Danfoss AK-CC55 Water Loop - Voltage Signal

A B
1
Danfoss 84B8302
A
B
c86 ON time emergency
c87 OFF time emergency
Emergency control
If the thermostat air temperature becomes invalid due to a sensor error on the thermostat sensor, the controller will
go into an emergency control mode where cooling will be maintained.
For single or dual compressor applications the compressor cut-in and cut-out periods can be dened as shown in
the Figure 17.
Figure 17: Compressor cut-in/cut-o period
For dual compressors it will only be one compressor, which will follow the dened cut-in and cut-out periods.
Variable speed-controlled compressor/pump will run with a dened emergency speed during the emergency
cooling. As soon as the thermostat sensor is okay again, normal control will be resumed.
Variable speed signal
The speed control signal is provided via the analogue output AO1 and it can be set up for:
• Voltage
• Frequency
• PWM
For the selected control signal, the user must dene the minimum output signal and the maximum output signal
which will then correspond to respectively 0% and 100% capacity.
Based on the compressor data, a minimum speed and a start speed must be dened as a percentage of full capacity.
Voltage signal
Figure 18: Capacity curve
Compressor
relay
Start
4.5 V
o28 AO1 Max voltage
10 V
o27 AO1 Min voltage
0 V
c46 Min speed
20%
c47 Start speed
45%
c48 Max speed
100%
Requested
capacity
AO1 voltage
Min
2.0 V
Danfoss 84B8303
A capacity curve could look like shown in Figure 18. The analogue output signal is set to 0 – 10 V and the minimum
speed is set at 20% and start speed at 45%.
Example:
o09 AO1 signal type = voltage
o28 AO1 max. voltage = 10 V
o27 AO1 min. voltage = 0 V
c46 min. speed = 20%
c47 start speed = 45%
c48 max. speed = 100%
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AK-CC55 Water Loop