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|  DSH 440
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| Short-circuit of motor capacitors
) G! @- r- n( n( H( h/ N; k p | 19.7
+ |# t$ J! A+ { | 60335-1(ed.3)
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Standard: IEC60335-1:1991, 3rd Ed.$ z9 v6 F4 C) u4 D& @9 ]: d
Sub-clause: 19.70 {% `* L5 i% e. |
Sheet No. DSH-440
4 @ \' H; l- k% l/ q& _. c+ r \5 MSubject: Short-circuit of motor capacitors$ v# c* _4 E- X5 U. X3 T: H/ m, W
Key words: -short circuit -motor capacitor' s- a4 h. O* m( R6 Y& f* z
Decision taken at the 40th CTL meeting 2003.
6 P. U) u* t- y2 @; V) uQuestion:
8 ?, b0 C4 H; R8 y N+ s7 U2 C: FTC 61 requested CTL to clarify the test procedure for short-circuiting capacitors in accordance with Sub6 r$ K0 U, b# c2 i/ f6 a
clause 19.7 of IEC 60335-1.. G# V8 R& h0 @$ r' w
Decision:
. m' j, }9 t& j. Q/ Y% N/ vIf the design of the circuit is such that short-circuiting of one capacitor will result in the short-circuiting
; x2 s+ S; L- m7 R' hof the second capacitor, only one capacitor needs to be short-circuited. This is endorsed by the sub clause
% e( J Z+ M2 C) o0 Q% D. u4.3 that states “If it is evident from the construction of the appliance that a particular test is not
0 q, I+ w t& Z2 S( q3 `applicable, the test is not made”.' J. d1 C( w( g* L: i/ A( V
The followings are examples of the circuits.
* X8 N7 N2 ^3 t7 v4 a; d# Q" sIn the Example A:
7 ]4 [! p0 l4 YShort-circuit of capacitor (Cb) terminals is necessary according to the requirements. For the- Z$ a. }& t6 S+ S
capacitor (Ca), short-circuit of its terminals when motor is running is not necessary because0 i+ h; T9 ~& U3 l
the circuit is opened (the switch is opened).) s1 ~7 a4 x# ^; p1 T% I
Also short circuit of its terminals (Ca) when the motor starts is not necessary because it is) l8 `6 e; U! [% S
already covered by the short-circuit of Cb terminals.
! Q/ m; ^. P" hIn the Example B:
! l& T7 E7 n# u( [Only one short-circuit, either Cb1 or Cb2 terminals, is necessary because the testing of one) m( j3 I, N0 k0 u: ^
covers the testing of the other one. Also the short-circuit of Ca terminals is not necessary7 }: R$ c+ ^9 a- d0 h
because of the reason stated in the Example A.
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