Instantaneous Unit; Contact Cleaning; Reneyal Parts - GE IBCG51M A Series Instructions Manual

Ground directional overcurrent relays
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'in the range of 5 to 25 amperes. A screw projecting from the side of the moving contact
arm controls the clutch pressure.
voltage.
With suddenly applied current, adjust the clutch so that it will not slip at
ten amperes or less, but will slip at or above 15 amperes. This setting,
is tighter than the 8-18 ampere acceptance test limit and is intended to assure that
the acceptance test limits will be met in any future tests.

INSTANTANEOUS UNIT

1. Both contacts should close at the same time.
2. The backing strip should be so formed that the forked end (front) bears against the
molded strip under the armature.
3. With the armature against the pole piece, the cross member of the "T" spring should
be in a horizontal plane and there should be
Check this by inserting a
shaded pole with the armature held closed.
feeler gage in place.
Contact Cleaninq
For cleaning fine silver contacts, a flexible burnishing tool should be used. This
consists of a flexible strip of metal with an etched roughened surface, resembling in
effect a superfine file.
left, yet corroded material will be removed rapidly and thoroughly. The flexibility of
the tool insures the cleaning of the actual points of contact.
Fine silver contacts should not be cleaned with knives, files or abrasive paper or
cloth.
Knives or files may leave scratches which increase arcing and deterioration of
the contacts.
Abrasive paper or cloth may leave minute particles of insulating
abrasive material in the contacts, thus preventing contact closing.
The burnishing tool described above can be obtained fras the fa&tory.
is recommended that sufficient quantities of renewal parts be carried in stock
It
to enable the prompt replacement of any that are worn, broken or damaged.
When ordering renewal parts, address the nearest Sales Office of the General
Electric Company, specify quantity required, name of part wanted, and give complete
nameplate data.
If
which the relay was furnished.
Use rated frequency and current in phase with the
inch feeler gage between the front half of the
0.010
The polishing action is so delicate that no scratches are
RENEWAL
possible, give the General Electric Company requisition number on
Refer to renewal parts publication GEF-4083.
at least1/64
The contacts should close with the
PARTS
23
amperes,
inch wipe on the contacts.

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