Technical Guide

505428-YTG-R-1114
126 Johnson Controls Unitary Products
Typical Field Wiring Diagram - Twin NC120 thru 240 Evaporator Units with 4-Pipe Condenser Unit
NOTE: On non NC/ND Evaporator models, isolation relays must be installed to avoid overloading on 75 VA transformers on the
condensing unit.
NC120 - 240 Liquid Line Solenoid Wiring NOTE: Refer to Evaporator unit wiring diagram for control of
liquid line solenoid valve.
R C
Y1
G W1 R C
Y1
G W1
THERMOSTAT
SINGLE STAGE COOLING
TWO STAGE HEATING
W2 W2
THERMOSTAT
SINGLE STAGE COOLING
TWO STAGE HEATING
X X
219 / Y
218 / BR
1LLS
VALVE SYS 2
BLK
BLK
C O I L