Specifications
RK0YG302 © Danfoss 04/2007 9
C = compressor, L = Unloader
EKC 331T
Relay module
The controller can also be used as a relay module where the relays
in the module are operated by the received voltage signal. The
signal must be connected to terminal 15-16.
Depending on the denition of the signal and the number of
relays used, the relays will be ”distributed” over the signal.
A hysteresis at the individual coupling points will ensure that the
relay will not cut in or out when not required.
Sequential
The relays are here cut in in sequence – rst relay number 1, then
2, etc.
Cutout takes place in the opposite sequence, i.e. the last cut-in
relay will be cut out rst.
Cyclic
The relays are coupled here so that the operating time of the
individual relays will become equalised.
At each cutin the regulation scans the individual relays’ hours,
cutting in the relay with least time on it.
At each cutout a similar thing happens. Here the relay is cut out
that has most hours on the hours.
If capacity regulation is carried out on two compressors with one
unloader each, the following function can be used:
Relays 1 and 3 are connected to the compressor motor.
Relays 2 and 4 are connected to the unloaders.
Relays 1 and 3 will operate in such a way that the operating time
for the two relays will become equalised.
Rx = random relay
h = number of hours