Johnson Controls
187
Section 9: Service and troubleshooting
Form 150.72-ICOM6
Issue date: 12/19/2023
9
S Y S 1 S U C T P R J 7 - 1 0
2 . 1 V D C = 8 1 P S I G
This example indicates that the system 1 suction pres-
sure input is connected to plug 7 – pin 10 (J7-10) on the
I/O board. It indicates that the voltage is 2.1 VDC which
corresponds to 81 psig (5.6 bar) suction pressure.
The digital inputs will display the input connection and
ON/OFF status such as:
F L O W S W / R E M S T A R T
J
13
- 5 I S O
N
This indicates that the flow switch/remote start input is
connected to plug 13- pin 5 (J13-5) on the microboard,
and is ON (ON = +30 VDC unregulated input, OFF =
0VDC input on digital inputs).
Control inputs/outputs
through
are a quick
reference list providing the connection points and a
description of the inputs and outputs respectively. All
input and output connections pertain to the connections
at the microboard.
Table 27:
I/O Digital Inputs
J13-2
Unit ON/OFF Switch
J13-3
Load Limit Stage 2 on 3, 5 & 6 Comp. Units
J13-4
Load Limit Stage 1
J13-5
Flow Switch and Remote Start/Stop
J13-6
Spare
J13-7
Single System Select
(Jumper = Single Sys, No Jumper = Two Sys)
J13-8
CR1
(Sys 1 Motor Protector/High Pressure Cutout)
J13-10
CR2
(Sys 2 Motor Protector/High Pressure Cutout)
Table 28:
I/O Digital Outputs
TB7-2
SYS 1 Compressor 1
TB7-3
SYS 1 Liquid Line Solenoid Valve
TB7-4
SYS 1 Compressor 2
TB7-5
SYS 1 Compressor 3
TB7-7
SYS 1 Hot Gas Bypass Valve
TB10-2
SYS 2 Compressor 1
TB10-3
SYS 2 Liquid Line Solenoid Valve
TB10-4
SYS 2 Compressor 2
TB10-5
SYS 2 Compressor 3
TB7-8
SYS 1 Condenser Fan Output 1
TB7-9
SYS 1 Condenser Fan Output 2
TB7-10
SYS 1 Condenser Fan Output 3
TB10-8
SYS 2 Condenser Fan Output 1
TB10-9
SYS 2 Condenser Fan Output 2
TB10-10
SYS 2 Condenser Fan Output 3
TB8-2
Evaporator Heater
TB8-3
SYS 1 Alarm
TB9-2
SYS 2 Alarm
TB8-6 & 7
Evaporator Pump Starter
TB10-7
SYS 2 Hot Gas Bypass Valve
Table 29:
I/O Analog Inputs
J7-10
SYS 1 Suction Transducer
-or-
SYS 1 Low Pressure Switch
J11-12
Unit Type: Chiller = NO Jumper J11-12 to +24
VDC
YCUL Condensing Unit = Jumper J11-12 to +24
VDC (Do NOT Use)
J7-11
SYS 1 Discharge Pressure Transducer (Optional)
J6-9
Ambient Air Temp. Sensor
J6-7
Leaving Chilled Liquid Temp. Sensor
J6-8
Return Chilled Liquid Temp. Sensor
J9-10
SYS 2 Suction Pressure Transducer
-or-
SYS 2 Low Pressure Switch
J9-11
SYS 2 Discharge Pressure Transducer
(Optional)
J7-12
Unit/SYS 1 Voltage
J9-12
SYS 2 Voltage
J11-11
Remote Temperature Reset
Table 30:
I/O Analog Outputs
N/A
Not Applicable
