Technical Guide

Subject to change without notice. Printed in U.S.A. 505428-YTG-R-1114
Copyright © 2014 by Johnson Controls, Inc. All rights reserved. Supersedes: 505428-YTG-Q-0314
York International Corporation
5005 York Drive
Norman, OK 73069
Typical Field Wiring Diagram - Twin NC090 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.
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