Voltage Signal - Danfoss AK-CC55 Water Loop User Manual

AK-CC55 Water Loop
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 defined as shown in
the Figure 17.
Figure 17: Compressor cut-in/cut-off period
1
A
For dual compressors it will only be one compressor, which will follow the defined cut-in and cut-out periods.
Variable speed-controlled compressor/pump will run with a defined 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 define 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 defined as a percentage of full capacity.

Voltage signal

Figure 18: Capacity curve
AO1 voltage
o28 AO1 Max voltage
10 V
Start
4.5 V
Min
2.0 V
o27 AO1 Min voltage
0 V
c46 Min speed
20%
Compressor
relay
A capacity curve could look like shown in
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%
© Danfoss | Climate Solutions | 2022.04
B
c47 Start speed
45%
Figure 18. The analogue output signal is set to 0 – 10 V and the minimum
A c86 ON time emergency
B c87 OFF time emergency
Requested
capacity
c48 Max speed
100%
BC378540472015en-000101 | 13