Hitachi H100C, Technical Notes

Page: 49 / 55

45
Ta ble 33. Wear of cont a ct s
Simple wea r P eelin g wea r Tr a n sit in g wea r Cr a ck wear Mode
Con dit ions of
con t act s
r eplacem en t Gen er a l wea r .
Wh en t h e cont a ct over
t r a vel, t h ick ness of
m ovin g cont a ct or
t h ick n ess of fixed
con t act becom e less
t h a n t h e a llowable
va lu es given in Ta ble
34, r epla ce th e cont a ct s. Th is wea r t ak es place in
a pplica t ions includin g
in ch in g. When t h e
con t act a r ea becom es
less t h a n 50% of t h e
wh ole ar ea, r epla ce t he
con t acts.
Th is wea r is oft en fou nd
in DC applicat ion.
Wh en t h e a r ea of a
t r a nsit in g pa r t is less
t h a n 30% of t h e en tir e
con t act a r ea , r em ove
t h e t r a nsit ed pr oject ion,
a n d t h e cont a ct ca n be
r e-used. Th is wea r is fou nd in
ca se of la r ge-capa cit y
m odels over 100A
fr am e. When t h e a r ea
of cr ack is m or e t h a n
30% of t h e en t ir e a r ea,
r eplace t h e con t act.
Rem a rk: The con t act over t r a vel is t h e am ou n t of m ovem en t of t h e insu lat ed cr ossbar fr om t h e
begin n in g of cont a ct of t h e m ovin g a n d fixed cont a ct s t o t he com plete en d of t h eir
con t act.
Ta ble 34. Allowa ble m inim um over tr a vel a n d a llowa ble min im um t h ick ness of con t act s
Allowa ble min .
t h ick n ess of
con t act (m m )
F r a m e Allowa ble
m in.
over t r a vel
(mm )
Movin g
con t act
F ixed
con t act
Measu r in g m et hod of over t r a vel
H 8C 0.5 0.6 0.6
H 10C,11,12
H S10 0.5 0.6 0.6
H 20,H S20 1 0.3 0.3
H 25,H S25 1 0.3 0.3
H 35,H S35 1 0.3 0.3
H 50,H S50 1 0.3 0.3
H 65C 1 0.5 0.5
Measu r e t he posit ion of oper at ion al
in dicat or at t h e fron t of con t act or
wit h slide ca lipers.
Measu r e t he posit ion , a, of t h e
oper at iona l in dica t or when con ta ct is
st ar t ed by m a n u a l closin g, a n d t he
posit ion , b , of t he oper a t ion a l in di-
ca t or wh en t he coil is excited, t h en
fin d t he over t r a vel.
Over t r a vel = b - a
H 80C 1 0.5 0.5
H 100C 1 0.5 0.5
H 125C 1 0.5 0.5
H 150C 1 0.5 0.5
H 200C 1 1 1
H 250C 1 1 1
H 300C 1 1 1
H 400C 1 1 1
Aft er t h e power of m a in cir cu it is t u r n ed
off, t h e coil is excit ed a nd cont a ct or is
closed, r em ove t h e cover a n d look a t th e
h ole on spr in g h older.
; Wher e t he opposit e side can be
seen t hr ou gh h ole, t h e am ou nt
of over t ra vel is m or e t ha n t h e
a llowa ble va lu e a nd con ta ct or
ca n be used.
; Wher e t he opposit e side can
n ot be seen t h r ou gh h ole, t he
a m ou nt of over tr a vel is less
t h a n allowa ble va lu e, t hen
r eplace t h e con t act s.
H 600C 2 1.5 1.5
Measu r e t he posit ion of oper at ion al indica t or of a u xiliar y con t a ct
a ssem bly in th e sam e m an n er as (A).