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Operation
indicators
Fault codes
ABB Automation
A measuring relay module is provided with two
separate operating stages, each of which with its
own yellow/red operation indicator on the lower
part of the front plate of the relay module.
In addition to the protective functions the relay
module is provided with a self-supervision sys-
tem which continuously supervises the function
of the microprocessor, its program execution
and the electronics.
When the self-supervision system has detected a
permanent fault in the relay module, the red
IRF indicator on the panel starts glowing soon
after the fault was discovered. At the same time
the module puts forward a signal to the self-
supervision contact of the relay assembly.
The operation indicator starts glowing yellow
when the operating stage starts and red when a
delayed tripping operates. The functions of the
start and operation indicators are described in
detail in the different protection relay module
manuals.
In most fault situations a fault code, indicating
the nature of the fault, appears on the display of
the module. The fault code, which consists of a
red digit (1) and a three digit green code number,
cannot be removed from the display by reset-
ting. When a fault occurs, the fault code should
be recorded and stated when service is ordered.
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