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Several temperature inputs are connected to the proces-
sor. There are either 4 or 5 thermistors (depending on the
field-installed accessories) which input temperature data
into the processor through pin terminal connector J1. See
Table 1 and Fig. 2.
Several status switches are also monitored. These switches
are connected to the processor at pin terminal connector J2.
See Fig. 3 and Table 2.
Table 1 — Pin Terminal Connector J1 Thermistor
Inputs
CONNECTOR J1
TERMINAL NO.
TEMPERATURE
INPUT
UNIT SIZE
024-030
034-074
1,2
Reset Temperature*
T10
14,15
Saturated Condensing
Temp., Circuit 2
Fixed
Resistor†
T4
16,17
Saturated Condensing
Temp., Circuit 1
Fixed
Resistor†
T3
18,19
Return-Air
Temperature
T2
20,21
Leaving-Air
Temperature
T1
T — Thermistor
*If equipped with accessory temperature reset package.
†The fixed resistor has a resistance value of 1200 ohms ± 5%.
NOTE: Terminal numbers 3-13 are not used on these units.
Table 2 — Pin Terminal Connector J2 Status Switch
Inputs
CONNECTOR J2
TERMINAL NO.
STATUS SWITCH
UNIT SIZE
024-030
034-074
1,2
Oil Pressure,
Circuit 2
Jumpered
3,4
Oil Pressure,
Circuit 1
Jumpered
7,8
Loss Of Charge,
Circuit 2
Jumpered
LPS2
9,10
Loss of Charge,
Circuit 1
Jumpered
LPS1
13,14
Economizer
Changeover
ECR
EC
15,20
Compressor Fault
Signal
CR2
15,24
Compressor Fault
Signal
CR1
LEGEND
CR
— Control Relay
EC
— Enthalpy Control
ECR — Enthalpy Control Relay
LPS — Low-Pressure Switch
NOTE: Terminal numbers 5, 6, 11, 12, 16-19, and 21-23 are not used
on these units.
LEGEND
CR
— Control Relay
EC
— Enthalpy Control
ECR — Enthalpy Control Relay
LPS — Low-Pressure Switch
Fig. 3 — Pin Terminal Connector J2 Status Switch
Inputs
LEGEND
R
—
Resistor
T
—
Thermistor
Field Wiring
Accessory
Fig. 2 — Pin Terminal Connector J1 Thermistor
Inputs
3