Danfoss DHP-A Service Instructions Manual page 11

If the thermal over current relay (position 1 in the image below) is activated, the heat pump's normal operation is
blocked, an alarm indicator on the heat pump's control panel flashes and a warning text appears in the display of
the control panel.
The blocked heat pump is reset by setting the operating mode to OFF and then back to the previously selected
mode.
The compressor is also equipped with an internal protector that stops the compressor if it risks becoming overhea-
ted. The internal protector cannot be reset manually, the compressor must cool before it can be restarted. No
alarm connected to this protector.
Circulation pumps
The circulation pumps have internal overload protectors, which are reset automatically after cooling.
The overload protectors in circulation pumps for 10 - 16 kW heat pumps (8 - 12 kW air/water heat pumps) also
activate the alarm for motor protection and block the heat pump's normal operation. Indication and resetting
occur in the same way as for the compressor.
Alarm mode
If an alarm that affects the heat pump's normal operation is activated this will be indicated in the display window.
In order to further attract attention, the heat pump will not produce hot water.
The heat pump will initially meet the heat demand using the compressor. If this is not possible, the built-in electric
heating element engages.
Auxiliary heater, electric heating element
The auxiliary heater consists of an electric heating element mounted on the heating system supply line. It has an
overheat protector that switches off the electric heating element if it is at risk of becoming overheated. The over-
heat protector's control unit is on the electrical panel (position 2 in the image below).
If the overheat protector is activated an alarm indicator flashes on the heat pump's control panel and a warning
text appears.
The overheat protector is reset by pushing the reset button (position 3 in the image below).
Electrical system
The heat pump control is fused with fuse F0 (position 4 in the image below).
2
3
Figure 2. Component location
Technical data
See Technical data for detailed technical specifications.
Symbol explanation
1
2
1
3
4
4
Thermal over current relay F11
Overheating protection
Reset button
Fuse F0
Service instructions VMGFC302 – 9