GEH-1814
CAUTI ON
EVERY CI RCU IT I N THE DRAWOUT CASE HAS AN AUX I L I ARY BRUSH . IT I S ESPECIALLY I MPORTANT ON CURRENT
CI RCU ITS ANU OTHER C I RCUITS WITH SHORT I NG BARS THAT THE AUX I L IARY BRUSH BE B ENT H IGH ENOUGH TO ENGAGE THE
CONNECT I NG PLUG OR TEST PLUG BEFORE THE MAI N BRUSHES DO . TH I S WILL PREVENT CT SECONDARY C I RCU ITS FROM
B E I NG OPENED .
�!ECHAN I CAL INSPECT I ON
1 . On rel ays wh i ch have time d i a l s , the d i a l s wi l l be set a t zero before the rel ay l eaves the factory .
I t i s necessary to change th i s setti ng i n order to open the rel ay contacts .
2 . On a l l rel ays wi th l ocked time di al s , make sure the two time-d i a l l ock i ng screws are ti gh t . These
l ocki ng screws are to prevent the di a l from mov i ng when the rel ay i s s ubjected to h i gh operati ng torque.
3 . The movi ng contact shoul d be fas tened securely i n i ts support and shou l d engage the s tationa ry contact
about i n the mi ddl e or at l east 1 / 1 6 i nch i ns i de the peri phery of the s tati onary contact .
4 . The s top arm l eaf s pri ng shoul d defl ect about l /64 i nch and the s top arm shou l d cl ear the mol ded bl ock
by at l east . 02 0 i nc h .
5 . Any fore i g n materi al mus t b e cl eaned out o f s tator a i r gaps . Cl earance between the d i sk and ei ther
the drag mag�et or U-magne t shou l d be a t l east 0 . 0 1 0 i nch for any pos i ti on of the di sk .
6 . E nd pl ay of the di sk shou l d be from 0 . 005 i nch to 0 . 0 1 0 i nch . End pl ay shou l d not be so g reat as to
al l ow the d i s k to s tri ke the U-magnet or the drag magnet. Check that top and bottom pi vot and beari ng
screws are tight.
7 . There shoul d be no noti ceab l e fri cti on in the rotati ng s tructure .
8 . Rotate the time d i a l to the zero pos i ti o n . Check by means o f a neon l amp tha t the contacts j u s t cl ose .
There shou l d be approxima tel y 1 /32 i nch wi pe on the s ta ti onary contact . I f the contact does not
c l os e , adjust the d i s k pos i tion by backi ng off the two cl amp i ng screws on the stop arm and rota ti ng
the stop arm rel ati ve to the cu tout i n the di s k . Th i s provi des a coarse adjustment . Reti ghten the
c l ampi ng screws .
For fi ne adjus tment of contact c l os i ng , run the stati onary contact b rush i n or out by means of i ts
adj usti ng screw ; after thi s adj us tmen t , check that the screw i s he l d fi rml y i n i ts support .
9 . On doubl e- throw rel ays , the support pos t of the upper spri ng shoul d cl ear the i nsul ati ng pl ate by at
l east 1 /64 i nch .
ELECTRI CAL TESTS
A. DRAWOUT RELAYS GENERAL
Si nce al l drawout rel ays i n serv i ce operate i n thei r cases , i t i s recommended that they be tes ted i n
thei r cases or a n equ i va l ent s teel . cas e . I n th i s way any magneti c effects o f the encl osure wi l l b e
accura tel y dupl i cated duri ng tes ti n g . A rel ay may be tes ted wi thout remo v i ng i t from the panel b y usi ng
a 1 2XLA1 3A tes t pl ug . Th i s pl ug makes connecti ons onl y wi th the rel ay a nd �oes not di s turb any shorti ng
bars i n the cas e . O f course , the 1 2XLA1 2A test pl ug may al so b e used . Al though thi s tes t pl ug a l l ows
greater testi ng fl exi b i l i ty , i t al so requi res CT s horti ng j umpers a nd the exerci se of g reater c a re s i nce
connecti ons are made to both the �el ay and the external c i rcui try .
B . POWER REQU I REMENTS GENERAL
Al l al ternati ng-current operated devi ces are affected by frequency . Si nce non-s i nusoi dal waveforms
can be anal yzed as a fundamental frequency pl us harmoni cs of the fundamental frequency , i t fol l ows th at
al ternati ng-current devi ces ( re l ays ) wi l l be affected by the appl ied waveform .
Therefore , i n order to properly tes t al terna ti ng-cu rrent rel ays i t i s essenti al to use a s i ne wave
of current and/or vol tage . The puri ty of the s i ne wave ( i . e . i ts freedom from harmoni c s ) �annot be
expressed as a fi ni te number for any parti cul ar rel ay , however , any rel ay us i ng tuned c i rcu i ts , R-L or
RC networks , or satura ti ng el ec tromagnets ( s uch as time-overcurrent rel ays ) woul d be essenti a l l y affected
by non - s i nusoi dal wave forms .
Simi l ar l y , rel ays requ i ri ng d-e control power shoul d be tested us i ng d-e power and not ful l wave
rec ti fi ed power. Unl ess the recti fi ed s upply i s we l l fi l tered , many rel ays wi l l not operate properl y due to
the d i ps i n the recti fied power . Zener d i odes , for exampl e , . can turn off duri ng these d i ps . As a genera l
rul e the d - e source shoul d not conta i n more than 5 percent ri ppl e .
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