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Standard(s): No. Year; j. I2 I3 _! d) l+ C0 q
IEC60065/2001" h% a2 B+ k1 ^' x9 J" i
IEC61010-1/2001 2 `' g2 O; I. G2 `; l$ h X2009 DSH 0753 TRON, MEASCategory: " o @% g" U; {5 u+ `9.1.6Subclause(s): % z: q/ R. s C, |9 g, }
6.10.3 : ^# Q! L% ]3 O8 K* S5 w" p/ q; J7 J3 HDeveloped by:5 W) t6 A7 i9 w/ E* {( t. u
WG4, ETF2, ETF3% l# L* q1 e; }1 f7 x! g a2 V8 t
Subject: 6 W- G( |# e. R' aCapacitor discharge+ k' S; o- D5 z; r" @. M% A
voltage measurement - F4 e) A. g( ]# W" d- W8 R6 wKey words: 6 {! }! ~& J& B# `' d x! c- Plug discharge + A G4 I' J8 I2 e- Capacitor discharge * \1 L1 t: o0 f- Shock hazard % p$ N1 J3 Z. o. {: DApproved at the 47th CTL 8 Q* O/ s+ x/ [5 UPlenary Meeting, year 2010 8 j5 c, ?6 g" ?: lQuestion: 8 ^2 Y) X( _- p8 WThe standards referenced include a test commonly referred to as a plug discharge or capacitor ! d/ c' x2 K; U% u) u% {discharge test that involves disconnecting the product under test from the mains and / Q5 q6 B P7 X6 ^' [3 h y6 @measuring the residual voltage across a capacitor(s) at a specified time. The intent in each of) B% }! |7 S$ W
the referenced standards is the same – measure the maximum voltage obtainable at the time* I Y) Z: q2 I- P
specified.( U% g W- ?9 i$ U8 a; O B6 ^
(1) Each standard has a slightly different description of how the mains disconnect is made, but% u& w4 B( H' ^4 q' [" M
the intent is to disconnect at the highest voltage possible in the AC power cycle. With the 0 M% `3 [, ]; C4 A' B* Eadvent of electronic voltage sensing switches, it is possible to disconnect at the peak voltage in1 }) N1 h k+ i$ L; m3 F5 p
the AC cycle. Using this procedure seems to be within the intent of the standards and would r$ a( ?; y' x5 E' ]result in more consistent and repeatable results. Is it acceptable to perform the test this way? ! l O& A3 q( T' ?% y% u$ R0 ^(2) Good laboratory practice dictates that the voltage should be measured with a high input 8 [3 U# u2 T* m+ c7 Gimpedance voltmeter. For this test, some standards require the use of a voltmeter with an input! `4 r, Z8 f0 \5 y0 k' M
resistance of 100 M 1 ± 5 M 1 in parallel with an input capacitance of 25 pF or less. For more % O# ?6 T, a: dconsistent and repeatable results should this type of meter always be used for this type of test?/ ^0 }' K: `; O
Decision: . I$ F0 l& @9 z0 [* l(1) Yes, this method should always be used for these tests within the CB Scheme.5 f0 m6 R" k8 s
(2) Yes, a meter with the stated input impedance should always be used for these tests within 6 F; m( a* b E8 ythe CB Scheme.( ~! j" N& k+ X n" i6 Y
DSH 7537 E1 T) d& S) a: b