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Minimum values of insulation resistance

Wombat
What is the science behind the 1 MOhm minimum insulation resistance? What is the basis for this particular value?
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    original requirement was based on a fraction of the total load the installation was to be loaded with. 



    That sounds like the old Electricity Supply Regulations - they permitted a maximum leakage of one ten thousandth part of the installation's max demand. (e.g. 10mA for a 100A single phase supply). I'm struggling to equate that to 1 MΩ though.


    Earlier regs did have various different ways of calculating the IR limit - often based on the number of points.


       - Andy.
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  • 0

    original requirement was based on a fraction of the total load the installation was to be loaded with. 



    That sounds like the old Electricity Supply Regulations - they permitted a maximum leakage of one ten thousandth part of the installation's max demand. (e.g. 10mA for a 100A single phase supply). I'm struggling to equate that to 1 MΩ though.


    Earlier regs did have various different ways of calculating the IR limit - often based on the number of points.


       - Andy.
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