Hitachi H100C, Technical Notes

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(3) Oper a t ion
(a ) Oper a t ion of 1E t h erm a l over load r ela y
As s h own in F ig. 24, t h e t h er m a l over loa d r ela y con t a in s a n over -cu r r en t det ect or con s ist in g of bim et a ls, a n d
h ea t er s, a n d a con t a ct a ct u a t ed cor r espon din g t o bim eta ls. Wh er e t h e load cu r ren t of t h e m ot or is m a de t o flow
t o t h e h ea t ers placed n ear t h e bim et als, t h ey bends corr espondin g t o t h e am ou nt of load cu r ren t , wit h t h e r esu lt
t h a t t h e con t a ct ca n be a ct u a t ed. If t h is con t a ct is con n ect ed t o t h e coil excit in g cir cu it of t h e con t a ct or , wh en
t h e ben d in g a m ou n t of bim et a ls becom es m or e t h a n t h e pr edet er m in ed va lu e (w h en over -cu r r en t flows), it is
possible t o st op t he m ot or.
(a ) Oper a t ion dia gr a m (b) Con n ect ion dia gr a m
(c) Oper a t ion sequ en ce
F ig. 24 P rot ect ive oper at ion of t h er m a l over load r ela y
(b) Oper a t ion of 2E t h erm a l over load r ela y
Refer to t h e ca t a logu e pa ge 24.
3-2 P E RFORMAN CE
(1) St a n dar ds for t h erm a l over load r ela y
Th e sta n dar d t ype (1 E ) t h erm a l over load rela y a n d 2E th er ma l overloa d r ela y con form t o t h e J IS, J EM a n d IE C st a nd-
a r ds in ta ble in pa ge 26 of t h e ca t a logu e.
(2) Am bien t tempera t u re ch a r act er ist ics
Refer to t h e ca ta logu e, pa ge 25.
Mot or
Th er m a l
over loa d
r ela y
Con t a ct or
St op
Occu r r en ce of
over loa d
H ea t er :
H ea t in g la r ge
Coil excit a t ion :
st op
Bim et a l:Am ou n t
of ben din g la r ge Con t a ct
OF F
Ma in con t a ct
OF F
Cu r r en t la r ge