P Ower Con S U M Pt Ion ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・16; E N D U R A N Ce T O Over -Cu R R En - Hitachi H20-T Technical Notes

2-3-4 P ower Con sum pt ion
Wh en ca lcu lat in g t he in-boa rd temper at u r e r ise of t h e con t rol boar d, swit chboa rd, et c., t he power con sum pt ion of
t h e equ ipm en ts used m ust be consider ed. Th e power consum pt ion of th e sta r ter a n d con t a ct or is given in Ta ble 12.
F r a m e
H 8C～12
H S8,H S10
H 20,HS20
H 25,HS25
H 35,HS35
H 50,HS50
65C
80C
100C
125C
150C
200C
250C
300C
400C
600C
Rem a rks: 1. The con t act r esist an ce wa s m easu r ed between t h e term in a ls of t he power sou rce a n d
t h e loa d sides a ft er th e 50 t h ousa n d cycle elect rica l endu r an ce t est.
2. The power con sumpt ion of t h e con t a ct or represen ts t h e su m of power consum ption
of t h e cur r ent -flowin g section a n d t he coil, a nd t h e power con sum pt ion of t h e st a r ter
r epresen ts t h e sum of power consum pt ion of t h e cont a ct or a n d t h erm a l over load r ela y.
2-3-5 E ndu r a nce t o Over-cu rr en t
Wh en t h e squ irr el-ca ge m otor is dir ect-on-1in e st ar t ed, a st ar t in g cur r ent of 5 t o 6 times t he r a ted cur r ent flows for 1
t o 2 seconds, a n d in som e of t h e loa d t ypes, su ch a cu rr en t m a y flow for lon ger t ha n 5 t o 6 secon ds. Th e t h erm al
over load r ela y wor ks a t over load a n d th e circu it is broken , du rin g wh ich a n over-cur r ent exceedin g t he r a ted cur ren t
flows. Accor din gly, it is necessa r y t o select t h e st a rt er, fu se, break er, et c. cor respon din g to t he loa d ch a r act er ist ics,
a n d also t o k n ow t he en dur a n ce to over -cu rr en t.
In F ig. 15, t h ey in d ica t e t h e a llowa ble t im es for wh ich t h e con t a ct or ca n be con t in u ou s ly u sed a lt h ou gh t h e
t empera t u re r ise of cont a ct s is mor e t h a n t h e specified va lu e in st a nda rd. Not e t h a t a ft er t h e la r ge cur r ent flows, a t ime
in t er val of m or e t h a n 2 h ou rs shou ld be pr ovided.
(Not e: Th e endu r a nce t o over -cu r ren t does n ot depen d on power sour ce volt a ge.)
Ta ble 12. P ower con sumpt ion
Con t a ct P ower consu mpt ion (W)
r esist a n ce
con t act or
(mΩ)
3.8 ～ 8.1
6
3.6 ～ 5.2
10
2.9 ～ 4.3
13
1 .7 ～ 2.5
14
1 .6 ～ 2.2
23
0.6 ～ 1.2
22
0.6 ～ 1.0
29
0.6 ～ 1.0
40
0.6 ～ 1.0
57
0.3 ～ 0.6
48
0.2 ～ 0.5
57
0.2 ～ 0.5
95
0.2 ～ 0.4
118
0.2 ～ 0.4
202
0.2 ～ 0.4
446
st ar t er
10
14
16
22
30
37
44
55
72
63
61
99
122
206
450
16
Con dition of cur r ent
(Ra t ed oper a t ion a l
cu r r en t )
12
20
26
35
50
65
80
100
125
150
180
240
300
400
600