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Standard(s): No. Year# [( Y: n+ k V8 W+ G, G, T: C- b: K1 b
IEC60065/20012 G# z% t; ^# ~" I5 T6 B9 V
IEC61010-1/2001) x+ h1 j/ x0 m, K+ l
2009 DSH 0753 TRON, MEASCategory: 6 t4 E) E, D( I( X9.1.6Subclause(s): 9 A2 h% _* {9 V) b
6.10.3 5 t* T2 W* r, g5 J# k8 K( q% ODeveloped by:5 t( o( _( `6 _* E5 K
WG4, ETF2, ETF3 & B; N$ l7 c: O- P v* u, Y! l' G6 cSubject:7 {( R) f6 N. o6 h( ] P+ b0 I
Capacitor discharge ( Z: q' P: q" [+ q( T" fvoltage measurement; J; [ e; j8 }; T% J1 {
Key words: 8 O9 n: W6 \/ A2 c- X6 S- Plug discharge ! N6 T3 d( d+ ~5 C; U- Capacitor discharge ; e1 U9 _9 p B1 k7 ?- Shock hazard, o4 v; I8 O6 @2 E
Approved at the 47th CTL ! M6 W% o9 Y) F' O+ Y3 k9 fPlenary Meeting, year 2010$ J* E. F; o8 M6 K
Question:, S5 k: z% I- {( B% b+ @ K
The standards referenced include a test commonly referred to as a plug discharge or capacitor" t, `6 A9 {* S2 t, h- A
discharge test that involves disconnecting the product under test from the mains and+ V; e4 g' Q/ B5 q1 m- T. [! N
measuring the residual voltage across a capacitor(s) at a specified time. The intent in each of * z1 t/ \: R1 x }' L8 ?the referenced standards is the same – measure the maximum voltage obtainable at the time 3 M/ U' p4 u4 P" M8 Qspecified. # z9 A V7 W/ S U% @5 h(1) Each standard has a slightly different description of how the mains disconnect is made, but) r3 |& z0 @; i& D
the intent is to disconnect at the highest voltage possible in the AC power cycle. With the- `8 R. w# v, A& ?% m8 R" P
advent of electronic voltage sensing switches, it is possible to disconnect at the peak voltage in 8 c6 u% Y5 `% \* B0 ^- j" y9 {the AC cycle. Using this procedure seems to be within the intent of the standards and would 0 M0 ^& {- p; E( Lresult in more consistent and repeatable results. Is it acceptable to perform the test this way?- v& {& A% F9 j8 ~
(2) Good laboratory practice dictates that the voltage should be measured with a high input; O8 K; z8 E3 ^: L$ _2 Q0 O
impedance voltmeter. For this test, some standards require the use of a voltmeter with an input8 y. R: Q) ~; d9 i% a) q5 E
resistance of 100 M 1 ± 5 M 1 in parallel with an input capacitance of 25 pF or less. For more " r; k7 w7 C2 E' Tconsistent and repeatable results should this type of meter always be used for this type of test? - A4 k1 Z" ?" r$ r( ]. ODecision:( ~7 s% r* V9 o( r3 {( h3 ?
(1) Yes, this method should always be used for these tests within the CB Scheme. $ M6 l- Y+ H! ~(2) Yes, a meter with the stated input impedance should always be used for these tests within( @5 a d- M; t3 c" u- O$ n3 t8 `4 z( X
the CB Scheme./ B7 Q. o$ x9 i. Q# K
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