Honeywell Design and Application User Manual

Section 17 - Retrofit and Upgrades
187 Honeywell Economizers 63-8594-02
After: W973 with W7220 Economizer Module
There are many older controllers in field that may be replaced with new controllers and new
economizers. Call your local distributor or the Honeywell Commercial controls hotline if you have
questions that are not addressed in this application guide.
ROOF TOP UNIT
Y1O
Y2O
Y1I
Y2I
OCC
24 VAC
E-GND
Y1
G
W2
W1
Y2
O/B
OCC
W7220 ECONOMIZER CONTROLLER MODULE
THERMOSTAT
CO2
SENSOR
2-10 VDC
(OPTIONAL)
MAT
MAT
OAT
OAT
C R
R(+)
C(-)
M32650D
IAQ (2-10V)
IAQ COM
IAQ 24V
ACT (2-10V)
ACT COM
ACT 24V
3
1
2
OAT TEMP
SENSOR
20K NTC
MS3103J
OR MS3105J
1
1
MA TEMP
SENSOR
20K NTC
S-BUS
4
5
S-BUS
AUX1-0
AUX2-I
NOTE THAT THE 20K NTC SENSOR CAN BE MOUNTED IN THE OAT TERMINALS ONLY IN THIS CONFIGURATION.
WHEN USING A HEAT PUMP THERMOSTAT, THERMOSTAT TERMINALS MAY DIFFER: W1 MAY BE LABELED O
OR B AND W2 MAY BE LABELED W.
WHEN USING A HEAT PUMP WITH DEFROST FEEDBACK, ADD AN ISOLATION RELAY BETWEEN O AND C.
2
2
3
3
1K1
1K1

Honeywell Design and Application Specifications

General

Brand	Honeywell
Model	Design and Application
Category	Controller
Language	English