Mitsubishi Electric PUMY-P100VHMB Service Manual page 43

Display
Abnormal point and detecting method
High discharge/compressor temperature
1102
Abnormal if discharge/compressor temperature
thermistor (TH4) exceeds 125
continuously for 5 minutes.
Abnormal if pressure detected by high-pressure
sensor and converted to saturation temperature
exceeds 40 during defrosting and
discharge/compressor temperature thermistor
(TH4) exceeds 110 .
1300 Low pressure (63L operated)
Abnormal if 63L is operated (under- 0.03MPa)
during compressor operation.
63L: Low-pressure switch
1302 (1) High pressure (High-pressure switch
63H operated)
Abnormal if high-pressure switch 63H operated
( ) during compressor operation.
4.15 MPa
63H: High-pressure switch
(2) High pressure
(High - pressure sensor 63HS detect)
Abnormal if high-pressure sensor detects
4.31MPa or more (or over 4.15MPa
for 3 minutes) during the compressor
operation.
1500
Superheat due to low discharge temperature
Abnormal if discharge superheat is
continuously detected less than or equal to -15
even though linear expansion valve has
minimum open pulse after compressor starts
operating for 10 minutes.
Over-heated compressor operation
caused by shortage of refrigerant
or 110 Defective operation of stop valve
Defective thermistor
Defective outdoor controller board
Defective action of linear expansion
valve
Stop valve of outdoor unit is closed
during operation.
Disconnection or loose connection of
connector (63L) on outdoor controller
board
Disconnection or loose connection of 63L
Defective outdoor controller board
Leakage or shortage of refrigerant
Malfunction of linear expansion valve
Short cycle of indoor unit
Clogged filter of indoor unit
Decreased airflow caused by dirt of
indoor fan
Dirt of indoor heat exchanger
Locked indoor fan motor
Malfunction of indoor fan motor
Defective operation of stop valve
(Not fully open)
Clogged or broken pipe
Locked outdoor fan motor
Malfunction of outdoor fan motor
Short cycle of outdoor unit
Dirt of outdoor heat exchanger
Decreased airflow caused by defective
inspection of outside temperature
thermistor (It detects lower temperature
than actual temperature.)
Disconnection or contact failure of
connector (63H) on outdoor controller
board
Disconnection or contact failure of 63H
connection
Defective outdoor controller board
Defective action of linear expansion
valve
Malfunction of fan driving circuit
Solenoid valve (SV1) performance
failure (High-pressure pressure cannot
be controlled by SV1.)
High-pressure sensor defective
High-pressure sensor input
circuit defective in multi controller board
Disconnection or loose connection of
discharge/compressor temperature
thermistor (TH4)
Defective holder of discharge temperature
thermistor
43
Causes
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Check points
Check intake super heat.
Check leakage of refrigerant.
Charge additional refrigerant.
Check if stop valve is full open.
Turn the power off and check if 5101
is displayed when the power is put
again. When 5101 is displayed, refer to
"Check points" for 5101.
Check linear expansion valve.
Check stop valve.
Check the connector (63L) on outdoor
controller board.
Correct to proper amount of refrigerant.
Check linear expansion valve.
Check indoor unit and repair
defectives.
Check if stop valve is fully open.
Check piping and repair defectives.
Check outdoor unit and repair
defectives.
Check the inspected temperature of
outside temperature thermistor on LED
display.
Check the connector (63H) on outdoor
controller board.
Check linear expansion valve.
Replace outdoor controller board.
Check the solenoid valve performance.
Check the high-pressure sensor.
Check the high-pressure sensor.
Check the installation conditions of
discharge/compressor temperature
thermistor (TH4).