25
Operation PC 20 to 32 kW
2011-12
Overtemperature, safety temperature limiter
Pump safety run,
Automatic heat dissipation at overtemperature
If the
boiler temperature
exceeds 90°C
(factory
setting) for any reason, the
pump safety run
will
start. All heating pumps and boiler pumps that are
connected to the boiler control are switched on to
dissipate heat from the boiler.
This action prevents the boiler temperature from
rising further and triggering further safety devices
such as: safety temperature limiter and thermal
emergency cooling valve. This emergency cooling is
shown on the monitor
"Emergency cooling"
.
The
heat dissipation
is limited with the
maximum
fl ow temperature set in the heating circuits
and
the
hot water setpoint temperature
.
Safety shutdown by safety temperature limiter
For additional safety against boiler overheating, a
safety temperature limiter
is built into the boiler.
When a
boiler temperature of 100°C
(tolerance
97 to 103°C) is reached, the
power supply to the
draught fan and the fuel intake is interrupted
.
If the boiler temperature decreases
below 70 °C
again, the
safety temperature limiter
can be
manually released
for a restart of the boiler.
Overtemperature, safety temperature limiter
STB