GEK-49848A
DRAWOUT RELAYS, GENERAL
S i nce al l drawout rel ays i n s erv i ce o perate i n the i r cases, i t i s recommended
that they be tested i n thei r cases or an equi val ent steel case. I n thi s way, any
ma gnet i c effects of the encl osure wi l l be accuratel y dupl i ca ted duri n g testi n g. A
rel ay may be tested wi thout remo v i n g i t from the panel by us i n g 1 2XLA1 3A test pl ugs.
Thi s pl ug makes connect i ons onl y wi th the rel ay and does not d i s turb any s horti n g
ba rs i n t h e case. The 1 2XLA1 2A test pl ug may al so be used. Al though thi s t e s t pl ug
a l l ows greater tes t i n g fl exi bi l i ty, i t requi res CT s ho rt i ng jum pers and the exerc i se
of greater care, s i n ce connec t i o n s a re made to both the rel ay and the extern al
c i rcui try.
POWER REQU I REMENTS, GENERAL
Al l al terna t i n g current o perated dev i ces are a ffected by frequency. S i nce non
s i nus o i dal wavefo rms can be anal yzed as a fundamental frequency pl us harmo n i cs o f
the fundamental frequency, i t fol l ows that al terna t i n g current dev i ces ( rel ays ) wi l l
be a ffected by the a ppl i ed wavefo rm.
Therefore, i n order to test al ternat i n g current rel ays pro perl y i t i s essen t i al
to use a s i ne wave o f current and/or vol ta ge. The puri ty o f the s i ne wave ( i .e.,
i ts freedom from harmon i cs ) cannot be expressed as a fi ni te number for any
pa rti cul a r rel ay; however, any rel ay us i n g tuned c i rcui ts, RL o r RC networks, or
saturati n g el ectroma gnets ( suc h as t i me overcurrent rel ays ) i s a ffected by non
s i nuso i dal wave fo rms.
TARGET AND S EAL- I N UNITS
The target and seal - i n un i t has an o perati ng co i l ta pped a t 0.2 a n d 2.0
amperes.
When used wi th tri p co i l s o pera t i n g on currents ran gi n g from 0.2 to 2.0 amperes
at the m i n i mum control vol ta ge, the target and sea
1-
i n ta p screw s houl d be set i n
the 0.2 ampere ta p. When the tri p co i l current ran ges from two to 30 amperes at the
m i n i mum control vol ta ge, the ta p s crew s houl d be pl aced i n the 2.0 ampere t a p.
The s eal - i n t a p screw i s the screw hol d i n g the r i ght- hand stati onary contact of
the seal - i n un i t.
To change the ta p sett i n g, fi rst remove the connec t i n g pl ug.
Then take a screw from the l eft- hand stati onary contact and pl ace i t i n the desi red
ta p. Ne xt, remove the screw from the other ta p and pl ace i t back i n the l eft- hand
contact. Th i s procedure i s necessary to prevent the ri ght- hand stati onary contact
from gett i n g out of adjus tment. Ta p screws s houl d
never
be l eft i n
both
ta ps a t the
same ti me.
and
Tests
1.
2.
3.
4.
5.
Connect rel ay s tuds 1 and 1 1 or 1 and 12 ( see i nternal connecti ons d i a gram )
to a DC source, ammeter and l oad box so that the current can be control l ed
over a ran ge o f 0.1 to 2.0 amperes.
Cl ose or jum per the contact ( s ) that pa ral l el the seal - i n un i t contact.
I ncrea se the current sl owl y unt i l the seal - i n un i t pi cks up. See Ta bl e 1 1.
Open the pa ral l el contact c i rcui t of s tep 2; the seal - i n un i t s houl d rema i n
i n the pi cked up pos i ti on.
Decrea se the current s l owl y unti l the seal - i n un i t dro ps out. See Tabl e
1 1.
1 6
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