Basic Documentation

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Siemens Modular Heating Controller RMH760B CE1P3133en
Building Technologies 6 Boiler temperature control 2017-09-29
When the actual flue gas temperature lies 5 K below the maximum value, the fault
status message can be reset by making an acknowledgement. When resetting, the
slave pointer value is also reset to the current value.
Main menu > Commissioning > Settings > … or
Main menu > Settings > Boiler > Fault settings > Flue temp supervision
Operating line
Range
Factory setting
Impact of fault
No stop / Stop
No stop
Fault priority
Urgent / Nonurgent
Nonurgent
When a flue gas limit temperature is monitored, it can also be determined whether
crossing of the limit value shall cause the boiler to shut down (No stop / Stop).
Main menu > Boiler > Inputs/setpoints
Operating line
Adjustable values / display / remarks
Flue gas temperature
Flue gas temperature maximum
The current flue gas temperature and the maximum flue gas temperature are available
as diagnostic values.
6.8 Flue gas measuring mode
Flue gas measuring mode can be triggered either via a digital input (…Inputs > Flue gas
measuring mode) or operation.
Main menu > Boiler > Flue gas measuring mode
Operating line
Range
Factory setting
Preselection
Off / On
Off
Flue gas meas mode contact
0 / 1
Release stage 2/modulation
Yes / No
Yes
Actual value boiler temperature
Flue gas temperature
When the flue gas measuring mode is activated, boiler pump and peripheral devices
will be put into operation. The boiler is assigned a boiler temperature setpoint of 90 °C.
This value is limited by the maximum boiler temperature.
During the time the flue gas measuring mode is active, supervision of the maximum
permissible flue gas temperature will not lead to a plant stop. However, should the
maximum permissible flue gas temperature be exceeded, a fault status message will be
displayed.
The function will automatically be ended after 30 minutes.
6.9 Boiler faults
If a boiler initiates lockout, it will be shut down until the fault is rectified.
A boiler is considered faulty if one of the following faults occurred:
• Burner fault
• Boiler pump fault
• Fault of shutoff valve (no checkback signal)
• Maximum permissible flue gas temperature exceeded (if plant stop is required)
• One of the 3 digital fault inputs indicates a fault
• Faulty boiler temperature sensor
Supervision of maximum
value and boiler stop
Diagnostic values