Danfoss DHP-AX Installation And Service Instructions Manual page 52

Cause
2. Brine temperature too low.
Problem – Alarm Brine flow low
Cause
1. Incorrect system selected in
the control system.
If the system does not contain
a flow sensor but the control
system is set for the system with
flow sensor (e.g. VL+F), this alarm
occurs.
2. Insufficient flow.
Problem – Operating pressure switch open alternatively high hot gas temperature
(indicated by
Cause
1. The operating pressure switch
does not close again.
2. Sensor fault, shows >120°C
3. Hot gas temperature too high.
52 – Service
Troubleshooting
Check the set value on ALARM BRINE in
the heat pump's control computer.
Troubleshooting
In the menu SYSTEM, check which is
selected.
• Check whether the ground water pump
is running?
• Check the flow switch.
• Calibration/setting the flow switch.
• Blocked exchanger?
in the display's lower left-hand corner)
Troubleshooting
1. Switch off the main switch for the heat
pump, wait until the compressor has
been stationary for at least 15 minutes.
2. Disconnect the two cables on the pres-
sure switch, using a buzzer check if the
pressure switch is closed.
Check what the sensor shows, is it a plau-
sible/actual value?
Measure the resistance of the sensor,
check against the ohm table in section
15.3 Measurement points.
Check the set value on PRESS. PIPE in the
heat pump's control computer (factory
setting 130°C)
Remedy
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.
Remedy
If the incorrect system is selected, change
it.
The ground water pump must start and
run together with the heat pump's inte-
grated brine pump.
Check against the wiring diagram that
the flow switch is correctly connected.
Check that the flow switch is set for the
correct working range according to the
flow switch instructions.
If the exchanger is blocked, clean or
replace it.
Remedy
If the pressure switch is closed, bridge
the pressure switch cables temporarily
and switch on the current to the heat
pump again. If there is an indication
the display this means that the pressure
switch is fault-free and the problem is in
the wiring or in the circuit board.
If the pressure switch is open, try care-
fully tapping the head of the pressure
switch with a screwdriver and use a buz-
zer test to see if it has closed again.
Replace the pressure switch if it appears
to jam repeatedly.
If the sensor is defective, replace it.
The square symbol appears when the
pressure pipe temperature is as high or
greater than the set value for PRESS. PIPE.
VMBMH302
in