Danfoss DHP-AL Installation And Service Instructions Manual page 46

Problem – Incorrect phase sequence
Cause
The incoming phases have the incorrect
sequence (only applies to 3-phase heat
pumps).
Problem – Alarm TS (addition)
Cause
1. The overheating protection has tripped.
2. Phase drop.
The alarm occurs when 230 V is not regis-
tered between incoming L2 on the circuit
board and zero on block 220.
3. Overheating protection fault, cannot be
reset.
4. Flow sensor fault.
5. No or insufficient circulation in the heat-
ing system.
6. The submersible tube in the electric heat-
ing element is against the coils.
Problem – Alarm Brine out
Cause
1. Defective sensor.
2. Brine temperature too low.
46
Troubleshooting
• If the text ERR PHASE SEQ appears in the
display when the heat pump is powered,
(only appears in the first 10 minutes) this
means that the phases have the incorrect
sequence.
• When the compressor is running, check
the delivery pipe temperature by feeling
the delivery pipe that should be hot (not
just warm) even a little distance from the
compressor if the phases are correctly
sequenced.
• When the compressor runs with the phas-
es incorrectly sequenced a strange noise
may be heard (loud, rattling) when the
compressor runs backwards.
Troubleshooting
Check if the overheating protection has
tripped.
• Check if the overheating protection has
tripped.
• Check if any cables at the circuit board or
overheating protection are loose or dam-
aged.
Press the reset button, measurement check
for 230 V on the incoming and outgoing
connections.
Check what the flow sensor shows, is it a
plausible/actual value?
Measure the resistance of the sensor, check
against the ohm table in the "Measurement
points" section.
Check:
• That the circulation pump spins.
• That the shut-off valves are open.
• That the strainer is not blocked.
• That no air is in the heating system.
Check what the flow temperature is when
the overheating protection trips. It normally
trips at about 95°C.
Troubleshooting
Check what the sensor shows, is it a plausi-
ble/actual value?
Measure the resistance of the sensor, check
against the ohm table in the "Measurement
points" section.
Check the set value on ALARM BRINE in the
heat pump's control computer.
VMBME102
Remedy
If the phases are in the incorrect order,
switch two incoming phases at the main
terminal block and recheck according to the
troubleshooting window.
Remedy
If the overheating protection has tripped,
reset it.
If the overheating protection has tripped,
reset it.
If the cables are loose/damaged, secure or
replace them.
If the overheating protection is defective,
replace it.
If the sensor is defective, replace it.
The circulation pump may have jammed, if
so, open the bleed screw and try to release
the paddle wheel using a screwdriver for
example.
Open closed valves or taps.
Check, and, if necessary, clean the strainer.
If necessary, bleed the heating system
according to the installation instructions.
The submersible tube can be prised out
slightly from the coils using a screwdriver
or similar. The submersible tube must be
vertical.
Remedy
If the sensor is defective, replace it.
The alarm is triggered when the tempera-
ture on BRINE OUT is as low or lower than
the set value on ALARM BRINE. In the fac-
tory setting this function is inactive.