Operational Problems - Danfoss DHP-A Service Instructions Manual

Name
Danfoss TUBE R407C, 11.0 kW
Danfoss TUBE R407C, 17,0 kW
Table 12. Break pressure switches
Refrigerant
R134a (Only applies to
certain models of
DHP-C)
R404A (Only applies to
DHP-A, DHP-AL)
R407C
10.4

Operational problems

The tables in the following section apply to all types of heat pump and collector solutions.
The tables list the most probable and common causes of the problem first. When troubleshooting the cause of a
problem start with the first cause and go down the list. There may be more than one way of troubleshooting a
cause where the most probable is given first.
10.4.1 Alarm
Table 13. Problem – Alarm LP (low pressure switch)
Cause
1. Blocked strainer on the brine circuit. Check that the strainer is not blocked.
2. Air in the brine circuit.
3. Closed taps, main tap or filler cock
on the brine circuit.
4. The circulation pump for the brine
circuit is defective or has jammed.
5. Cable break or loose cable to low
pressure switch.
Pressure switch
Low pressure switch
Operating pressure switch
High pressure switch
Low pressure switch
Operating pressure switch A
Operating pressure switch B
High pressure switch
Low pressure switch
Operating pressure switch
High pressure switch
Troubleshooting
Listen for air in the heat pump and brine
circuit.
Check that the shut-off cock or any other
taps are open.
Check:
•
That the circulation pump spins.
•
That the shut-off valves are open.
•
That the strainer is not blocked.
•
That there is no air in the heating sys-
tem.
•
Check that both cables are connected
to the pressure switch.
•
Using the buzzer, check that there are
no cable breaks. In order to do this,
disconnect the cables from the pres-
sure switch and circuit board.
Setting
From fully closed position, screw 6.25 turns out
From fully closed position, screw 5,5 turns out
Break pressure
0.03 MPa
1.80 MPa
2.45 MPa
0.08 MPa
2.65 MPa
2.85 MPa
3,10 MPa
0.08 MPa
2.85 MPa
3,10 MPa
Remedy
Clean the strainer if necessary.
Bleed the brine circuit according to the
installation instructions.
Open closed taps.
The circulation pump may have jammed.
If so, open the bleed screw and try to
release the paddle wheel using a screw-
driver 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
If a cable has come loose, reconnect it.
If there is a cable break, replace the
cable.
Service instructions VMGFC302 – 37