Commissioning; General; Wiring; Insulation - GE MVAX 11 Technical Manual

R8010RB
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2.

COMMISSIONING

2.1

General

Before leaving the factory all relays are accurately adjusted, tested and carefully packed.
Hence there should be no need for any re-adjustment on commissioning.
Moving parts are held in position during transit by rubber bands and packing.
These should be removed carefully.
To gain access to the relay first loosen the captive cover screws. Then carefully remove the
cover from the case.
The module can then be removed from the case by grasping the handles at the top and
bottom of the front plate and pulling forwards.
Care must be taken to ensure that mechanical settings of the element are not disturbed.
Carefully remove the rubber band securing the flag mechanism.
Check that the ends of the push rods are located in the holes in the contact springs.
Carefully actuate the armature of each unit in turn with a small screwdriver/probe.
Note immediately after the point where any make contacts just close there is a further small
movement of the armature. This ensures that contact follow through and wiping action is
present. Repeat similarly with break contacts on armature release.
On units fitted with hand reset flag indicators, check that the flag is free to fall before, or just
as, any make contacts close.
Replace the module in the case and refit the cover. Make sure that the reset mechanism in
the cover is correctly located with respect to the relay element, and that the flag (or
mechanism) can be reset.
2.2

Wiring

Check that ratings of the relay agree with the supplies to which it is to be connected.
Check all wiring connections to the relay, including the case earthing connection above the
terminal block. It is especially important that dc supplies are wired with the correct polarity.
The relay diagram number appears inside the case.
2.3

Insulation

The relay, and its associated wiring, may be insulation tested between:
a) all electrically isolated circuits
b) all circuits and earth
An electronic or brushless insulation tester should be used, having a dc voltage not
exceeding 1000V. Accessible terminals of the same circuit should first be strapped together.
Deliberate circuit earthing links, removed for the tests, subsequently must be replaced.
2.4 MVAX 11
With MVAX 11 relays check that all wiring complies to the appropriate application diagram to
ensure that the relay is wired correctly.
2.5 MVAX 12
With MVAX 12 relays, check that terminal 13 of the relay case is wired to the POSITIVE of
the trip supply.
Service Manual
MVAX