Honeywell Prestige THX9321 System Installation Manual page 12

System /nstallation Guide
ElM wiring guide -- geothermal radiant heat
Typical wiring for geothermal radiant heat, geothermal forced=air, and backup
heat with one transformer.
STATUS =
LEDS
ElM
TO THERMOSTAT
HEATPUMP
-_OWER = = ----4_---- _ OZB--
HEAT E:3 _-----41----- _ AUX1
COOL _ _---II---- _ AUX2
FAN _ -----tl---- _ Y
U2 _ -'_F---- _ G n
__ US _ ----4_'--" _ LiA_
u3U3
Corq
OPTIONAL _ RH
JUMPER_ RC
R
C
JUMPERS
$2 m
SENSORS S2 m
S1
S1_
O__CHANGEOVER VALVE F
___J d _
[
STAGE I
BACKUP HEAT L
STAGE--.-----Z-- F
-- I __y
LiCOMPRESSOR MONITOR--
HEAT STAGE 1 J "
AIR HANDLER
TRANSFORMER
CONNECT OPTtONAL
SENSORS TO
$1 AND S2 TERMINALS
(MAX. 2 SENSORS)
MCR32947
U1, U2 or U3 terminals must be used for geothermal radiantheat (ISU 2010).Thermostat allows2 stagesof radiant heat--
geothermal(stage 1) and boiler (stage2).
A "U"terminals are normallyopen dry contacts when set up for geothermalradiant heat.You must install a field jumper if radiant
heat is powered by system transformer.Do NOTinstall a field jumper if radiant heat has its own transformer.
A L/A terminal sends continuousoutputwhen thermostat is set to EM HEAT modeexceptwhen set up for Economizeror TOD.
See Economizerwiring section.
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