INTRODUCTION
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1.2 Product Safety Testing
The importance of testing... User safety
Product Safety Tests are specified during the design and development stages of a product
as well as in the production of the products to insure that it meets basic safety
requirements. These tests are designed to verify the safety of the electrical products in
that they do not jeopardize the safety of the people, domestic animals, and property of
anyone who may come in contact with these products. In an era of soaring liability costs,
original manufacturers of electrical and electronic products must make sure every item is
as safe as possible. All products must be designed and built to prevent electric shock,
even when users abuse the equipment or by-pass built in safety features.
To meet recognized safety standards, one common test is the "dielectric voltage-
withstand test". Safety agencies which require compliance safety testing at both the
initial product design stage and for routine production line testing include: Underwriters
Laboratories, Inc. (UL), the Canadian Standards Association (CSA), the International
Electrotechnical Commission (IEC), the British Standards Institution (BSI), the
Association of German Electrical Engineers (VDE) and (TÜV), the Japanese Standards
Association (JSI). These same agencies may also require that an insulation resistance test
and high current ground bond test be performed.
1.3 Line Leakage Testing
The Line Leakage test is one of many product safety tests which are normally specified
for electrical products by safety testing agencies such as Underwriters Laboratories (UL)
and the International Electrotechnical Committee (IEC). The line leakage specifications
vary as well as the method in which the measurements are taken depending upon the
application or function of a product and the standard to which the product is being tested.
Current Leakage or Line Leakage tests are general terms that actually describe three
different types of tests. These tests are Earth Leakage Current, Enclosure Leakage
Current, and Applied Part Leakage Current. The main differences in these tests are in the
placement of the probe for the measuring device. The Earth Leakage Current is the
leakage current which flows through the ground conductor in the line cord back to earth.
The Enclosure Leakage Current is the current that flows from any enclosure part through
a person back to ground if it were contacted by a person. The Applied Part Leakage
Current or Patient Lead Leakage Current is any leakage that flows from an applied part,
between applied parts or into an applied part. The Applied Part Leakage Current test is
required only for medical equipment. All of these tests are used to determine if products
can be safely operated or handled without posing a shock hazard to the user.
The Model 7611 Line Leakage Tester provides the capability of meeting the line leakage
test specified in the following standards; UL 544, IEC 950, UL 1950, IEC 601-1, UL
2601, UL 1563, UL 3101, IEC 1010 and others. The Line Leakage test is a test which
measures the leakage current of a product through a circuit which is designed to simulate
