15
8 Maintenance
The controller and mains transformer do not require any maintenance.
The controller does not have any fuses so, if brief voltage spikes occur,
the refrigeration system will not stop operating for a prolonged period.
Once the disturbance has passed, the controller will automatically start
up again.
Cleaning the housing: Only a dry anti-static cloth may be used to wipe
clean all plastic parts. Do not use water or cleaning agents containing
solvents!
9 Alarm messages
If an alarm occurs, a code on the display will alternate with the cold
store temperature and the alarm relay (PCR-410 only) will switch on.
Display
Meaning
AL1
Program memory data loss. The preset values
will be used as an emergency program.
The setpoint value will be set to +4 or
–18 °C, depending on the selection of DIP
switch 1.
AL2
Limit value (= setpoint value + E03) at sensor T1
exceeded and delay time E04 elapsed.
AL3
The sensor temperature at sensor T1 is above
50 °C or below –55 °C.
AL4
The specified setpoint value is outside the limits
E12 and E13
AL5
Cold store temperature sensor T1 – short circuit
or break in wiring. Compressor switches as a
function of parameter E17
AL6
Evaporator temperature sensor T2 – short circuit
or break in wiring.
Safety times are used, for the fan run-on function
the fan is controlled with the compressor by the
evaporator fan control E11 automatically switching
from 3 to 1.
☛
After sensor T2 has been repaired,
E11 must be reset manually from 1 to 3.