Honeywell PRESTIGE THX9321 System Installation Manual page 14

System Installation Guide
Prestige THX9321 or EIM:
Using universal relays to control heating or cooling
Powering universal relay with system
transformer (THX9321 shown)
Transformer
120 24
VAC
VAC
HEAT STAGE 3 or
COOL STAGE 3 or
COOL STAGE 4
3
1
U1/U2/U3 terminals are normally open dry contacts when set up for a stage of heating or cooling.
2
You must install a field jumper if the stage of heating or cooling is powered by system transformer. Do NOT install a field
jumper if the stage of heating has its own transformer.
3
U1/U2/U3 terminals are assigned to a stage of heating or cooling in the Installer Setup. Options are:
• Heat -- Stage 3 (last stage of heating) -- ISU 2100, 2140, or 2170
• Cool: Stage 3 -- ISU 2080
• Cool: Stage 4 -- ISU 2090
• Geothermal radiant heat: Stage 1 -- (see wiring guide on pages 12-13)
• Geothermal radiant heat: Stage 2 -- (see wiring guide on pages 12-13)
69-2490—03
69-2490_B.indd 14
C
R
C
Rc
R
2
U1
1
U1
U2
1
U2
MCR32952
Powering universal relay with separate
heating transformer (THX9321 shown)
Transformer
120
24
VAC VAC
R
Transformer
120
24
C
VAC VAC
14
C
R
C
Rc
R
2
U1
1
HEAT STAGE 3
U1
U2
3
1
U2
MCR32953
7/13/2011 1:41:57 PM