Protection Against Pressure Shocks; Minimum Limitation Of The Return Temperature - Siemens Synco700 RMK770 Documentation Handbook

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7.9.10 Protection against pressure shocks

Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler ... > Limitations
Operating line
Delta boiler temp max (stage 2)
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 boiler return temperature is part of the boiler's protective
functions. Minimum limitation of the return temperature ensures that, by the boiler inlet
also, the temperature will not drop below the permissible value.
If minimum limitation of the return temperature is required, it can be provided either by a
separate mixing valve for the maintained boiler return temperature per boiler, a com-
mon mixing valve for the maintained boiler return temperature of all boilers, or by re-
stricting the amount of heat drawn by the consumers.
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
T
Minimum limitation of the
return temperature with sepa-
rate mixing valve per boiler
If minimum limitation of the return temperature shall be provided with a mixing valve per
boiler, that mixing valve must be configured. With plant types K6.x, that mixing valve
with a 3-position actuator is preconfigured; with the other types of plant, the mixing
valve and the return temperature sensor can be added in the extra configuration.
Main menu > Commissioning > Extra configuration > Boiler ... > Outputs
Operating line
Maint boiler return temp 3-pos
Maint boiler return temp mod
Main menu > Commissioning > Extra configuration > Boiler ... > Inputs
Operating line
Return temperature sensor
Boiler Sequence Controller RMK770
7 Boiler temperature control
Range
0...10 K
T T
T
Minimum limitation of the return temperature with
common mixing valve
Adjustable values / remarks
Assign output
Assign output
Adjustable values / remarks
Assign input
Factory setting
1 K
T
T
CE1P3132en
01.03.2005