Danfoss DHP-H Installation And Service Instructions Manual Download Page 41

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VMBMA602

1 Heat pump unit

•  Scroll compressor
•  Stainless steel heat exchangers
•  Circulation pumps for brine and heating systems
•  Valves and safety equipment for cooling systems and corresponding electrical components.

2 Water heater

•  180 litres
•  Internal anti-corrosion protection with copper or stainless steel
•  It has an anode that does not require replacing, which means that it is maintenance-free

3 Exchange valve

• The heated water either passes through to the heating system or to the water heater depending on

whether heating or hot water is to be produced

4 Auxiliary heat

• 9 kW electric heating element (4.5 kW at 230 V 1N heat pump installation)
• Electric heating element control in maximum of three steps (five steps for 400 V 3N DHP-A, -AL mod

els)

•  Installed on the heating system’s supply line
•  Covers the demand of extra energy if the heat pump’s capacity is exceeded
•  Automatically connected if operating mode AUTO is selected.

5 Control equipment

•  Control computer with graphic display
•  Temperature sensors (outdoor, supply line, return line, brine and hot water)
•  Room sensor (option)

The control equipment controls the heat pup unit’s included components (compressor, circulation pumps,

auxiliary heaters and exchange valve) and determines when to start and stop the pump as well as produc-

ing heat for the house or hot water.

12.3 Outdoor unit and defroster function, DHP-A, -AL models

The DHP-A and DHP-AL heat pumps are equipped with an outdoor unit that makes use of the energy in the air outdoors down to -20°C.

The outdoor unit has a coil where brine recovers free energy from the outside air. It also has a fan that increases the airflow through the

coil. During operation the coil is cooled by the energy exchange at the same time as the humidity causes it to become covered in frost.

DHP-A, AL models have an automatic function to defrost the coil using the produced heat energy. If necessary, a defrosting sequence starts

which means the following:

• The defrosting sequence starts when the temperature of the brine reaches its set parameter for defrosting.
• The compressor is stopped so that the defrosting sequence should not load the compressor unnecessarily. On the other hand the com

pressor is not stopped when it produces hot water because the water heater is cooled when defrosting. The fan on the outdoor unit is

stopped in conjunction with defrosting to shorten the time of defrosting.

• The shunt valve in the heat pump opens so that hot brine from the defrosting tank is mixed with the cold brine circulating to the out

door unit. The mixture has a temperature of about 15°C.

•  The fifteen degree heated brine melts the frost on the outside of the coil at the same time as the liquid is cooled.
•  When the brine is no longer cooled to temperatures below 11°C the coil is sufficiently defrosted.
•  The shunt valve closes the flow of hot brine from the defrosting tank.
•  Operation returns to normal.

A DHP-A, -AL installation consists of three basic

units:

1 Heat pump unit

•  Scroll compressor
•  Stainless steel heat exchanger
•  Circulation pumps for brine and heating sys

tems

• Valves and safety equipment for cooling sys

tems
and corresponding electrical components.

2 Water heater

• 180 litres
• Internal anti-corrosion protection with cop

per or stainless steel

• It has an anode that does not require replac

ing, which means that it is maintenance-free