Danfoss DHP-AT, Руководство по установке

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The heat pump then starts defrosting in intervals of 40 minutes of compressor running time. The defrosting sequence stops after the
defrosting time setting has been reached.
Defrosting abnormal termination
If the heat pump is switched off (on the operator panel) during the defrosting cycle, the defrosting will continue until the defrosting stop
condition has been met and then the heat pump stops.
In case of a high pressure protection situation during defrosting, defrosting stops and the heat pump shuts down as a protection.
If there is a power failure during defrosting, when the power returns, the compressor will start testing the coil temperature after 10
minutes of operation. If the defrost conditions are met, the heat pump will start to defrost.
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Low pressure protection is ignored during defrosting. After the defrosting has stopped and the normal heat-
ing operation has started again, it takes 1 minute before the low pressure switch is tested.
Legionella prevention
DHW tank with built-in electrical heater
There is an automatic legionella prevention when the heat pump function is set to DHW. The automatic legionella prevention runs at
00:00 every 7:th day of operation. The maximum water temperature for DHW is 55°C running on compressor only. The water in the hot
water tank will be heated to 65 °C for 15 minutes, using the hot water tank electrical heater. This will kill any possible legionella bacteria
inside the hot water tank.
DHW tank without built-in electrical heater
There is an automatic legionella prevention when the heat pump function is set to DHW. The automatic legionella prevention runs at
00:00 every 7:th day of operation. The water in the hot water tank will be heated to 55 °C for 3 hours then returns back to previous
operating mode.
Freeze protection
There is an automatic freeze protection function in the unit that works in two steps.
Step 1: When there is a risk of freezing due to low temperatures, the unit will start the water pump to create a water flow in the system.
Step 2: To automatically start the heating operation.
Freeze protection, step 1
When the operational status of the heat pump is Standby or powered ON, and the outside ambient air temperature is below 2°C, and the
return water temperature is below 8°C, the unit will automatically start operating in water pump mode.
The heat pump will exit the freeze protection mode when the ambient air temperature is above 3°C or the return water temperature is
above 10°C. When this protective function is triggered, the operator panel will display "Err 19", but this is not a fault.
The unit will automatically recover once the conditions in the control system is met.
Freeze protection, step 2
When the return water temperature is below 6°C, the unit will automatically start the heating operation. It will exit step 2 protection
when the ambient temperature is above 3°C or the return water temperature is above 15°C. When this protective function is triggered,
the operator panel will display "Err 18", but this is not a fault.
The unit will automatically recover once the conditions in the control system is met. When the operational status of the heat pump is
"ON", the machine will start the domestic hot water function compulsorily if the water tank temperature is below 13°C; then exit and
return to previous status when the water temperature is above 16°C. The operator panel will display "Err 18", but this is not a fault.
The unit will automatically recover once the conditions in the control system is met.
4.3.2 Operating heat pump in MANUAL mode
In MANUAL mode, the heat pump provides a constant water temperature according to the temperature settings in the control system.
The user can change the temperature settings for the supply line, which in turn affects the temperature in the house. Heat curves cannot
be selected in manual mode. The user can start and stop house heating/cooling or production of DHW from the operator panel.
Installation Guide DHP-AT
Danfoss Heating Solutions VMGFI302
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