Basic Documentation

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Siemens Modular Heating Controller RMH760B CE1P3133en
Building Technologies 14 Function block faults 2017-09-29
14.5.1 Acknowledgement and reset
No acknowledgement is required for simple faults.
If the outside temperature is missing, a fault status message will be delivered. When
the outside temperature is available again, the fault status message automatically
disappears and the plant will resume normal operation.
These types of fault require an acknowledgement.
If there is more than one time switch master in the same geographical zone, the fault
status message must be acknowledged.
An acknowledgement and a reset required for this type of fault.
If the maximum temperature of flue gas temperature supervision at the boiler has been
exceeded, the fault status message must be acknowledged and, after rectification of
the fault, a reset must be made by pressing the fault button again.
14.5.2 Signal priority
Fault status messages are called "urgent" when correct operation of plant can no
longer be ensured.
An urgent fault status message is a boiler sensor error, for example.
Nonurgent fault status messages
• do not adversely affect plant operation directly
• allow the plant to operate with restrictions
A nonurgent message is an outside sensor error, for example.
14.5.3 Plant behavior
There are:
• Faults with aggregate stop
• Faults without aggregate stop
A fault only acts on the aggregate to which the fault status message belongs. An
exception are the pumps. Failure of a pump also acts on the associated aggregate.
The universal fault inputs only lead to a plant stop in connection with parameterization
"Stop". For more details, refer to section 14.8 " Fault inputs".
Number
Text
Effect
5201
Hol/sp day prgm failure HC 1
Heating circuit 1 performs normal
operation. Holidays and special days are
not possible
5102
>1 time switch in plant 1
The heating circuit runs in room
operating mode Comfort
10
Outside temp sensor error
If available, the outside temperature of
some other zone via bus will be used,
otherwise the backup value of 0 °C
2491
[Main pump B] overload
Changeover to main pump A will take
place, if present, otherwise fault status
message [Main pump] fault will be
delivered
2492
[Main pump] fault
The main controller will be stopped since
there is no flow past the sensor so that
control is no longer possible
Simple fault
Example
Standard fault
Example
Extended fault
Example
Priority "Urgent"
Priority "Nonurgent"
Examples