2|  Key features
2.1|  Voltage protection
Protection against high and low voltage by limiting the 
compressor operation within specified voltage limits. 
Whenever the supply voltage goes beyond the defined 
voltage protection limits controller will shut the compressor 
OFF and flashes alarm on the display. 
It will restore the operation when the voltage falls under the 
operating range respecting minimum stop time.
2.2|  Compressor protection
Parameters for Minimum ON and OFF time, protect the 
compressor by short cycling/sudden switching ON and OFF 
by defining minimum ON and OFF time.
2.3|  Compressor protection against 
  high condensing temperature
If the condenser is blocking up with dirt and thereby reaches 
a too high condensing temperature, controller will give 
the user early warning through condenser alarm and if 
temperature rises further it will switch the compressor OFF. 
If the temperature measured by the condenser sensor (Sc) 
is reaching the set ”pre alarm limit” a alarm is raised, but no 
further action is taken. 
This is used to indicate to the user that something is wrong 
with the condenser. Often the reason is that that the air flow 
to the condenser is restricted (dirt) or because the condenser 
fan is broken. 
The alarm will reset if the condenser temperature drops back 
by 5 °C. If the measured condenser temperature continues 
to increase and reaches the set “Block limit” the compressor is 
stopped and it is restricted from starting again until the alarm 
is reset manually.
High voltage limit
High voltage cut-in
limit (compressor start)
Low voltage cut-out
limit (alarm and
compressor stop)
Power to compressor
min run time
ON
OFF
CUT-IN
CUT-OFF
min stop time
time
time
T