Connecting Optical Fibre Cables For The Longitudinal Differential Protection; Commissioning Tests - ABB REG316 4 Series Operating Instructions Manual

REG 316*4 1MRB520049-Uen / Rev. C
7.3.5. Connecting optical fibre cables for the longitudinal differen-
tial protection
Optical fibre cables are connected using Type FC connectors.
Take care when inserting the connectors that only to tighten
the screw fitting after checking that the nose on the plug is
properly seated in the groove of the base.
To exclude any risk of false tripping when connecting or discon-
necting a cable in operation, only do so after the auxiliary supply
to at least one of the terminal units has been switched off.
In cases where the terminal units are connected via communica-
tions devices such as FOX-U, ensure that the communication in
both directions is via the same route (equal lengths).
7.3.6.

Commissioning tests

For the protection scheme as a whole to operate correctly, it is
not enough for just the protection equipment itself to be in order,
the reliable operation of the other items of plant in the protection
chain such as circuit-breakers, c.t's and v.t's (e.g. protection and
metering core leads exchanged), station battery (earth fault),
alarm and signalling circuits etc. and all the cabling is equally
important.
The correct operation of the equipment itself is determined by
the following tests:
· secondary injection of every current and voltage input
· activating and deactivating every binary input (opto-coupler)
· energising and de-energising every auxiliary tripping and sig-
nalling relay
· checking the settings (printed by the HMI).
These tests confirm that none of the protection hardware is de-
fective. The actual protection functions are contained in the soft-
ware and are continuously monitored. They do not therefore
need to be especially tested during commissioning.
The following is a list of some of the tests and the faults they are
intended to disclose.
ABB Switzerland Ltd
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