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Testing and measuring tools
Insulating resistance measuring instrument
Auxiliary means
Measuring lines, test prods
Required basic knowledge
Criteria of the protective conductor system, handling of measuring and testing tools, knowledge of measuring and testing processes, how to act after accidents caused by electric current
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Sequence of operations |
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1. Visual inspection |
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- Plant has an own transformer |
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- Neutral point of transformer is earthed by a fusible cut-out |
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- All metallic pans that do not belong to the service circuit are connected with each other by a protective conductor |
The protective conductor must not be connected with the neutral conductor! |
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2. Measuring |
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- The insulation resistance is greater than 25 ohms/volt |
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3. Functional testing |
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- The insulation resistance is to be reduced to a value less than 25 ohms per volt |
Supervisory facility must switch off! |
Testing of the protective measure of
"protective conductor
system"
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