P Er For M A N - Hitachi H20-T Technical Notes

F ig. 13 Oper at in g circu it
2-2 P E RFORMANCE
Th e perform a nce of t h e cont a ct or is gu a r a nt eed by ca rr yin g out a t est u nder t he t est in g con dit ions set for th accor ding
t o t h e sta n dar d a n d sa t isfyin g t he va lue specified t her ein . The test in g condit ion s va r y wit h t h e t ypes of loa ds, wh ich
a r e classified in t o ca t egor ies from AC1 t o AC4 as given in Ta ble 5.
Ca t egor y
AC1
AC2
AC3
AC4
1) By plu ggin g, is u n derst ood st oppin g or reversin g t h e mot or r apidly by r ever sin g m otor pr im ar y
con n ect ions wh ile t he m otor is r un n in g.
2) By in chin g (joggin g), is u n derst ood en er gizin g a m otor on ce or r epea tedly for sh or t per iods to
obt a in sm a ll m ovem ent s of t h e driven m ech a n ism .
Th e m a jor t est it em s to determ in e t h e perform a n ce of t h e con t a ct or a re as follows.
・ Tempera t ur e r ise t est
・ Mak in g a n d br eak in g ca pa cit ies t est
・ Mech a n ica l en dur a n ce t est
・ E lect r ica l en dur a n ce t est
(1) Tem per a t ur e r ise t est
Wh en t he t em per at u r e r ise becom es const an t aft er t he r at ed oper a t ion a l cu r ren t or r at ed t h er m al cur r ent h as flowed
t o t h e ma in circu it a nd a u xiliar y cir cu it, t h e temper at u re r ise of ea ch sect ion sh ou ld be m easu red. Th e t em per a tu re
r ise m en tion ed above m ust n ot exceed t h e specified lim its given in Ta ble 6 a n d Ta ble 7.
Ta ble 5. Utilizat ion cat egories (IE C 60947-4-1)
Non -in duct ive or sligh tly indu ct ive loads, r esist a nce fu r naces.
Slip-r in g m ot or s: Sta r t in g, plu ggin g
Squ irr el-ca ge mot or s: St ar t in g, swit ch in g off mot or s dur ing r u n n in g.
Squ irr el-ca ge mot or s: St ar t in g, plu ggin g
(E xpla n at ion)
(1) Wh en BS a is clos ed, cu r r en t flows a s (＋) → BS S → BS a
→ 52b → (CC) → (－)
pick ed up.
(2) When pick ed up, t h e ch a n geover 52b con t act opens, cur r en t flows
a s (＋)→ BSS → 52a → (H C) → (CC) → (－) a nd is excit ed at
bot h coils H C a nd CC. Aft er pick -u p, t h e in t er n al r esist a n ce of
(H C) is la r ge in compa r ison t o t h at of (CC) so cur r ent decr eases
a n d hea t loss of t h e coil is r edu ced.
Rem a rks : CC : Closin g coil
H C : H oldin g coil
Typica l a pplica t ion s
1)
.
1) 2)
, in chin g
10
a n d is excit ed on ly a t (CC) coil a n d
.