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Building Technologies
Boiler Sequence Controller RMK770
CE1P3132en
HVAC Products
7 Boiler control
23.04.2009
7.9.10 Protection against pressure shocks
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Boiler … > Limitations
Operating line
Range
Factory setting
Delta boiler temp max (stage 2)
0…10 K
1 K
To prevent pressure shocks in the gas network if stages 1 and 2 switch off at the same
time, stage 2 is already switched off before the maximum boiler temperature is reached
the difference being the setting value “Boiler temp max” stage 2.
When the boiler sequence manager locks a boiler, stage 1 is switched off 10 seconds
after stage 2.
7.10 Minimum limitation of the return temperature
Minimum limitation of the return temperature ensures that the return water entering the
boiler does not fall below the permissible level.
If adherence to a minimum return temperature is required, it can be ensured either with
a bypass pump or mixing valve for maintained return temperature per boiler, a common
mixing valve for maintained return temperature for all boilers, or by restricting heat
consumption.
Limitation of the return temperature with a common mixing valve or with impact on the
consumers is described in subsection 6.6.1 “Common maintained boiler return tem-
perature”.
T
313
2
S
6
8
T
T
31
3
2
S
7
1
T
T
T
T
Minimum limitation of the
return temperature with separate
mixing valve per boiler
Minimum limitation of the return temperature with
common mixing valve
In the case of boilers with bypass pump (boiler pump operating parallel to the boiler), the
required boiler return temperature can be maintained by activating the bypass pump.
TBo
ByPu
TRtBo
The bypass pump can be controlled either according to the acquired return temperature
or – if no sensor is installed – at the same time the burner is running.
Normally, the return temperature sensor is installed upstream of the bypass pump to
prevent the pump from cycling.
Maintained boiler
return temperature
with bypass pump
