Danfoss ADAP-KOOL AK-HP 780 Design Manual page 44

Heat pump controller with oil management, refrigeration control systems

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Heat pump plant example

We have decided to describe the setup by means of an example

comprising a compressor group and a "pump".

The example is the same as the one given in the "Design" section,

i.e. the controller is an AK-HP 780 + extension modules.

Compressor Group

• Refrigerant CO2 (R744)

• 4 only compressors with "Best fit". Speed control on one.

• Safety monitoring of each compressor

• Common high-pressure monitoring

• Sctrl setting 60°C, Night setback on 5 K

• Oil management of each compressor

• Pulse reset of stopped compressor (oil shortage)

Pump:

• Pump with speed control

• S7 setting 40°C

Receiver:

• Monitoring of liquid level of refrigerant

• Control of pressure in oil receiver

Fan in plant room:

• Thermostat control of fan in engine room

Safety functions:

• Monitoring of P0, Pc, Sd and superheat in suction line

• P0 max = 10°C, P0 min = -2°C

• Pd max = 50 °C

• Sd max = 120°C

• SH min = 5 °C, SH max = 35 °C

• Monitoring of low and high level in oil receiver

Other:

• Alarm output used

• External main switch used

For the example shown we use the following modules:

• AK-HP 780 controller

• AK-XM 102B digital input module

• AK-XM 205B input and output module

• AK-OB 110 analog extension module

There is also an internal main switch as a setting. Both must be "ON"

before any adjustment is made.

The modules used are selected in the design phase.

AK-HP 780

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