Terminal Designations - Lutron Electronics 33-00155EFS Installation Manual

Conventional System
Terminal
Common wire from secondary side of
C
cooling transformer (if 2 transformers).
Rc* Cooling power.
R* Heating power.
W Heat Stage 1
W2 Heat Stage 2
Y Compressor Stage 1
Y2 Compressor Stage 2
G Fan Relay
Connect to Economizer Module or
A
Lighting Panel (TOD).
Universal relay for humidification,
U1 / U1 dehumidification, ventilation, or a stage of
heating/cooling.
Universal input for a wired indoor, outdoor
S1 / S1
or discharge sensor.
K** Connect to K on Wire Saver module.
*
Remove factory installed jumper for two transformer systems.
**
The THP9045A1023 Wire Saver module is used on heat/cool systems when you only have four wires at the thermostat and you
need a fifth wire for a common wire. Use the K terminal in place of the Y and G terminals on conventional or heat pump systems to
provide control of the fan and the compressor through a single wire—the unused wire then becomes your common wire. See THP9045
instructions for more information.
POWERED HUMIDIFIER, DEHUMIDIFIER OR VENTILATOR
THERMOSTAT
C
K
R
C
R
POWERED
U1
HUMIDIFIER,
DEHUMIDIFIER
U1
OR VENTILATOR
DEHUMIDIFICATION WITH LOW SPEED FAN
THERMOSTAT
C
K
R
C
FIELD INSTALL JUMPER
R
BETWEEN R AND U1
1
U1
OR
DEHUMIDIFICATION
U1
WITH LOW SPEED FAN
1
Wire the thermostat universal relay to the low speed fan
for dehumidification control at the equipment. The
thermostat relay can be set to normally open or
normally closed in the thermostat installer setup.
Normally open, dry contacts
Normally closed, dry contacts

Terminal Designations

Description
SYSTEM
TRANSFORMER
C
24 120
VAC VAC
R
HUM, DEHUM OR
VENT TRANSFORM-
ER
24 120
VAC VAC
SYSTEM
TRANSFORMER
C
24 120
VAC VAC
R
Terminal
Common wire from secondary side of
C
cooling transformer.
Rc Cooling power.
R Heating power.
O/B Changeover valve for heat pumps.
AUX-E Backup Heat/Emergency Heat
Y Compressor Stage 1
Y2 Compressor Stage 2
G Fan Relay
Connect to Compressor Monitor, Zone
L/A Panel, Economizer Module or Lighting
Panel (TOD).
Universal relay for humidification,
U1 / U1 dehumidification, ventilation, or a stage of
heating/cooling.
Universal input for a wired indoor, outdoor
S1 / S1
or discharge sensor.
K** Connect to K on Wire Saver module.
NON-POWERED HUMIDIFIER, DEHUMIDIFIER OR VENTILATOR
THERMOSTAT
C
K
R
C
FIELD INSTALL JUMPER
R
BETWEEN R AND U1
U1
NON-POWERED
HUMIDIFIER,
U1
DEHUMIDIFIER
OR VENTILATOR
CONNECTING A HEAT OR COOL STAGE TO U1
THERMOSTAT
C
K
R
C
R
1
2
U1
STAGE 3, BACKUP HEAT
U1
PUMPS, OR GEOTHERMAL
1
U1 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.
4
Heat Pump
Description
SYSTEM
TRANSFORMER
C
24 120
VAC VAC
R
TRANSFORMER
C
24 120
VAC VAC
R
HEAT STAGE 3, COOL
STAGE 2 FOR HEAT
RADIANT HEAT