Wiring Iaq Equipment Or A Heat/Cool Stage To The U1 Terminals - Honeywell TH8321 Product Data

VISIONPRO® 8000 SMART THERMOSTAT

Wiring IAQ Equipment or a Heat/Cool Stage to the U1 Terminals

To Thermostat
"U" terminals can be used for humidification, dehumidification, ventilation or a stage of heating/cooling.
THERMOSTAT
C
K
R
C
R
POWERED
U1
HUMIDIFIER,
DEHUMIDIFIER
U1
OR VENTILATOR
Fig. 225. Wiring a powered humidifier, dehumidifier, or
ventilator.
THERMOSTAT
C
K
R
C
R
1
U1
OR
U1
Fig. 226. Dehumidification with low speed fan using a
variable speed blower.
1Wire the thermostat U1 contact to the low speed fan for
dehumidification control at the equipment. The thermo-
stat relay can be set to normally open or normally closed
in the thermostat installer setup.
Normally open, dry contacts
Normally closed, dry contacts
33-00096—04
SYSTEM
TRANSFORMER
C
24 120
VAC VAC
R
HUM, DEHUM OR
VENT
TRANSFORMER
24 120
VAC VAC
SYSTEM
TRANSFORMER
C
24 120
VAC VAC
R
FIELD INSTALL JUMPER
BETWEEN R AND U1
DEHUMIDIFICATION
WITH LOW SPEED FAN
THERMOSTAT
C
K
R
C
FIELD INSTALL JUMPER
R
BETWEEN R AND U1
U1
NON-POWERED
HUMIDIFIER,
U1
DEHUMIDIFIER
OR VENTILATOR
Fig. 227. Wiring a non-powered humidifier, dehumidifier,
or ventilator.
THERMOSTAT
C
K
R
C
R
1
2
U1
U1
Fig. 228. Wiring a heat or cool stage to U1.
1U1 terminals 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 system transformer. Do NOT install
a field jumper if the stage of heating has its own trans-
former.
86
SYSTEM
TRANSFORMER
C
24 120
VAC VAC
R
TRANSFORMER
C
24 120
VAC VAC
R
HEAT STAGE 3, COOL
STAGE 3, BACKUP HEAT
STAGE 2 FOR HEAT
PUMPS, OR GEOTHERMAL
RADIANT HEAT