151
F.984 Multiple electrical fault, control of electronic expansion valve 1
F.984
System characteristics
The refrigerant circuit will not start.
Cause
Control fault, electronic expansion valve 1:
■
Stator of expansion valve 1 faulty
■
Expansion valve 1 blocked in "open" position
■
Expansion valve 1 clogged
Measures
1. Check connections X8.1 to X8.5 on the VCMU
refrigerant circuit controller:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
Replace cable if necessary.
2. Isolate the system from the power supply. Wait at
least 2 min. Switch on the system.
3. Check electronic expansion valve 1 via actuator
test.
4. Check resistor R for 20 °C on disconnected plug of
electronic expansion valve 1:
On all 4 coils of the stator between pin 5 and pin 1
to 4 in each case: If R < 43
Ω
or > 49
Ω
, replace sta-
tor.
5. Replace VCMU refrigerant circuit controller.
6. Check electronic expansion valve 1 mechanically:
■
Expansion valve 1 is open and blocked: Suction
gas pressure too high
■
Expansion valve 1 clogged: Suction gas pressure
too low
■
Expansion valve 1 sticks: Suction gas pressure
fluctuates.
7. Replace electronic expansion valve 1.
8. Unlock refrigerant circuit via ViGuide.
F.985 Multiple electrical fault, control of electronic expansion valve 2
F.985
System characteristics
The refrigerant circuit will not start.
Cause
Control fault, electronic expansion valve 2:
■
Stator of expansion valve 2 faulty
■
Expansion valve 2 blocked in "open" position
■
Expansion valve 2 clogged
Measures
1. Check connections X8.1 to X8.5 on the VCMU
refrigerant circuit controller:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
Replace cable if necessary.
2. Isolate the system from the power supply. Wait at
least 2 min. Switch on the system.
3. Check electronic expansion valve 2 via actuator
test.
4. Check resistor R for 20 °C on disconnected plug of
electronic expansion valve 1:
On all 4 coils of the stator between pin 5 and pin 1
to 4 in each case: If R < 43
Ω
or > 49
Ω
, replace sta-
tor.
5. Replace VCMU refrigerant circuit controller.
6. Check electronic expansion valve 2 mechanically:
■
Expansion valve 2 is open and blocked: Low pres-
sure too high
■
Expansion valve 2 clogged: Low pressure too low
■
Expansion valve 2 sticks: Low pressure fluctuates.
7. Replace electronic expansion valve 2.
8. Unlock refrigerant circuit via ViGuide.
Messages
Fault messages (cont.)
6218234
Diagnosis
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