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Section 1
An Introduction to leakage current testing with the LCB-1010-B
Some amount of leakage current exists in all modern electrical and electronic equipment that connects to an
AC power source. Leakage current is always unintentional: either due to capacitive coupling from the AC
mains circuit to ground (such as exists in AC motors) or as an unintended side effect of EMI suppression
components (such as capacitors connected from AC mains to the chassis of the equipment). The amount of
leakage current and the measurement methods are governed by various end-product safety standards. These
standards often refer to the international standard IEC 60990 - Methods of Measurement of Touch Current
and Protective Conductor Current and other standards (i.e. IEC 61010) for the design and specification of the
leakage current measurement network.
Compliance West USA offers several different leakage current networks to perform testing to numerous end-
product standards. These networks comply with the requirements of the International Committee of Testing
Laboratories Operational Procedure 113 (IECEE CTL-OP 113 Ed. 1.1). This document outlines
requirements for design, calibration, and frequency response of the leakage measurement instrument.
The Compliance West USA LCB leakage current measurement instruments are leakage current networks
only - they must be used with a suitable voltmeter to perform leakage current measurements. The voltmeter
used can significantly affect the results of the measurement. The voltmeter used must have adequate
frequency response to measure the AC leakage-current voltages, and have an input impedance of 1 Megaohm
or greater.
Safety Precautions
Leakage current testing is inherently dangerous because the Equipment Under Test (EUT) is generally
ungrounded during testing. In some safety standards, an additional single-fault condition is introduced during
leakage current testing, which may expose the test operator to hazardous or even lethal voltages.
Test Personnel
Test operators must be properly trained in the procedures for safety performing leakage current testing. Metal
jewelry should not be work during testing. Operators should not allow others into the testing area, especially
when tests are being conducted. Organization is to be stressed. The operator should keep the test area free
of unused leads and equipment.
Testing Area
The area used for conducting leakage current tests should be as remote as possible from normal production
line activities. Only personnel conducting the test should be allowed in the area, and it should be taped or
roped off to preclude casual entry by other employees. In addition, the area should be marked "WARNING
- HIGH VOLTAGE TESTING" or the equivalent to warn others of the nature of the testing taking place.
The bench being used should be non-conductive, and any exposed metal parts should be tied together and
grounded.
