Fault
code
Fault
Cause/Remedy
07
No feedback external fan/com-
pressor
Check the connections of the ex-
ternal fan (voltage and velocity
sensor); check the fan motor;
check the compressor connec-
tion and motor
08
Processor fault external fan
Overheating/overvoltage at the
external fan controller; air inlet
blocked; motor jumper incor-
rectly placed on the controller;
check external fan motor
09
External fan idle
Check external fan
10
Max. speed of the external fan
exceeded
Wind-influenced excess air inlet
on the suction side; if required, fit
wind break; electromagnetic
faults
11
Compressor processor fault
Overheating/overvoltage at the
compressor speed controller; air
inlet blocked; check compressor
motor
12
Compressor idle
Checking the compressor
13
Max. compressor speed ex-
ceeded
Restart; if problem persists, re-
place controller
14
Excessive compressor power
consumption
Checking the compressor
15
DC undervoltage
DC voltage below limit; replace
controller
16
DC overvoltage
Check mains voltage (max.
264 V~); if OK then replace con-
troller
17
AC undervoltage
Check mains voltage (min.
198 V~); if OK then replace con-
troller
18
No connection to the internal
device A
Check the connecting cable be-
tween the internal device, the ex-
ternal unit and earth
19
No connection to the internal
device B
20
No connection to the internal
device C
*
1
21
No connection to the internal
device D
Diagnosis
(cont.)
23
Troubleshooting
5692
689
GB
*1
Not applicable to type OT307H.