Cause
Troubleshooting
Remedy
5. Defective or incorrectly set motor
protection.
Use a hook-on meter to establish when
the motor protection deploys, check what
the motor protection is set to.
Compare with the table. For three phase
heat pumps all three phases must be sup-
plied.
If the motor protection is defective,
replace it.
If incorrectly set, adjust to the correct
value.
6. Defective compressor.
Measurement check the voltage on the
phase(s) (each to zero) at the compressor.
There must not be any large deviation
between the phases. If measurement
checking the winding’s resistance the
same value must be on one to three wind-
ings.
If the compressor is defective, replace it.
7. Alarm from single phase soft starter. Check the fault cause using the soft start
LEDs.
Table 9.
Problem – Alarm sensor (all)
Cause
Troubleshooting
Remedy
Sensor fault alternatively cable fault.
•
When reading the resistance of the
sensors, the sensor leads must first
be disconnected from the control
equipment or terminal block.
•
First take a reading from the sensor
including cable and check against
the ohm table in Symbols on decals.
•
If the read off value does not corre-
spond with the table, only measure
the sensor and check the ohm table
in Measurement points, Page 11.
If the sensor gives a correct value, the
cable is defective.
If the sensor does not give a correct
value, the sensor is defective.
Table 10.
Problem – Err phase seq.
Cause
Troubleshooting
Remedy
The incoming phases have the incor-
rect sequence (only applies to 3-phase
heat pumps), appears after a minute
when the compressor is started.
•
If the text HEAT / PRESSURE ERROR is
displayed it can mean that the pha-
ses are in the incorrect order.
•
When the compressor is running,
check the pressure pipe temperature
by feeling the pressure pipe. If the
phases are correctly sequenced it
should be hot (not just warm) even a
distance from the compressor.
•
When the compressor runs with the
phases incorrectly sequenced a
strange noise may be heard (loud,
rattling) when the compressor runs
backwards.
If the phases are in the incorrect order,
switch two incoming phases at the main
terminal block and recheck according to
the troubleshooting window.
18 – Service instructions VMGFJ102
