KGL Operating Manual – UA 412 S
2019-01-14
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If the forcibly actuated shutdown is active, the shutdown will already be ended before expiry of the
specified duration if the supply air sensor has experienced heating of 4 K.
5.5.5 Minimum running and standstill times
As high switching frequency of the compressors can occur, e.g. in the case of low selected hysteresis,
monitoring has been installed that guarantees minimum running and standstill times.
This means: if a compressor has been switched off during normal operation due to the occurrence of a
shutdown condition, it remains switched on until expiry of the minimum running time. If the minimum running
time has elapsed and the setpoint is not reached until then, the compressor is switched off immediately. The
same behaviour applies for the switching on of the compressor during the minimum standstill time.
5.5.6 Emergency operation
In the event of a failure of the temperature measurement, i.e. the control temperature sensor, the cooling can
continue running with an adjustable run time (0...100%) (menu 6-3). The interval for the emergency operation
is 10 minutes, i.e. for 10% run time, the compressor enable switches ON for 1 minute and OFF for 9 minutes in
each case.
5.6 Defrost
Fire hazard! For fire prevention reasons, a device for shutting down the defrost heating in the event
of excessive temperature (e.g. “KLIXON”) must be planned during the planning of the installation.
5.6.1 General notes for defrost
The defrost counteracts the icing-up of the evaporator by the normal controlled operation. Thereby, the
temperature regulation of the refrigeration point is switched off.
Controller type SPIR410
The controller has a relay for control of a defrost heater for active defrost of the evaporator. Off-cycle defrost
takes place if the defrost heater is not connected.
Controller type SPIR290
The evaporator is defrosted using off-cycle defrost.
