Mitsubishi Electric EHWT17D-MHEDW, Руководство по установке

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Service and Maintenance
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Code Error Cause Action
U2
(1102)
High discharge temperature
(1) Abnormal if TH4 exceeds
125°C or 110°C continuously
for 5 minutes.
(2) Abnormal if discharge super-
heat (Heating: TH4−T63HS)
exceeds 70°C continuously for
10 minutes.
TH4: Thermistor <Discharge>
High comp. surface temperature
Abnormal if TH33 exceeds 125°C.
In the case of high comp. surface
temperature error, compressor
does not restart unless the ther-
mistor (TH33) becomes less than
95°C.
TH33: Thermistor <Comp. sur-
face>
1
Overheated compressor operation
caused by shortage of refrigerant
1
Check intake superheat.
Check leakage of refrigerant.
Charge additional refrigerant.
2
Defective thermistor
23
Turn the power off and check if U3 is
displayed when the power is turned on
again.
When U3 is displayed, refer to 'Judg-
ment and action' for U3.
3
Defective C.B.
4
Defective action of linear expansion
valve
4
Check linear expansion valve.
5
Clogging with foreign objects in refrig-
erant circuit
Note:
Clogging occur in the parts which become
below freezing point when water enters in
refrigerant circuit.
5
After recovering refrigerant, remove wa-
ter from entire refrigerant circuit under
vacuum more than 1 hour.
6
In the case of the unit does not restart:
Detection temp. of thermistor (TH33)
]
95°C
U3
(5104)
Open/short circuit of heat pump
unit temperature thermistor
(TH4, TH33)
Abnormal if open (3°C or less) or
short (217°C or more) is detected
during compressor operation.
(Detection is inoperative for 10
minutes of compressor starting
process and for 10 minutes after
and during defrosting.)
TH4: Thermistor <Discharge>
TH33: Thermistor <Comp. sur-
face>
1
Disconnection or contact failure of
connectors (TH4, TH33) on the C.B.
1
Check connection of connector (TH4,
TH33) on the C.B.
Check breaking of the lead wire for TH4,
TH33.
2
Defective thermistor
2
Check resistance value of TH4, TH33 or
temperature by microprocessor.
3
Defective C.B.
3
Replace C.B.
U4
(TH3:
5105)
(TH7:
5106)
(TH8:
5110)
(TH32:
5132)
(TH34:
5134)
Open/short of heat pump unit
thermistors
(TH3, TH32, TH34, TH7 and TH8)
Abnormal if open or short is detected
during compressor operation.
Open detection of TH3, TH32 and
TH34 is inoperative for 10 seconds
to 10 minutes after compressor
starting.
Note:
Check which unit has abnormality
in its thermistor by switching the
mode of SW2. (PAC-SK52ST)
1
Disconnection or contact failure of
connectors
C.B.: TH3, TH32, TH34, TH7
Power board: CN6
1
Check connection of connector (TH3,
TH32, TH34 TH7) on the C.B.
Check connection of connector (CN6)
on the power board. Check breaking of
the lead wire for TH3, TH32, TH34, TH7,
TH8.
2
Defective thermistor
2
Check resistance value of TH3, TH32,
TH34,TH7,TH8 or check temperature by
microprocessor.
3
Defective C.B.
3
Replace C.B.
Note:
Emergency operation is available in
case of abnormalities of TH3 and TH7.
U5
(4230)
Temperature of heat sink
Abnormal if TH8 detects tempera-
ture indicated 95°C.
TH8: Thermistor <Heat sink>
1
Rise of ambient temperature
1
Check if there is something which caus-
es temperature rise around unit.
(Upper limit of ambient temperature is
35°C.)
Turn off power, and on again to check if
U5 is displayed within 30 minutes.
If U4 is displayed instead of U5, follow
the action to be taken for U4.
2
Defective thermistor
2
Check resistance value of TH8 or tem-
perature by microprocessor.
3
Defective input circuit of power circuit
board
3
Replace power circuit board.
U6
(4250)
Power module
Check abnormality by driving
power module in case overcurrent
is detected.
(UF or UP error condition)
1
Decrease of power supply voltage
1
Check facility of power supply.
2
Looseness, disconnection or converse
of compressor wiring connection
2
Correct the wiring (U•V•W phase) to
compressor.
3
Defective compressor
3
Check compressor
4
Defective power circuit board
4
Replace power circuit board
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