Spheros thermo 231, Workshop Manual

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Thermo 230 / 231 / 300 / 301 / 350 5 Troubleshooting
501
5 Troubleshooting
5.1 General
This section describes troubleshooting procedures for the
heaters
Thermo 230, 231, 300, 301 and 350 .
CAUTION
Troubleshooting requires profound knowledge about
components and their theory of operation and may only be
performed by trained personnel.
In case of doubt functional interrelations may be derived
from Sections 2 and 3.
CAUTION
Troubleshooting is normally limited to the isolation of
defective components.
The following possible causes for trouble have not been
taken into consideration and must always be excluded
as a possible cause for malfunction:
corrosion on connector
loose contact on connector
wrong crimping on connector
corrosion on wiring and fuses
corrosion on battery terminals
After any fault correction a functional checkout in the
vehicle has to be performed.
5.2 General Fault Symptoms
The following table (Fig. 501) lists possible fault
symptoms of general nature.
Symptom Probable Cause
Fault in electrical system
Operating indicator light is not on, no heater operation. • no power supply
• fuses
• wiring to terminals of connector A of control unit.
Fuse F2 blows. Short circuit in circulation pump or in wiring to heater.
Fuse F3 blows. Short circuit in wiring to heater/motor/nozzle block
preheater (if installed).
Normal heater operation, operating indicator light is out. Operating indicator light defective or wiring to light open
or shorted.
Fault in water system
Circulation pump not operating
(U 4851 and Aquavent 6000 S only) • Failure mode activated
The failure mode switches the motor off in case of mal-
functions. After approx. 5 sec the failure mode switches
the motor to the power saving sleep mode.
In the sleep mode the internal consumers of the motor
electronics are switched off. The power consumption in
this mode then amounts to < 2 mA.
The motor can be reactivated out of the sleep mode by
disconnection of the power supply for approx. 2 minutes.
After power reconnection the motor will again run up with
a soft start.
Fig. 501 General Fault Symptoms (Sheet 1 of 3)