Unit Operation - Carrier GT-G User Manual

Carrier
Diagnostic Features
The LED on the CXM board advises the technician of
the current status of the CXM control. The LED can
display either the current CXM mode or the last fault in
memory if in test mode. If there is no fault in memory,
the LED will fl ash Code 1 (when in test mode).
CXM Control Start-up Operation
The control will not operate until all inputs and safety
controls are checked for normal conditions. The
compressor will have a 5 minute anti-short cycle delay
at power-up. The fi rst time after power-up that there is a
call for compressor, the compressor will follow a 5 to 80
second random start delay. After the random start delay
and anti-short cycle delay, the compressor relay will
be energized. On all subsequent compressor calls, the
random start delay is omitted.

Unit Operation

T-stat signal
G
G, Y or Y1
G, Y1, Y2
G, Y1, Y2, W
G, W
G, Y or Y1, O
G, Y1, Y2, O
1 Stage 1 = 1st stage compressor, 1st stage fan operation
Stage 2 = 2nd stage compressor, 2nd stage fan operation
Stage 3 = 2nd stage compressor, auxiliary electric heat, 2nd
or 3rd stage fan operation (depending on fan settings)
2 Stage 1 = 1st stage compressor, 1st stage fan operation, reversing valve
Stage 2 = 2nd stage compressor, 2nd stage fan operation, reversing valve
3 Stage 1 = compressor, 1st stage fan operation
Stage 2 = compressor, 2nd stage fan operation
Stage 3 = compressor, auxiliary electric heat, 2nd or 3rd stage fan operation (depending on fan settings)
4 Stage 1 = compressor, 1st stage fan operation, reversing valve
Stage 2 = compressor, 2nd stage fan operation, reversing valve
5 Stage 1 = compressor, fan
Stage 2 = compressor, auxiliary electric heat, fan
6 Cooling = compressor, fan, reversing valve
42
Carrier Indoor & Outdoor Split Geothermal Heat Pumps - Rev.: 08/10/05
GT-PX TTS
Variable Speed
Air Handler
Fan only
1
Stage 1 heating
1
Stage 2 heating
1
Stage 3 heating
Emergency heat
2
Stage 1 cooling
2
Stage 2 cooling
GT-GS / GT-S GSS/PDW
Variable Speed
Air Handler
Fan only
3
Stage 1 heating
3
Stage 2 heating
3
Stage 3 heating
Emergency heat
4
Stage 1 cooling
4
Stage 2 cooling
CXM Controls
GT-GS / GT-S GSS/PDW
PSC Air Handler
Fan only
5
Stage 1 heating
5
Stage 2 heating
N/A
Emergency heat
6
Cooling
N/A