In reply to Sharp:
> Cheers for the info, out of interest what is the advantage of using a Meggger over a MM, or rather what are the limitations of the reading you get with a MM?
The multimeter applies a low voltage and measures the resultant current when testing resistance, some resistive/insulating materials only work up to a certain voltage then they break down (think about a spark gap, the air is insulating until enough voltage is applied). Mains working voltage is still reasonably low (
40V) but there can be kV+ transients superimposed on it hence testing/specifying insulation at at least 340V, usually more like 2kV.
> ...The other option of course would be to turn it on and lick them, but I'm not sure that's standard electrical testing procedure!
You'd think not but sometimes I wonder!
jk