Troubleshooting - Trane 2GN Series Installer's Manual

TROUBLESHOOTING

Standard Microprocessor Controls
To check the unit control board for proper operation:
1. Disconnect thermostat wires at the control board.
2. Jumper the desired test input (Y1, Y2, W, O or G) to the
R terminal to simulate a thermostat signal.
3. If control functions properly:
• Check for thermostat and fi eld control wiring (use
the diagnostic inputs mode).
4. If control responds improperly:
• Ensure that component being controlled is
functioning (compressor, blower, reversing valve,
etc.).
• Ensure that wiring from control to the component is
functioning (refer to the LED Defi nition table below
and use the diagnostic outputs mode).
• If steps above check properly, replace unit control.
LED Defi nitions and Diagnostics
Standard Microprocessor
NORMAL
LED
DISPLAY MODE
FIELD SELECTION
DIPS
SW2-
SW2-
SW2-
DRAIN PAN
DRAIN OVERFLOW
LOCKOUT
FD THERMISTOR
(LOOP <15º F,
WATER FLOW
WELL<30ºF)
LOCKOUT
HIGH
HIGH PRESSURE
>600 PSI LOCKOUT
PRESSURE
LOW LOW PRESSURE <40
PRESSURE PSI LOCKOUT
ECM2 RPM <100
AIRFLOW
RPM
MICROPROCESSOR
STATUS
MALFUNCTION
HWL THERMISTOR
DHW LIMIT
>130ºF
DHW PUMP
DHW OFF
SWITCH OFF
18-GL07D1-4
CURRENT FAULT
STATUS
1 ON SW2- 1 OFF
6 ON SW2- 6 ON
7 ON SW2- 7 ON
DRAIN PAN
OVERFLOW
FD THERMISTOR
(LOOP <15º F,
WELL<30ºF)
HIGH PRESSURE
>600
LOW PRESSURE <40
ECM2 RPM <100
RPM
NOT USED
HWL THERMISTOR
>130°F
DHW PUMP
SWITCH OFF
Refrigerant Systems
To maintain sealed circuit integrity, do not install service
gauges unless unit operation appears abnormal. Compare
the change in temperature on the air side as well as the
water side to the Operating Parameters tables. If the unit's
performance is not within the ranges listed, and the airfl ow and
water fl ow are known to be correct, gauges should then be
installed and superheat and subcooling numbers calculated. If
superheat and subcooling are outside recommended ranges,
an adjustment to the refrigerant charge may be necessary.
Notes: Refrigerant tests must be made with hot water
generator turned "OFF". Verify that air and water fl ow
rates are at proper levels before servicing the refrigerant
circuit.
DIAGNOSTIC MODES
INPUTS OUTPUTS 1
SW2- 1 NA SW2-
SW2- 6 OFF SW2-
SW2- 7 ON SW2-
COMPRESSOR
Y1
(ON OR LOW)
COMPRESSOR
Y2
(ON OR HIGH)
O REVERSING VALVE
G
W DHW PUMP
SL1 LOOP PUMP 1
NOT USED LOOP PUMP 2
–
2GN SPLIT INSTALLER'S GUIDE
OUTPUTS 2
1 NA SW2-
1 NA
6 ON SW2-
6 OFF
7 OFF SW2- 7 OFF
BLOWER
LOW
BLOWER
MEDIUM
BLOWER
HIGH
FAN AUX HEAT 1
AUX HEAT 2
AUX HEAT 3
AUX HEAT 4
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