Mitsubishi Electric PUHZ-W90VHA, Руководство по обслуживанию

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13
<Abnormalities detected while unit is operating>
Error Code
Abnormal point and detection method Judgment and action
U1
High pressure (High-pressure switch
63H activated)
Abnormal if high-pressure switch 63H is
activated (
+
) during compressor opera-
tion.
+ 4.15 MPa
63H: High-pressure switch
Decreased water flow
Clogged filter of water pipe
Dirt of plate heat exchanger
Locked water pump
Malfunction of water pump
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 operation of linear
expansion valve
Malfunction of fan driving
circuit
~ Check water circuit and repair the defect.
Check piping and repair the defect.
~ Check outdoor unit and repair the defect.
Check the detected temperature of outside
temperature thermistor on LED display.
(SW2: Refer to 8-7.)
~ Turn the power off and check F5 is
displayed when the power is turned on again.
When F5 is displayed, refer to “Judgment
and action” for F5.
Check linear expansion valve.
Refer to 8-5.
Replace outdoor controller board.
Case
U2
High discharging temperature
(1) Abnormal if discharge temperature
thermistor (TH4) detects 125
or
110 continuously for 5 minutes.
Abnormal if during defrosting and dis-
charge temperature thermistor (TH4)
detects 110
continuously for 30
minutes.
Overheated compressor
operation caused by insufficient
refrigerant
Defective thermistor
Defective outdoor controller
board
Defective operation of linear
expansion valve
Check intake super heat.
Check leakage of refrigerant.
Charge additional refrigerant.
Turn the power off and check if U3 is dis-
played when the power is turned ON again.
When U3 is displayed, refer to “Judgement
and action” for U3.
Check linear expansion valve.
Refer to 8-5.
U3
Open/short circuit of discharge
temperature thermistor (TH4)
Abnormal if open (3 or less) or short
(217 or more) is detected during
compressor operation.
(Detection is inoperative for 10 seconds to
10 minutes of compressor starting process
and for 10 minutes after or during defrost-
ing.)
Disconnection or contact
failure of connector (TH4) on
the outdoor controller circuit
board.
Defective thermistor
Defective outdoor controller
circuit board
Check connection of connector (TH4) on the
outdoor controller circuit board.
Check the lead wire for thermistor (TH4).
Refer to 8-6.
Check resistance value of thermistor (TH4) or
temperature on LED display.
(Thermistor/TH4: Refer to 8-5.)
(SW2 : Refer to 8-7.)
Replace outdoor controller board.