personally ive always done an initial 250v IR to prove no loads on the circuit, once proven retest at 500v.
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personally ive always done an initial 250v IR to prove no loads on the circuit, once proven retest at 500v.
Not being funny Chris, but try it for yourself and see. The idea of using 250V first of all is if something is still plugged in or connected, it will skew your results, but the 250V shouldn't damage the equipment. And the best way to find out for yourself is to, say, leave a light or a radio on and see how it affects your results. Then try other types of equipment. That way you will gain experience - which is what you are trying to do. Far better to gain this experience in your own home and at your leisure than scratching your head in front of a customer. If you can get to the point where you recognise the sort of reading that, say, an outside light or an immersion heater might give, you can then seem competent and knowledgeable in front of the customer, and save yourself some time to boot.
Reply to Insulation Resistance - Neutral - Earth Reading Issue? in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net