Economizer Module Wiring Diagrams; Wiring A W7220 Economizer Module For A Heat Pump System; Wiring A W7220 Economizer Module For A Conventional System - Honeywell THX9321 Prestige 2.0 Product Data

Economizer Module Wiring Diagrams

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.
Fig. 347. Wiring a W7220 Economizer Module for a conventional system.
1 "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).
2 Terminal AUX 2 is present only on the Equipment Interface Module.
3 Connect the changeover valve from the roof top unit to the normally open contacts of an isolation relay to prevent feedback into
the economizer module during defrost. If this is not done when the system goes into defrost, it will change the economizer into
cooling mode due to the feedback and open the outside damper while in heating mode.
W7220 Economizer Module
(See wiring guidelines provided with the product)
AUX2-I
OCC
E-GND
AUX1-O
Y2-I
Y2-O
Y1-I
Y1-O
C
R
Transformer
Fig. 346. Wiring a W7220 Economizer Module for a heat pump system.
W7220 Economizer Module
(See wiring guidelines provided with the product)
AUX2-I
OCC
E-GND
AUX1-O
Y2-I
Y2-O
Y1-I
Y1-O
C
R
Transformer
®
THX9321 PRESTIGE
O/B
3
3 1
O/B L/A
1
R
120 24
VAC C
VAC
A
1
R
120 24
C
VAC VAC
151
2.0 AND THX9421 PRESTIGE
Rooftop Unit
Y1 Y2 AUX AUX 2 G
Y Y2 AUX AUX 2 G
2
Thermostat/EIM
MCR34808
Rooftop Unit
Y1 Y2 W1 W2 G
Y Y2 W W2 G
Thermostat/EIM
MCR34810
®
IAQ WITH EIM
68-0311—02