User Manual

5
Terminal Descriptions
G Fan
Rc Cool transformer
Rh Heat transformer
O/B Heat pump reversing valve
Y/Y1 Used for first stage of conventional A/C or first
stage of heat pump compressor
Y2 Used for second stage of conventional A/C or
second stage of heat pump compressor
W W1, W2: Used for 1 -- 2 stages of conventional
heat or 1 -- 2 stages of electric auxiliary heat (3
stages -- Intelligent heat staging configuration)
C 24VAC common
ACC Accessory (+/--): Used for dehumidifiers,
humidifiers, ventilators, HRVs or ERVs
This thermostat is designed for 24VAC with a 2A maximum current.
Do not connect it to line (high) voltage or millivolt systems.