Table 11: Unit Operation
CXM Controls
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
Ä
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.
CXM Thermostat Details
Thermostat Compatibility - Most all heat pump thermostats
can be used with the CXM control.
However Heat/Cool
stats are NOT compatible with the CXM.
Anticipation Leakage Current - Maximum leakage current
for "Y" is 50 mA and for "W" is 20mA. Triacs can be used
if leakage current is less than above. Thermostats with
anticipators can be used if anticipation current is less than
that speci
Ä
ed above.
Thermostat Signals -
• "Y" and "W" have a 1 second recognition time when
being activated or being removed.
• "O" and "G" are direct pass through signals but are
monitored by the micro processor.
• "R" and "C" are from the transformer.
• "AL1" and "AL2" originate from the alarm relay.
• "A" is paralleled with the compressor output for use
with well water solenoid valves.
• The "Y" 1/4" quick connect is a connection point to the
"Y" input terminal P1 for factory use. This "Y" terminal
can be used to drive panel mounted relays such as the
loop pump relay.
Table 12: Nominal resistance at
various temperatures
Temp
(°C)
Temp
(°F)
Temp
(°C)
Temp
(°F)
Resistance
(kOhm)
Resistance
(kOhm)
R e s i d e n t i a l S p l i t U n i t s - 6 0 H z P u r o n
®
R e v. : 6 D e c . , 2 0 1 1
40
T-stat signal
GT-PX
Variable Speed Air Handler
G
Fan only
G, Y or Y1
Stage 1 heating
1
G, Y1, Y2
Stage 2 heating
1
G, Y1, Y2, W
Stage 3 heating
1
G, W
Emergency heat
G, Y or Y1, O
Stage 1 cooling
2
G, Y1, Y2, O
Stage 2 cooling
2
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
