|
| DSH 440
}! Q- x. R# M; Z4 @ f, E6 W7 @0 z' m. L& {6 f( Y
| Short-circuit of motor capacitors5 x7 J) A! u* j
| 19.7; \( L& L6 [- c% ~$ _' M }
| 60335-1(ed.3)! F1 Y2 d- O( {: A( Q, A
| _& @; `- h- d- T
Standard: IEC60335-1:1991, 3rd Ed.- H7 W3 k3 n" P
Sub-clause: 19.7) ^! f- s! z8 Z1 T* f! i) l% t2 O
Sheet No. DSH-440
5 L) |/ f" ~- Y3 j5 @Subject: Short-circuit of motor capacitors
( h' b" ]! u5 o, o8 z( R* J$ LKey words: -short circuit -motor capacitor
1 F; B" Z! I4 @" eDecision taken at the 40th CTL meeting 2003.
" o% j" A6 D) Y; C& _ _. b LQuestion:; f3 {5 m0 S' ~# i( j
TC 61 requested CTL to clarify the test procedure for short-circuiting capacitors in accordance with Sub
9 R; o8 D' X( I7 kclause 19.7 of IEC 60335-1.' s6 L4 L; A- G+ u% a- E5 G
Decision:
( t1 ^) q& `) {/ F+ Q; ]If the design of the circuit is such that short-circuiting of one capacitor will result in the short-circuiting
$ V0 X6 Y3 `- N6 V: H9 P- l& w7 Tof the second capacitor, only one capacitor needs to be short-circuited. This is endorsed by the sub clause7 O" u Z/ j h) r1 M8 c
4.3 that states “If it is evident from the construction of the appliance that a particular test is not
5 f- ]' o9 I+ b, H9 iapplicable, the test is not made”." G3 ^) s1 R% l( V
The followings are examples of the circuits.
- }% @1 ~: P( {- T! a/ U% dIn the Example A:9 T. b" m) A3 S# k2 D
Short-circuit of capacitor (Cb) terminals is necessary according to the requirements. For the
8 A' ]( a$ s! n# G4 _capacitor (Ca), short-circuit of its terminals when motor is running is not necessary because- h$ V' [) {* P9 D/ D
the circuit is opened (the switch is opened).7 a8 |+ \, ]. c
Also short circuit of its terminals (Ca) when the motor starts is not necessary because it is. z( r7 v/ e% I* _1 T+ P6 a. u
already covered by the short-circuit of Cb terminals.7 L+ I, ~& p/ z( i
In the Example B:
' Y* f/ C6 [7 X( q! i( i0 dOnly one short-circuit, either Cb1 or Cb2 terminals, is necessary because the testing of one
8 E6 p+ i" u* u! R" h* Mcovers the testing of the other one. Also the short-circuit of Ca terminals is not necessary; Q. e1 W( Y/ w- a' G1 \" R8 i' C
because of the reason stated in the Example A.
+ S, T2 E |7 Q. U! r# c, C& B! i( ]' j6 D5 c2 n$ `* D. q* ]
& V7 I& b2 [6 f; i- I* Z
# P+ T2 M! Q! x; S' D, w) Q, n+ L- t/ `+ w+ Q i: W0 y
|
本帖子中包含更多资源
您需要 登录 才可以下载或查看,没有帐号?注册安规
x
|