(
Gt:K-45376
A l l the tests described above under IN STALLAT ION TESTS must be performed at the time of instal l ation .
In addition, if those tests described under the ACCE PTANCE TEST S section were not performed prior to
insta l l ation, it is recommended they be performed at this time.
High Dropout Instantaneous Unit
1 . Sel ect the desired range by setting the movab l e l ead in the proper position . ( See Figure
2
and
the interna l connections diagram ) . Whenever possib l e a l ways se lect the higher range since it has
higher continuous rating .
2.
Set the hioh dropout instantaneous unit to pick up at the desired current l eve l . See SETT I NG THE
HIGH DROPOUT I N STANTANEOUS UNIT in the ACCEPTANCE TEST section.
A l l the tests described above under I N STALLAT ION TESTS must be performed at the time of insta l l ation .
In addition, if those tests described under the ACCEPTANCE TESTS section were not performed prior to
t
insta l lation, it is recommended they be performed at this time.
t
*
PER I O D I C C HECKS AND ROUT I NE MA I NTENANCE
In view of the vita l rol e of protective rel ays in the operation of a power system it is important that
a periodic test program be fol l owed . It is recognized that the interva l between periodic checks wi l l vary
depending upon environment, type of rel ay and the user's experience with periodic testing. Until the user
has accumul ated enough experience to sel ect the test interval best suited to his individua l requirements
it is suggested that the points l isted bel ow be checked at an interval of from one to two years.
These tests are intended to insure that the re l ays have not deviated from their origina l settings. If
deviations are encountered the re l ay must be retested and serviced as describe9 in this manua l .
TIME OVERCURRENT UNil.
l . Perform pickup test as described in the I NSTALLAT ION section for the tap setting i n service .
2 . Perform the time tests as described in the I NSTALLAT I ON section.
H I -SE I SM I C I NSTANTANEOUS U N I T
l . Check that the instantaneous unit picks up a t the desired current l eve l , as out l ined in the
ACCEPTANCE TEST section.
H I GH DROP OUT I NSTANTANEOUS UNIT
1 . Check that the high drop-out instantaneous unit picks up and drops out at the desired current
l evels, as out l ined in the ACCEPTANCE TEST section.
H I -SE I SM I C TARGET AND SEAL- I N UN IT
l . Check that the unit picks up at the va lues shown in Tab l e 1 1.
2 . Check that the unit drops out at
25
percent or more of tap va lue .
CONTACT CLEA N I NG
For cl eaning re l ay contacts, a f l exib l e burnishing.too
�
shoul d be used . . This.consists of� f
�
exibl e
strip of meta l with an etched-roughened surface resembl 1ng 1n effect a superf1ne f1l e. The po l 1sh1ng
.
action is so de l icate that no scratches are l eft, yet it wi l l c l ean off any corrosion thorough ly and rap1dl y .
Its f l exibi l ity insures the c l eaning of the actua l points of contact. Do not use knives, fil es, abrasive
paper or cl oth of any kind to cl ean rel ay contacts.
COVER C LEAN I NG
The l exan** cover shoul d 'on l y be cleaned with soap and water . If sol vents are used that contain hydro
carbons, then the cover may become c l oudy.
SYSTEM TEST
A l though this instruction book is primari l y written to check and set the I FC rel ay, overa l l functional
tests to check the system operation are recommended at interva l s based on the customer's exper ience .
* indicates revison
13
**registered trademark of Genera l E l ectric Company
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