Power Req U I Rements, Genera L; Pickup Vo Ltage Test; Ti M E-Vo Ltage Test - GE IAV51A Instructions Manual

B . Powe r Req u i rements, General
A l l d evices operati ng on a lternating cu rrent {AC) a re affected by fre q u e ncy. Si n ce
n o n -s i n usoid a l wavefo rms can be a n a l yzed as a fu n d a m e n ta l f re q u e n cy p l u s
h a rmon ics of that fu ndamenta l freq uency, it fol l ows that a lte rnating-cu rrent d evices
{ re lays) wi l l be affected by a p p l i ed waveforms. AC rel ays {and AC d evices i n g e n e ra l )
a re s i g n i ficantly affected by the appl ication of non-si n usoi d a l wavefo rms.
Therefore, in o rd e r to test AC relays pro perly it is esse ntial to use a test volta g e a nd /o r
cu rrent wavefo rm that is sin usoid a l . The pu rity o f the sine wave { i . e . , its freed o m
from h a rm o n i cs) ca n not b e expressed a s a fin ite n u mber fo r a n y particu l a r relay;
h ow e v e r , a n y re l a y u s i n g t u n ed c i rc u i ts, R L or RC n etwo r k s , or s a t u r a t i n g
e lectro m a g n ets {such as time-ove rcu rrent relays) wou ld be espec i a l l y affected by n o n ­
si n usoidal wave forms.
S i m i l a rly, rel ays req u i ri n g DC control power should be tested usi n g DC power a n d not
fu l l wave rectified power. U n l ess the rectified su pply is wel l fi ltered , m a n y re lays w i l l
n ot o pe rate p roperly d ue to the d i ps i n the recti fi ed powe r.
exa m ple, ca n tu rn off d u ri n g th ese d i ps. As a genera l ru le, the DC so u rce s h o u l d n ot
conta i n more th a n 5% ripple.
C.
T h e pick u p voltage should be checked on one or more taps o n re lays t h at cl ose
contacts on i n creas i n g voltage. The pickup vo ltage sho u l d be ta p va l ue
d ro p-out voltage should b e ch ecked on o n e or more ta ps on re lays that cl ose co ntacts
on d ecreasi ng voltage. The d ro pout vo ltage is a va ri a b l e d e pend i n g u po n u s e r
req u i reme nts.
A DJ U STM E NTS .
{closi n g voltages, rig ht or left contact) .
D.
The time/voltage cu rves should be checked for one or more setti ngs.
Reco m m ended test con n ections for the above test a re shown in Fi g u re 1 7 fo r the
overvolta g e re l a ys, such as th e Types I AV 5 1 A a n d I A V 5 2 A .
overvolta g e relays, such as the Types IAV53A, IAV5 3 B , IAV53C, I A V 5 3 D , I A V5 3 K,
IAV53 L , IAV5 3 M and IAV53N, ca n be checked fo r time of clos i n g left contacts b y usi n g
co n n ections shown i n Fi g u re 1 7, and for cl osi ng right contacts by con n ectio n s s h ow n
i n F ig u re 1 8. O f cou rse t h e sea l-i n u n it shown i n the fi g u re is n ot used i n the case of
the IAV53 B a n d IAV53D, but a l l stud n u m bers a re correct fo r th ese relays.
Stud n u m bers 1 and 2 should be su bstituted for stud n u mbers 9 a n d 1 0 o n F i g u re 1 8
for testi n g the u nd e rvoltage co ntacts of the Type IAV53C rel ay {See i ntern a l d ia g ra m ,
Fi g u re 5) . See i nte rnal con n ections, Fi g u res 1 -5 fo r contact a n d co i l con necti o n s fo r
IAV5 1 A, IAV52A, IAV53A, B, C
IAV53 N .
G E H - 1 81 4
Refer to t h e VO LTA G E S ETT I N G sect i o n u nd e r
See re lay nameplates for va l u es of p i ck u p o r d ro p o u t voltages
&
D and Fig u res 6 - 8, for IAV5 3 K, IAV53 L, IAV53M a nd
1 0
Z e n e r d i od es, for
±
5 % . T h e
S E R V I C I N G A N D
T h e u n d e r- a n d