System Installation Guide
16
69-2490—05
Economizer Module wiring guides
Typical wiring of a W7220 Economizer Module for a heat pump system, using a
Prestige THX9321 thermostat or Equipment Interface Module.
Typical wiring of a W7220 Economizer Module for a conventional system, using a
Prestige THX9321 thermostat or Equipment Interface Module.
1
2
“A” or “L/A” terminal must be configured for Economizer in the installer setup (ISU 2220).
These terminals are powered by the cooling transformer (Rc terminal).
Terminal AUX 2 is present only on the Equipment Interface Module.
120
VAC
N
Y1
Y2
W1
W2
G
24
VAC
SD-O/B
OCC
E-GND
AUX
Y2I
Y2O
Y1I
Y1O
C
R
Rooftop Unit
Transformer
A
Y
Y2
W
W2
G
Thermostat/EIM
R
C
W7220 Economizer Module
(See wiring guidelines provided with the product)
1
MCR32955A
120
VAC
O/B
N
Y1
Y2
AUX AUX 2
G
24
VAC
SD-O/B
OCC
E-GND
AUX
Y2I
Y2O
Y1I
Y1O
C
R
Rooftop Unit
Transformer
O/B
L/A
Y
Y2
AUX AUX 2
G
Thermostat/EIM
R
C
W7220 Economizer Module
(See wiring guidelines provided with the product)
2
1
MCR32959A
