Application - GE SBC23A Instructions Manual

Tabl e I bel ow l i s t s the combi n ed o v e ra l l l o g i c a nd exte rnal c o n n ect i on s di a g rams and
add i t i onal fea t u res o f each rel ay:
Rel ay Model
SB C23A
SBC23B
SB C2 3 C
Note t h a t the S B C2 3 A i ncl u des t h e addi t i on a l non - i s o l a ted c o n ta c t o n t h e IT u n i t
wh i c h i s norma l l y c o n n ec t ed to pro v i de a s e a l - i n a ro u nd t h e i n i t i a t i n g c o n tacts
( B FI, 62X o r 6 2 Y ) .
mode l s, a n d i f u s ed, t h e n o rma l l y- i so l a ted I T c o n ta c t i s no l o n g e r i sol a ted.
Under n o rmal cond i t i on s, t h e SB C rel ays do no t have D C appl i ed.
norma l l y i mmune to any respo n s e to e n v i ronme n ta l
appl i ed v i a B FI o r 62X fu n c t i ons o n l y when a fau l t occ u rs o n a l i n e a s so c i a ted w i th
t h e breaker be i n g pro tec ted.
The powe r s uppy i n t h e s e rel ays i s so des i gned that t h e DC v o l ta ge mu s t exceed 6 0%
o f t h e nomi n a l vol tage ra t i n g i n orde r for the re l ay to ope ra te.
pre v e n t s fa l se t r i ps from c apac i ta nce di s c h a rge o r from t h e vol ta ge -di v i de r e ffec t
o f the g ro u nd-fa u l t l amps on t h e DC bus i n t h e e v e n t tha t t h e DC i np u t termi na l o f
t h e S B C i s acc i dental l y grounded.
The Type S B C s ta t i c breake r-fa i l u re rel ays a re i n tended fo r appl i ca t i o n on a pe r
bre ake r ba s i s . That i s, t h e re i s o n e bre ake r- fa i l u re re l ay a s soc i a ted w i t h eac h
b reake r i n a b u s a r ray.
mu s t come from c u rre n t
a s soc i a ted breaker.
tra ns fe rred tr i pp i n g ) o f a l l breake rs n ec e s s a ry to cl e a r t h e fa u l t upo n fa i l u re o f
t h e breaker a s soc i a t ed w i th t h e SB C rel ay.
a nd bre ake r a r ra ngemen t.
The l i s t i n g i n Ta bl e II c o v e r s t h e bu s a r ra ngeme n t s t h a t a re i n commo n u s e.
a re the s i n g l e-b u s s i n g l e -breaker,
a nd r i n g bus a rra ngemen t s, s hown
l i st i n g i n Tabl e II i nd i ca tes t h e a ss umed fau l t l oca t i on,
a s s umed to h a ve fa i l ed, t h e c o n ta c t i n i t i a t i on t h a t a c t i v a te s t h e S B C, a nd wh i c h
breakers o r l ock-o u t rel ays s h o u l d be tr i pped by the B FT c o n tac ts.
a s i n g l e-bu s s i n g l e -breake r
pro tec ted, the S B C rel ay rec e i v e s t h e c u r re n t a s soc i a ted w i th breaker #2.
co n tac t i n i t i a t i on is from t h e pro tec t i ve r e l ays o f l i ne B.
a faul t a t Fl , t h e S B C rel ay opera tes a nd the B FT c o n t a c t #1 t r i ps t h e b u s l oc ko u t
re l ay.
Fo r a no t h e r exampl e, c o n s i de r t h e r i n g bus a r ra ngeme n t t h a t i s s hown i n
F i g u re 8. I f breaker #1 i s to be protec t ed, t h e S B C re l ay rece i v e s t h e c u r ren ts
GEK-45464
TABLE I
External Conn ec t i ons
a nd Lo g i c D i a g ram
F i g u re 2
F i g u re 3
F i g u re 4
Th i s s e a l - i n conta c t i s opt i o n a l

APPLICATION

On th i s bas i s, t h e c u rren t i nputs to a pa r t i c u l a r SB C rel ay
t ra ns fo rme rs
The t r i p o u tpu ts m u s t be rou ted to i n i t i a te the tr i pp i n g ( or
do ubl e -bus do ubl e-b reake r,
i n F i g u r e s 5 ,
a rra ngement,
Add i t i o n a l Featu res
Seco nd, No n -Iso l a ted
Co n tac t o n IT Un i t
X
Opt i on a l
Opt i o n a l
i n t h e SB C2 3B a n d S B C 2 3 C
e l ec t r i c a l
( CT • s ) t h a t mea s u re
Th i s ro u t i n g w i l l depe nd upon t h e bus
6, 7 a nd 8 re spec t i v el y.
( Fi g u re 5 ) , i f breake r
4
Con tac t
Conv e r te r
X
X
T h u s, t h e S B C i s
tran s i en ts.
DC
Th i s fea t u re
the c u r re n t i n
breake r-a nd-a -ha
t h e b reaker t h a t
F o r exampl e, i n
#2 i s to
If breake r #2 fa i l s fo r
i s
the
They
1
f,
Eac h
i s
be
The
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