alarm level then an alarm is given which is shown on the display and available, for remote indication, on the JTL alarm system. High temperature alarms are cancelled during defrost and defrost

The cabinet temperature tolerance is set on item 32 and the air off tolerance on item 34. Setting either of these tolerances to 0.0°C disables the relevant alarm.

Excessive Superheat Alarms

If the measured Superheat exceeds 50°C then a sensor fault is assumed and the maximum opening of the expansion valve is reduced to 33% of the maximum allowed. When the measured Superheat is between 30 and 50°C the fault condition is activated if the suction temperature exceeds the air on temperature.

Network Shutdown and Fans Only Mode

This controller supports the JTL Network shutdown and fans only facilities.

When these facilities are enabled by item 62. If a shutdown or fans only command is received over the JTL Network, the refrigeration is stopped and alarms are disabled. The high temperature alarm sequence is initialised.

Display Controlled Shutdown

The controller can be shutdown for servicing purposes using the display switch. This feature is enabled by item 138.

The backup strategy is also invoked if the network signals that communications has failed to the defrost scheduler or if there is a fault at the defrost scheduler.

Defrost

The defrost output relay is energised during the defrost period.

The liquid solenoid is closed during defrost. The auxiliary output can be selected for fan or heater control. During defrost the fans can be stopped or the auxiliary heater energised.

A pump down delay can be applied (item 61) before the defrost/output and

Display Controlled Fans Only Mode

The controller can be put into fans only mode using the display switch. This feature is enabled by item 136.

Suction Pressure Optimisation

When used in conjunction with JTL pack control and suction optimisers this unit is normally included in the suction pressure optimiser algorithm. It can be explicitly excluded by setting item 200 to 1.

Daylight Saving

When connected to a JTL network this controller can operate by displaying daylight saving time for its time and defrost schedule. Daylight saving operation is selected by setting item 18. The connected network controller then adjusts the times automatically during the daylight saving period.

108

146

109

150

130

132

144

50

145

57

59

49

110

118

119

214

223

225

226

242

69

61

51-56

60

211

210

213

1

501

62

133

134

200

18

122

136

138

502

162

186

163

187

164

170

157

158

161

188

189

171

174

175

177

179

273

275

123

124

125

31

140

106

500

107 item

33

36-39

147

32

34

47

533

532

Function

Cabinet temperature ratio

Sensor selections

Termination sensor selection

Cabinet overtemperature tolerance

Air off over temperature tolerance

Alarm averaging time

Cabinet temperature rate (second case)

Cabinet overtemperature tolerance (second case)

Control temperature

Enable 2nd setpoint

Primary cabinet temperature setpoint

Secondary cabinet temperature setpoint

Air off temperature setpoint

Temperature control deadband

Auxiliary output selection

Enable second case

Refrigerant type

Pressure transducers zero offset

Superheat measurement method

Superheat control strategy

Superheat setpoint

Minimum superheat (pressure)

Minimum superheat (2 temperature)

Maximum valve opening (pressure)

Minimum valve opening (2 temperature)

Minimum valve opening

PEV proportional gain

PEV integral time constant

High suction pressure shutdown

Pressure transducer type

Auto zero pressure enable

Pressure display choice

PEV override input

Defrost strategy

Number of defrosts expected or required

Pump down time

Defrost schedule

Defrost schedule 12/24 hour clock

Evaporator group

Electrical supply distribution panel no

Defrost heater circuit

Defrost method

Defrost requirement priority

PREDICT Minimum time between defrosts

PREDICT Maximum time between defrosts

PREDICT override initiation

Defrost termination method

Defrost termination temp

Minimum defrost time

Defrost termination time

Drain down time

Refrigeration delay after defrost

Fan control

Temperature to turn fans off during defrost

Fan delay after defrost

Temperature to turn fans on after defrost

Fan control sensor selection

Fan control temperature setpoint

Jnet lighting control selection

Lighting contractor selection

Enable lights during shutdown

Unit number

Unit number second case

Jnet network shutdown selection

Enable plant to override temp control

Enable plant to cut off refrigeration

Exclude from suction optimisation

Daylight saving operation

Temperature display choice

Enable fans only mode from display

Enable display controlled shutdown

Enable 2nd display

ADJUSTABLE PARAMETERS

Range

20 to 80

0=off 1=on

0=off 1=on

0 to +20

0 to +30

00:30 to 03:00

20 - 100

0 - 120

1=Air off 2=cabinet temp

0=disabled 1=enabled

-30 to +10

-30 to +10

-39 to +5

0.4 to 3.0

0=off 1=Fan 2=Heater

0=Disabled 1=Enabled

3 - 9 (R type shown on MU display)

-7 to +7

1=2 temperature 2=pressure

0=SUCCEEDS, 1=SUCCEEDS with limit, 2=fixed

6.0 - 12.0

0 - 10

0 - 5

10 - 100

5 - 50

0 -50

1 - 100

1 - 250

0=disabled 1=enabled

3=-1 to 34 bar 4=-1 to 7 bar

0=disabled 1=auto 2=network

1=psi 2=bar 3=kPa

0=disable 1=enable

0=none 2=Network (learned backup)3=Time 5=PREDICT

7=Network (real time backup) 8=Coordinated (learned) 9=Coordinated (real time)

0 to 12

00:00 - 00:10

00:01 - 23:59

0=24hr 1=12hr

0=none 1=Lt 2=Ht 3=Satellite

1 to 15 panel no

1-15=circuit

0=brown phase 1=black phase 2=grey phase 3=3 phase 6=off cycle

1 to 8

2 to 8

6 to 72

0 - 100

1=Evaporator 2= Air off 3=Termination 4=Time only

0 to +20

00:00 - 00:30

00:05 to 00:59

00:00 to 00:10

00:00 to 00:10

1=run always 2=off during defrost 3=fan controlled during defrost

-12 to +20

00:00 - 00:10

-20 to +5

0=disabled 1=enabled

-30 to +8

0=disabled 1=enabled

0=n.o 1=n.c

0=disabled 1=enabled

0.1 - 899.8

0.1 - 899.8

0=disabled 1=enabled

0=off 1=on

0=disabled 1=enabled

0=include 1=exclude

0=standard time 1=daylight saving time

0=Celsius 1=Fahrenheit

0=disabled 1=enabled

O=Off 1=On

0=Disabled 1=Enabled

Bitswitch settings 21, o(CC) Frozen food (CO

2

), 1(CO) Frozen food (HFC), 2(OC) Chillers (HFC), 3(OO) Produce (HFC), where C = closed, O = open, closed = dot visible (0 to 3 is the virtual bitswitch setting on item 966)

Units hr:mn

°C

°C

°C

°C

%

%

%

K

K

K

K

K hr:mn

K psi hr:mn hr:mn hours hours

%

°C hr:mn hr:mn hr:mn hr:mn

°C hr:mn

°C

°C

LAPI

20

21

22

23

24

520

521

131

141

Item Function

30

28

240

241

TEMPERATURES

Cabinet temperature

Air on temperature

Air off temperature

Evaporator temperature

Suction line temperature

Cabinet temperature (second case)

Air on temperature (second case)

Energy saving temperature

Termination sensor temperature

CONTROL

Cabinet temperature setpoint

Effective air off setpoint

Liquid valve open %

Average liquid valve open %

154

155

156

159

166

168

169

181

182

190

Item

OTHER USEFUL ITEMS

Item

PULSED EXPANSION VALVE FUNCTIONS

Force pressure average to current reading

Suction pressure

Superheat

Auto zero offset

Force PEV opening (%)

PEV valve opening (%)

PEV status

Time since last override (hr:mn)

Duration of last override (sec)

Modifier output (%)

70

274

72

74

111

112

113

114

115

Function

MODE INPUTS & OUTPUTS

Operating mode

PEV override input state

Defrost output state

Auxiliary output state

LIGHTING

Communications lighting command

Lighting override input state

Lighting output state

Force lights on

Force lights off

Item

40

41

42

46

77

78

79

261-272

219

221

222

243

63

203

Function

DEFROST

Duration of last defrost

Time since end of last defrost

Duration of this defrost

Communications defrost command

Forced defrost

Inhibit defrost

Forced refrigeration

Learned defrost schedule

Defrost arrangement from network

Forced defrost requirement

Enable forced defrost requirement

PREDICT override average (%)

Jnet NETWORK FUNCTIONS

Network shutdown and fans only command states

Associated plant suction lin

OUTPUT STATE DIAGRAM FOR JTL CONTROLLER

MODE OF OPERATION

RL2

AUXILIARY (N/O) can be set to run always [108]

See Note 2

Heater Fans

OUTPUT & FUNCTION (See note 5)

RL3 RL4

TRIM HEATER (N/O) DEFROST (C/O)

LAPI

RL5

PULSED EXPANSION

VALVE (N/O)

Solid state output

I

G

E

R

R

E

F

R

R

M

A

L

N

O

C

L

C

Y

E

A

TI

O

N

REFRIGERATION

PUMP DOWN Adjustable time [61]

DEFROST Time/temp terminated

[57]/[50]

DRAIN DOWN Adjustable time [59]

LIQUID HOLD OFF

Adjustable time [49]

RECOVERY TIME Time/temp terminated

REFRIGERATION

OFF

OFF

ON

ON

OFF

OFF

OFF

ON

(See note 3)

OFF

OFF

OFF

OFF

TEMPERATURE

OR TIME

CONTROLLED

(See Note 6)

ON

(See note 3)

ON

ON

ON

ON

ON

ON

ON

OFF

OFF

CYCLES

ON TERMINATION

TEMP

OFF

OFF

OFF

OFF

CYCLES

ON AIR OFF TEMPERATURE

OFF

OFF

OFF

OFF

CYCLES

ON TEMPERATURE

CYCLES

ON TEMPERATURE

PLANT FAULT

UNIT SHUTDOWN

FANS ONLY SHUTDOWN

FORCED DEFROST

FORCED REFRIGERATION

INHIBIT DEFROST

OFF

OFF

OFF

ON

OFF

OFF

OFF

OFF

ON

ON

ON

ON

ON

OFF

OFF

ON

ON

ON

OFF

OFF

OFF

ON

OFF

OFF

OFF

OFF

OFF

OFF

CYCLES

ON TEMPERATURE

CYCLES

ON TEMPERATURE

NOTE 2: CAN BE SET TO OFF USING ITEM 106

NOTE 5: RL1 IS FOR LIGHTING CONTROL

NOTE 6: FANS OFF UNTIL TIME SET ON ITEM 109 REACHED.

Relay Output Rating

5A resistive.

Note

NOTE 3: CAN CYCLE ON ENERGY SAVING TEMPERATURE (SELECTED

BY ITEM 130)

The information contained in this document applies to the current version of the unit supplied with it. Full operating manuals, item number and software variation information can be obtained from your supplier or JTL Systems.

Supply Requirements

230 V ac 48-62 Hz Supply 6 VA maximum inputs 2 mA maximum

This unit conforms with the relevant EU standards when fitted in accordance with its installation instructions.

Applicable Documentation

Item Numbers

Doc No. 03396

Firmware Variations

Doc No. 03404

Connections Diagram

Doc No. 03408

Evaporator Manual

Doc No. 01923

Installation Requirements Schematic Diagram

Doc No. 03036 Doc No. 03491

SUCCEEDS® is the patented JTL algorithm for control of liquid injection into an evaporator using electronic expansion valves.

PREDICT® is the patented JTL pattern recognition algorithm for providing defrost on demand for the cabinets on a system.

03397-LAPI.wpd Issue 5 Aug 2014 Doc No. 03397 www.jtl.co.uk

JTL Systems Ltd . 41 Kingfisher Court . Hambridge Road . Newbury . Berks . RG14 5SJ Tel: (01635) 263646 Fax: (01635) 263647

JTL Help Desk Tel: 0871 315 7535