Honeywell PRESTIGE THX9321 System Installation Manual page 11

EIM wiring guide — heat pump systems
Typical wiring of a heat pump system with up to four-stage heat and two-stage
cool with one transformer.
EIM
POWER
STATUS
LEDS
1
See guides on following pages for thermostat wiring and geothermal radiant heat wiring.
2
Wire a maximum of 2 sensors using the S1 and S2 terminals. See ISU 5000-6190 for options.
3
L/A terminal sends continuous output when thermostat is set to EM HEAT mode, except when set up for Economizer
or TOD. See Economizer wiring section.
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TO THERMOSTAT
HEAT
COOL
FAN
U1
U2
U3
SENSORS
THX9321/9421 Prestige
O/B
HEAT PUMP
O/B
AUX1
AUX1
AUX2
AUX2
L/A
3
L/A
1
2
CONNECT OPTIONAL
S1 AND S2 TERMINALS
2
11
IAQ and RF EIM
®
CHANGEOVER VALVE
BACKUP HEAT
STAGE 1
BACKUP HEAT
STAGE 2
COMPRESSOR
Y
STAGE 1
COMPRESSOR
Y2
STAGE 2
G
FAN RELAY
COMPRESSOR
MONITOR OR
3
ZONE PANEL
JUMPERS
AIR HANDLER
TRANSFORMER
R
24 120
C
VAC VAC
SENSORS TO
(MAX. 2 SENSORS)
MCR32946
69-2490—03
7/13/2011 1:41:54 PM