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DRAWOUT RELAYS, GENERAL
S i nce a l 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 o r an equi val ent s teel case.
ma gnet i c e ffects of the encl osure wi l l be accuratel y dupl i ca ted dur i n g testi n g.
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.
T h i 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. T he 1 2XLA1 2A test pl ug may al so be used.
a l l ows greater tes t i n g fl e x i b i l i ty, i t requi res CT s ho rt i ng jum pers a n d the exerc i s e
o f greater care, s i n ce connec t i o n s a re m a d e t o both the rel ay a n d the e xtern al
c i rcui try.
POWER REQU I REMENTS, GENERAL
Al l al terna t i n g current o perated dev i ce s are a ffected by frequency.
s i nus o i dal wavefo rms can be anal yzed a s a fundamental frequency pl us h a rmo 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 ) w i l l
be a ffected by the a ppl i ed wav e fo rm.
Therefore, i n order to test a l tern at i n g current rel ays pro perl y i t i s e s s en t i al
to use a s i ne wave o f current a n d/or vol ta ge.
i ts
freedom from harmon i cs ) cannot be expressed a s a
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, o r
s a tura t i n g el ectroma gnets ( suc h a s t i me ove rcurrent 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 s ea l - i n un i t has an o pe rati 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 o n 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
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 ea l - i n t a p s c rew i s the s c rew hol d i n g the r i ght- hand s ta t i onary contact o f
t h e seal - i n un i t.
Then take a s c rew from the l eft- hand s tati onary contact and pl ace i t i n the d e s i red
ta p.
Ne xt, remove the s c rew from the other ta p and pl ace i t back i n the l eft- hand
contact.
Th i s procedure i s neces s a ry to preven t the r i ght- hand stati onary contact
from gett i n g out of a djus tment. Ta p screws s houl d
same ti me.
1.
Connect rel ay s tuds 1 and 1 1 or 1 a n d 12 ( see i nternal connec t i 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.
2.
C l ose or jum per the contact ( s ) that pa ral l el the s eal - i n un i t contact.
3.
I ncrea s e the current sl owl y unt i l the seal - i n un i t pi cks up. See Ta bl e 1 1.
4.
Open the pa ral l el contact c i rcui t o f 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.
5.
Decrea s e the current s l owl y unt i l the seal - i n un i t dro ps out.
1 1.
GEK-49848A
To change t h e ta p sett i n g, fi rst remove the connec t i n g pl ug.
The puri ty o f the s i ne wave ( i .e.,
1 -
i n ta p s c rew s houl d be set i n
be l eft i n
never
1 6
I n t h i s way, any
Al though t h i s t e s t pl ug
S i nce non
fi n i te number for any
both
ta ps a t the
See Tabl e
A
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