THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ WITH EIM
68-0311—02
150
Fig. 345. Connecting a stage of heating or cooling to a universal relay (U1, U2, U3).
1U1, U2, and U3 are normally open dry contacts when set up for a stage of heating or cooling.
2You must install a field jumper if the stage of heating or cooling is powered by the system transformer. Do NOT install a field
jumper if the stage of heating has its own transformer.
1
2
U3
U3
U2
U2
U1
U1
120
VAC
24
VAC
24
VAC
HEAT STAGE 3,
COOL STAGE 3,
COOL STAGE 4 OR
GEOTHERMAL
RADIANT HEAT
RH
RC
R
C
TRANSFORMER