73
5.1.7. Trip counters for circuit-breaker condition monitoring
The trip counters for circuit-breaker condition monitoring provide history data,
which can be used for circuit-breaker service scheduling. With this information, the
service cycle can be estimated for the future.
The monitoring function consists of four counters, which count the number of trip
signals generated to the circuit breaker by the relay. Every time a stage generates a
trip signal, the corresponding counter value is increased by one. The number of trips
is stored in the non-volatile EEPROM memory.
There are separate counters for the different protection stages because breaking the
current in different fault situations wears the circuit breaker differently. Each
overcurrent stage (I>, I>> and I>>>) has its own trip counter, whereas there is a
common trip counter for stages I
0
>, I
0
>>, ΔI>, θ>, ARC and the external trip.
The counters can be read via the HMI or SPA parameters V9...V12 and cleared via
SPA parameter V166. When a counter reaches its maximum value, it rolls over.
In case several stages trip during the same fault sequence, only the
counter of the stage which tripped first is increased by one.
5.1.8. Indicator LEDs and operation indication messages
The operation of the relay can be monitored via the HMI by means of LED
indications and text messages on the LCD. On the front panel of the relay there are
three indicator LEDs with fixed functionality:
*
Green indicator LED (ready)
*
Yellow indicator LED (start/alarm)
*
Red indicator LED (trip)
In addition, there are eight programmable LEDs and an indicator LED for front
communication. Refer to the Operator’s Manual for a more thorough presentation.
The indication messages on the LCD have a certain priority order. If different types
of indications are activated simultaneously, the message with the highest priority
appears on the LCD.
The priority order of the operation indication messages:
1. CBFP
2. Trip
3. Start/Alarm
5.1.9. Demand values
The relay provides three different kinds of demand values.
Feeder Protection Relay
Technical Reference Manual
REF 610REF 610
1MRS755310
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