Applications
The controller supports the following 3 control modes:
- Sequential On/Off control of 2 compressors.
Output 1 will form the base load, and output 2 will connect a
lower capacity so that the variation of the cabinet temperature
is kept to a minimum.
The compressors are coupled sequentially. Compressor 1 is first
in and last out.
- Cyclic On/Off control of 2 compressors.
Here the compressors must be of equal size, and they are
coupled cyclic.
The runtimes are equalized.
- Variable speed control of one compressor
Here one compressor output is used together with the analogue
0 – 10 V signal.
Enables a very precise control of the cabinet temperature.
Control with two compressors
When the controller calls for refrigeration, compressor 1 will be
cutin to the circuit first.
After the delay time, compressor 2 will be coupled to the circuit.
When the temperature has reached the middle of the differential,
compressor 2 will be cut out.
Compressor 1 will continue until the temperature has reached the
cut-out value. Then it will cut out. When the temperature again
reaches the middle of the differential, compressor 1 will be cutin to
the circuit again.
If compressor 1 cannot maintain the temperature within the dif-
ferential, compressor 2 will also be cutin to the circuit.
The compressor's settings for ”Min On time” and ”Min Off time”
will always have top priority during normal regulation. But if one
of the override functions is activated, the ”Min On time” will be
disregarded.
With cyclic control the compressor with the lowest runtime will be
started first.
If one of the compressors has been running continuously for
two hours, the compressors will be alternated to assure runtime
equalization.
Variable speed control
Here the compressor will be started when the controller requests
cooling.
The analogue output will then be used to control the speed so
that the temperature is kept very accurate at the reference.
The actual reference is the set cut-out temperature plus half the
set difference.
User Guide | Controller for SemiPlugin appliance, AK-CC 460
© Danfoss | DCS (vt) | 2019.12
BC230086440483en-000201 | 3