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Building Technologies
Boiler Sequence Controller RMK770
CE1P3132en
HVAC Products
12 Function block faults
01.03.2005
If a plant uses more than 1 time switch master in the same geographical zone, this fault
status message must be acknowledged.
There is an acknowledgement and a reset required for this type of fault.
If both pumps of the twin pump signal a fault, the fault status message must be ac-
knowledged and – after correction of the fault – be reset by pressing the fault button a
second time.
12.4.2 Signal
priority
Fault status messages are called urgent when correct operation of plant can no longer
be ensured.
For example, “Error boiler temperature sensor” would be an urgent fault status mes-
sage.
Nonurgent fault status messages
•
do not adversely affect the plant operation directly
•
allow plant to operate with restrictions
A nonurgent fault status message would be “Loss of outside temperature“, for example.
12.4.3 Plant
behavior
There are:
•
Faults with plant stop or aggregate stop
•
Faults without plant stop or aggregate stop
Whether a fault leads to an aggregate stop (e.g. shutting boiler down and deactivating
pumps) or a plant stop (shutting all boilers down) depends on the type of fault.
Faults of a boiler or faults of a boiler pump also lead to shutdown of the relevant boiler.
A fault of the boiler sequence manager can cause the entire multiboiler plant to shut
down.
The universal fault inputs only lead to a plant stop if “Stop” is parameterized.
Number Text
Effect
5201
Hol/spec day program
failure
Nonurgent message; must not be ac-
knowledged
5102
>1 time switch in plant 1
Nonurgent message; must be acknowl-
edged
10
Outside temp sensor
error
Nonurgent message; must not be ac-
knowledged
2491
[Main pump B] overload
Contact overload B active.
Nonurgent message; must be acknowl-
edged
2492
[Main pump] fault
Both overload contacts of the twin pump
are active.
Urgent message; must be acknowledged
and reset
Example
Acknowledgement and
reset (extended fault)
Example
Priority urgent
Priority nonurgent
Examples