15
Operation
indication
Fault codes
A relay module is provided with a multiple of
separate operation stages, each with its own
operation indicator shown on the display and a
common trip indicator on the lower part of the
front plate of the relay module.
The starting of a relay stage is indicated with one
number which changes to another number when
the stage operates. The indicator remains glow-
ing although the operation stage resets. The
In addition to the protection 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.
Shortly after the self-supervision system detects
a permanent fault in the relay module, the red
IRF indicator on the front panel is lit . At the
same time the module puts forward a control
signal to the output relay of the self-supervision
system of the protection relay.
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 figure "1" and a three digit green code
number, cannot be removed from the display by
resetting. When a fault occurs, the fault code
should be recorded and stated when service is
ordered. When in a fault mode, the normal
relay menus are operative, i.e. all setting values
and measured values can be accessed although
the relay operation is inhibited. The serial com-
munication is also operative making it possible
to access the relay information also from a
remote site. The internal relay fault code shown
on the display remains active until the internal
fault possibly disappears and can also be re-
motely read out as variable V 169.
indicator is reset by means of the RESET push
button of the relay module. An unreset opera-
tion indicator does not affect the function of the
protection relay module.
In certain cases the function of the operation
indicators may deviate from the above princi-
ples. This is described in detail in the descrip-
tions of the separate modules.