Trane ReliaTel Diagnostic Manual page 75

Table 22. Thermostat signals
R
Y1
Y2
G
W1
W2
Heat pump only:
X2
O
T
Table 23. Conventional thermostat – Gas/ Electric, Electric Heat:
Input/connection
G (fan)
Y1 (compressor 1 or economizer)
Y2 (compressor 2 or compressor 1 while
economizing)
W1 (gas / electric heat first stage)
W2 (gas / electric heat 2nd stage)
Table 24. Conventional thermostat – Heat Pump
Input/connection
Cooling mode:
G (fan)
O (reversing valve during cooling)
Y1 + O (first stage cooling)
Y1 + Y2 + O (2
Heating mode:
G (fan)
Y1 (both compressors 1st stage heat)
Y2 (during heating – nothing happens)
W2 (electric heat 2nd stage)
X2 (electric heat only)
1. For units configured with 2-Step Mechanical Heating (Odyssey Independent Circuit
T: (provides heat anticipation signal for those mechanical thermostats that use this feature. If the
thermostat used does not have a "T" terminal, disregard this terminal.
Unoccupied mode: If the thermostat being used is programmable, it will have its own strategy
for unoccupied mode and will control the unit directly. If a mechanical thermostat is being used,
RT-SVD03G-EN
Operation with a Conventional Thermostat (Constant Volume)
24VAC power to thermostat
Call for compressor 1 or first stage cooling
Call for compressor 2 or 2
Call for supply fan
Call for heat 1 (for modulating gas, see
Call for heat 2
Call for emergency heat
Switchover valve On = cooling, Off = heating
Bias for heat anticipation for those mechanical thermostats
that use this function
nd
stage cool)
Heat Pump), Y1 will correspond to a request for Compressor 1 operation and Y2 will
correspond to a request for Compressor 2 operation.
nd
stage cooling
Figure 50, p. 77)
Function when energized:
Fan runs continuously except during
unoccupied mode (see next page)
Compressor #1 runs or economizer
operates
Compressor #2 also runs, or
#1compressor runs while economizing
st
1 stage heat
nd
2 stage heat (if available)
Function when energized
Fan runs continuously except during
unoccupied mode (see next page)
Reversing valve in cool mode
Compressor #1 runs or economizer
operates
Compressor #2 also runs, or #1
compressor runs while economizing.
Fan runs continuously except during
unoccupied mode (see below)
1.
Both compressors run
1.
No change
2nd stage (electric) heat
Electric heat only – no compressors
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