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| DSH 440/ ?% j/ \( R+ m% {, r' g. Z* m
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| Short-circuit of motor capacitors
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| 60335-1(ed.3)' L G6 O+ f* z- z0 f; V/ |
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4 ~- ^3 ]; M; B! p5 i7 K4 @+ }$ aStandard: IEC60335-1:1991, 3rd Ed.9 \# s& d- o) F( ^- J
Sub-clause: 19.7
# c$ |7 z# d& N& s9 qSheet No. DSH-440
( c$ H' @5 g2 V; j$ o& NSubject: Short-circuit of motor capacitors
# r5 M3 ?. h4 d$ MKey words: -short circuit -motor capacitor
1 R1 R9 H" b' s1 ^ _ @Decision taken at the 40th CTL meeting 2003.+ B8 U7 A9 Z- F( @' s2 z
Question:* M. ^8 i3 V! D! Y
TC 61 requested CTL to clarify the test procedure for short-circuiting capacitors in accordance with Sub& N! W( A* f e4 |( C
clause 19.7 of IEC 60335-1.
1 f) k; I8 M+ bDecision:+ P" K( I! W$ ~9 X% c
If the design of the circuit is such that short-circuiting of one capacitor will result in the short-circuiting
# o- j. B3 I, Q* \+ i1 g9 W) rof the second capacitor, only one capacitor needs to be short-circuited. This is endorsed by the sub clause( g6 F& b* s( K2 k% z) ~
4.3 that states “If it is evident from the construction of the appliance that a particular test is not
3 i$ _3 H6 `5 p7 P6 A; A2 a1 Kapplicable, the test is not made”.3 `. Z; ]7 g* _; ^7 ?& c& N3 r
The followings are examples of the circuits.
5 T- b3 c& [# o L3 NIn the Example A:6 U2 K/ A E+ \3 P5 A+ C
Short-circuit of capacitor (Cb) terminals is necessary according to the requirements. For the
- L, l1 W$ s3 n9 Q7 J- Ncapacitor (Ca), short-circuit of its terminals when motor is running is not necessary because' m" p: j6 A; x. A, m8 r( n
the circuit is opened (the switch is opened)." Y. `9 W7 g) x7 p) r4 i
Also short circuit of its terminals (Ca) when the motor starts is not necessary because it is V) ~7 X! c1 ]1 E
already covered by the short-circuit of Cb terminals.
8 R* e$ Q( C9 i- q! d' jIn the Example B:
( [) X2 E) |7 S, F3 p2 f1 COnly one short-circuit, either Cb1 or Cb2 terminals, is necessary because the testing of one9 K; e& M) v3 H/ g! f
covers the testing of the other one. Also the short-circuit of Ca terminals is not necessary
5 I1 n9 l F8 o: v0 {. s6 Qbecause of the reason stated in the Example A.
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