GEH-1753 Time Overcurrent Relays Type
IA<.:
CONTACT CLEANING
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. The
polishing action is so delicate that no scratches are
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 and thus prevent
closing.
The burnishing tool described above can
be
obtained from the factory.
PERIODIC TESTING
An operation test and inspection of the relay at
least once every six months are recommended. Test
connections are shown in Fig. 18.
RENEWAL PARTS
It
is recommended that sufficient quantities of
renewal parts be carried in stock to enable the
prompt replacement of any that are worn, broken,
or damaged.
pany, specify quantity required, name of part wanted,
and give complete nameplate data.
If
possible,
give the General Electric Company requisition
number on which the relay was furnished.
When ordering renewal parts, address the
nearest Sales Office of the General Electric Com-
For a recommended parts list refer to Parts
Bulletin number GEF-3883.
.025
_,.Qin
0:: .01
.00 s
14
1.5
2
Ill SEIS41C MTB>·IMSTMTMBIUS •nT
IPERATIMG TIME
a>ERATIN& TIME
RANGE FOR ANY
PICICUP SETIING
3
6
IIIJL fl PlES OF PICKUP
7
8
Fig. 19 (0208A8695
(l])
Time-Current Characteristics for the "Hi-G" Unit
g
Since the last edition, Figures
12
and 14 have been revised.
10
www
. ElectricalPartManuals
. com
