Installer Setup 4 - EWC Controls EWT-3102 User Manual

Table 2. Terminal Designation Descriptions.
Terminal Designation
RC (see Note 1)
R (see Note 1)
C (see Note 2)
W
Y
G
Y2
W2
O/B (see Note 3)
AUX
E
L (see note 4)
S1, S2
NOTES:
1. When used in a single-transformer system, leave metal jumper wire in place between RC and R. If
used on a two-transformer system, remove metal jumper wire between RC and R.
2. Common wire is optional when thermostat is used with batteries.
3. If thermostat is configured for a heat pump system in the Installer Setup, configure changeover valve
for cool (O-factory setting) or heat (B).
4. L terminal is an input (system monitor) when the System mode is in the Heat, Off, Cool or Auto
position. L terminal is a 24 VAC output when System mode is Emergency Heat. Must connect the 24
VAC Common when using the L terminal. See LCD indications on page 90.
EWT-3102 / EWT-3103 Touchscreen Programmable Thermostat
Power for cooling--connect to secondary side of cooling system
Power for heating--connect to secondary side of heating system
Common wire from secondary side of cooling system transformer
Compressor contactor
Second stage cooling
Second stage heat relay
Changeover valve for heat pump systems
Auxiliary heat relay for heat pump systems
Emergency heat relay for heat pump systems
Equipment monitor for heat pump systems
Optional outdoor or indoor remote sensor
Description
transformer
transformer
Heat relay
Fan relay
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