EN
Troubleshooting
MDC065(K), MDC090(K)
36
11
Troubleshooting
The significance of the red LED (fig.
1
2, page 3)
For operational faults it illuminates several times. The number of pulses de-
pends on the type of fault.
Each flash lasts for one quarter of a second. After the series of impulses a
pause follows. The sequence for the fault is repeated every four seconds.
Interior temperature too low in control level “1”
Compressor does not run (battery connection)
Number of
flashes
Fault
Possible cause
1
Supply voltage
The supply voltage is outside of the set
range.
2
Excessive fan current
The fan loads the electronics unit with
more than 1 A.
3
The motor doesn't start
The rotor is jammed.
The pressure difference in the cooling
system is too high (> 5 bar).
4
Speed too low
If the cooling system is overloaded, the
minimum speed of the motor of 1850
RPM cannot be maintained.
5
Overheating of the electron-
ics unit
If the cooling system is loaded too heav-
ily or the temperature is set too high, the
electronics can overheat.
Fault
Possible cause
Remedy
Compressor runs con-
stantly
Faulty thermostat
Change the thermostat
Compressor runs for a
long time
Large quantities have been frozen in
the freezer compartment
–
Fault
Possible cause
Remedy
U
KL
= 0 V
There is an interruption in the connec-
tion between the battery and the –
electronics
Establish a connection
Main switch faulty (if installed)
Replace the main switch
Additional supply line fuse has blown
(if installed)
Replace the supply line
fuse
U
KL
≤
U
EIN
Battery voltage is too low
Charge the battery
