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| DSH 440$ _' s9 \+ p4 s( l. B$ Q: P) ]
: N9 E+ d O/ [ | Short-circuit of motor capacitors
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| 60335-1(ed.3)
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0 ~% G7 G8 n2 x/ c+ |Standard: IEC60335-1:1991, 3rd Ed. n) D0 F8 P& p: e& {2 W+ Z" O
Sub-clause: 19.76 @- x- \" p. a6 x. u
Sheet No. DSH-4406 S% B3 z# t2 r
Subject: Short-circuit of motor capacitors9 K( C/ C% R l+ I- @
Key words: -short circuit -motor capacitor
$ v& I. }) m% R+ gDecision taken at the 40th CTL meeting 2003.
F7 F, C7 s- G5 X' V0 g+ DQuestion:
0 k) x+ O' K) W* I* K" ?* bTC 61 requested CTL to clarify the test procedure for short-circuiting capacitors in accordance with Sub4 z0 G, L( |6 S; w
clause 19.7 of IEC 60335-1.) u- H! n3 h* O4 P/ b* P. J) G
Decision:
( a; @0 P% b+ A8 rIf the design of the circuit is such that short-circuiting of one capacitor will result in the short-circuiting, ]9 q e* V* }4 T8 U
of the second capacitor, only one capacitor needs to be short-circuited. This is endorsed by the sub clause
. I; P$ ~2 ^8 P4.3 that states “If it is evident from the construction of the appliance that a particular test is not
% e6 E9 J8 m0 Y% W0 Oapplicable, the test is not made”.
; q2 X% D, c0 t) B$ DThe followings are examples of the circuits.
$ _4 I/ g: S0 j5 o& ]2 U: GIn the Example A:' x' e$ L( o4 |: W% [
Short-circuit of capacitor (Cb) terminals is necessary according to the requirements. For the9 m4 { |# }& M
capacitor (Ca), short-circuit of its terminals when motor is running is not necessary because7 Q( j* }1 ~3 F7 B0 j
the circuit is opened (the switch is opened).$ y# x- V% o! r" J) a- x
Also short circuit of its terminals (Ca) when the motor starts is not necessary because it is& l" t6 q- E+ _6 a1 f9 D5 S
already covered by the short-circuit of Cb terminals.8 U+ j. `9 z) T. y. o/ x P: Z7 w/ `
In the Example B:
( a7 K# ^! h1 j5 h/ ^2 KOnly one short-circuit, either Cb1 or Cb2 terminals, is necessary because the testing of one
4 L$ W! R0 [- y4 bcovers the testing of the other one. Also the short-circuit of Ca terminals is not necessary7 r5 H |$ P) o7 f- \* }
because of the reason stated in the Example A.
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