Technical data

Electrical connections Thermo 90 S / Thermo 90 ST
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9.5. Thermo 90 S control module
The control module offers protection type IP6K4K if it is installed in the
position shown in Figure 13.
9.6. Thermo 90 ST control module
The control module offers protection type 6K9K if it is installed in the
position shown in Figure 14.
9.7. To set the regulating temperatures
Thermo 90 S / Thermo 90 ST
If the “Engine on”/”Engine off” signal (terminal D+) is applied to control
module plug X12 contact 7 (Thermo 90 S) or plug X8 contact 7
(Thermo 90 ST), different regulating thresholds take effect
If the terminal D+ signal is not applied, the temperatures are the same
as those at “Engine off”.
NOTE:
The selected regulating pause temperature of the heater should be
lower than the opening temperature of the radiator thermostat.
Fig. 13: Thermo 90 S (from 03/97) control module, installation position
Fig. 14: Thermo 90 ST control module, arbitrary installation position
24 V
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Nominal
temperature at
the sensor
Regu-
lating
pause
Switch on again
after regulating
pause
“Engine on” 72 °C 82 °C 67 °C
“Engine off” 80 °C 90 °C 75 °C