Danfoss DHP-AL Installation And Service Instructions Manual page 47

Problem – Alarm Brine flow low
Cause
1. Incorrect system selected in the control
computer.
If the system does not contain a flow switch
but the control computer is set for the sys-
tem with flow switch, this alarm occurs.
2. Insufficient flow.
Problem – Operating pressure switch open alternatively high hot gas temperature (indicated
left-hand corner)
Cause
1. The operating pressure switch does not
close again.
2. Sensor fault, shows >120°C
3. Hot gas temperature too high.
4. Overheating too high.
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?
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 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 DELIVERY PIPE in the
heat pump's control computer (factory set-
ting 120°C)
Using manometer apparatus and thermom-
eter check what the overheating reading of
the unit is.
Also check that bulb and capillary tube are
undamaged and that the bulb is correctly
installed.
VMBME102
Remedy
If the incorrect system is selected , change
it.
The ground water pump must start and run
together with the heat pump's integrated
brine pump.
Check against the wiring diagram that the
flow switch is correctly connected.
Check that the flow switch is set for the cor-
rect working range according to the flow
switch instructions.
If the exchanger is blocked, clean or replace
it.
in the display's lower
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 in the dis-
play 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 carefully
tapping the head of the pressure switch
with a screwdriver and using the buzzer 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 symbol appears when the delivery pipe
temperature is as high or greater than the
set value for DELIVERY PIPE.
If the overheating reading does not corre-
spond with the instructions for the specific
refrigerant, adjust the expansion valve until
the correct value is obtained. See separate
instructions for cooling techniques.
If overheating cannot be adjusted with the
expansion valve or if the capillary tube/bulb
is damaged, replace it.
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