Mitsubishi Electric TRANE NTXAMT12A112AA Service Manual page 46

Error Abnormal point and detection method
Code
P6 Freezing/overheating protection is working
1. Freezing protection (Cooling mode) The unit is in six-mi-
nute resume prevention mode if pipe <liquid or condens-
er/evaporator> temperature stays under -15˚C[5˚F] for
three minutes after the compressor started. Abnormal if
it stays under -15˚C[5˚F] for three minutes again within 16
minutes after six-minute resume prevention mode.
2. Overheating protection (Heating mode) The units is in
six-minute resume prevention mode if pipe <Liquid or
condenser / evaporator>temperature is detected as over
70˚C[158˚F] after the compressor started. Abnormal if the
temperature of over 70˚C[158˚F] is detected again within
10 minutes after six-minute resume prevention mode.
Specifications are subject to change without notice.
NTXAMT12, 18, 24, 30, 36A112AA
Cause
(Cooling or drying mode)
1. Clogged filter (reduced airflow)
2. Short cycle of air path
3. Low-load (low temperature)
operation beyond the tolerance
range
4. 4 Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is de-
fective.
5. Defective outdoor fan control
6. Overcharge of refrigerant
7. Defective refrigerant circuit
(clogs)
(Heating mode)
1. Clogged filter (reduced airflow)
2. Short cycle of air path
3. Over-load (high temperature)
operation beyond the tolerance
range
4. Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is de-
fective.
5. Defective outdoor fan control
6. Overcharge of refrigerant
7. 7 Defective refrigerant circuit
(clogs)
8. Bypass circuit of outdoor unit is
defective
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Countermeasure
(Cooling or drying mode)
1. Check clogging of the filter
2. Remove shields
4. Refer to 12-8. DC Fan motor (FAN MOTOR/
INDOOR CONTROLLER BOARD)
5. Check outdoor fan motor
6~7. Check operating condition of refrigerant
circuit.
(Heating mode)
1. Check clogs of the filter
2. Remove shields
4. Refer to 12-8. DC Fan motor (FAN MOTOR/
INDOOR CONTROLLER BOARD)
5. Check outdoor fan motor
6~8. Check operating condition of refrigerant
circuit