Hioki 3155-01, Instruction Manual

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Appendix 3 Standards for Leakage Current and Current Measurements
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3.2.2 Safety of Information Technology Equipment (IEC 60950 (1991-10)
+ am4 (1996-07))
Power supply Most unfavorable voltage
Point of measurement Between the accessible conductive part or accessible measurement non-
conductive part and the power line (For class
equipment, use a 10 cm × 20
cm sheet of metallic foil.)
Measurement network Same as "Measurement network, touch-current weighted for perception /
reaction" in Appendix 3.2.1, "Methods of measurement of touch-current and
protective conductor current (IEC/TR 60990 (1990-06))"
Measurement Measure with an insulated transformer.
Measure with a voltmeter.
・ Measured current: true rms
・ Variance: 2% max.
・ Input resistance: 1 M Ω min.
・ Input capacity: 200 nF max.
・ Frequency range: 15 Hz to 1 MHz
Allowable values (1) Class equipment (all types) 0.25 mA
(2) Class equipment
・
Hand-held type 0.75 mA
・
Movable type 3.5 mA
・
Fixed / pluggable type 3.5 mA
・
Fixed / permanently connected or pluggable type B 3.5 mA (for currents of
more than 3.5 mA, 5% input current)
Insulating transformer
Equipment under test
L
N
2 1
Measuring instrument
Equipment protective
earth terminal
Equipment protective
earth terminal
Measuring instrument
Equipment under test
N
Insulating transformer
Test circuit for earth leakage current on single-phase equipment
Test circuit for earth leakage current on three-phase equipment
Selector switch
(1) Earth leakage current measurement