5
5
4
1
5a
Excess Temperature Protection
18
12. Excess Temperature Protection
If a safety feature is triggered:
•
The fault control lamp 4 lights up.
•
all voltage conducting unit components (the heating
element) are switched off immediately i.e. the safety
circuit transfers the unit to a stable, safe condition.
The fault cause must be identified and remedied.
After the fault has been eliminated the unit can be started
again by pressing the outer ring 5a.
12.1
Excess temperature protection dial
It offers protection against dangers caused by an uncon-
trolled heating up of the heat transfer liquid above the de-
sired set temperature.
The cut-off temperature is adjusted with the excess temper-
ature setting dial 5.
Proper protection can only be guaranteed if the
cut-off point has been correctly set.
12.2
Setting the excess temperature
The cut-off point is set with the excess temperature dial 5
with a rough scale of temperature values arranged around
it. This scale, of course, can only serve as an approximate
setting means for this cut-off point. However, the cut-off point
can be determined to act exactly if the following procedure
is adhered to:
If for instance a bath liquid has a fire point of 60
°
C the unit
should cut off after reaching 35
°
C at the latest:
1
First set the desired set value using keys 6 (+), (–) to
exactly 35
°
C.
2
After the SWB25 has reached this temperature, turn
the excess temperature dial 5 backwards very slowly
(to the left) until the unit cuts off (acoustic signal, fault
message).
3
Starting the unit after the heat transfer liquid has cooled
down somewhat.
4
Then set the set temperature to the actual temperature
(< 35
°
C).
⇒
The unit can now be used for temperatures below
35
°
C. As soon as 35
°
C is reached, it is securely
switched off.
