DSH 753 Capacitor discharge voltage measurement
http://decisions.iecee.org/icons/ecblank.gifDSH 753
Capacitor discharge voltage measurement
9.1.6 (IEC60065/2001) 6.10.3 (IEC61010-1/2001)
61010-1(ed.2) & 60065(ed.7)
Standard(s): No. Year
IEC60065/2001
IEC61010-1/2001
2009 DSH 0753 TRON, MEASCategory:
9.1.6Subclause(s):
6.10.3
Developed by:
WG4, ETF2, ETF3
Subject:
Capacitor discharge
voltage measurement
Key words:
- Plug discharge
- Capacitor discharge
- Shock hazard
Approved at the 47th CTL
Plenary Meeting, year 2010
Question:
The standards referenced include a test commonly referred to as a plug discharge or capacitor
discharge test that involves disconnecting the product under test from the mains and
measuring the residual voltage across a capacitor(s) at a specified time. The intent in each of
the referenced standards is the same – measure the maximum voltage obtainable at the time
specified.
(1) Each standard has a slightly different description of how the mains disconnect is made, but
the intent is to disconnect at the highest voltage possible in the AC power cycle. With the
advent of electronic voltage sensing switches, it is possible to disconnect at the peak voltage in
the AC cycle. Using this procedure seems to be within the intent of the standards and would
result in more consistent and repeatable results. Is it acceptable to perform the test this way?
(2) Good laboratory practice dictates that the voltage should be measured with a high input
impedance voltmeter. For this test, some standards require the use of a voltmeter with an input
resistance of 100 M 1 ± 5 M 1 in parallel with an input capacitance of 25 pF or less. For more
consistent and repeatable results should this type of meter always be used for this type of test?
Decision:
(1) Yes, this method should always be used for these tests within the CB Scheme.
(2) Yes, a meter with the stated input impedance should always be used for these tests within
the CB Scheme.
页:
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