Operating instructions

7 Safety devices
The oven can be equipped with an adjustable overheat controller (TWW), class 3.1 or
adjustable temperature limiter (TWB), class 2. Both work independently of the
temperature control system according to DIN 12880. By different adjustments, those
safety devices can have two different functions:
o Protection of oven and environment and additionally
o Protection of the load from excessive temperature
The safety devices should be checked at regular intervals, e.g. once a month, once the
oven has stabilised at the desired temperature. To perform this safety check, reduce the
setting of the safety device until the red control light at the main switch module turns on.
After that, the safety device can be set again.
i
150°C
working
temperature
^ safety temperature
(
t
Notice:
During operation the safety device has to be set
sufficiently higher than the maximum working
temperature or at the maximum temperature of
the oven.
7.1 Adjustable overheat controller (TWW), class 3.1 according to DIN 12880
Protection of oven and environment:
o Turn the adjustable overheat controller e.g. by
use of a coin to upper temperature limit.
Protection of load:
o First turn adjustable overheat controller to upper
limit,
o After the oven has stabilised, the setting of the
overheat controller should be moved down until
it operates.
Upper
temperature
limit:
Protection of
oven and
environment
Set close to
the switching
point:
Protection of
the load
I 0 ©
o The red signal lamp in the main
switch module turns on.
o Now turn back the overheat controller to nearly
one digit higher.
Maximum temperature rating of oven
one scale line means approx.
220°C
15°C
UM 200-800/SM 200-400, ULM/SLM 400-800