Phase Neutral Reverse

[Spark123]

It could be, tho I read it when everything is energized he sees the p/n reversal. Also, shocks on metalwork smells of a CPC fault to me.

 

[Doris]

I'm not a qualified spark but..I had this Phase-neutral reversal indication for an on-board socket on my band saw in my workshop. Only after taking the motor apart did I think about using my Martindale tester. The cause was not the motor but a burned through neutral cable at the back of a power switch. Had there also been a leak to the chassis then the chassis would have become live without blowing any fuses (everything would have been a the same potential as the live). In my case the motor simply didn't run. In the case of Sherman I imagine a nail through a cable which simultaneously separated the neutral and shorted live to neutral could explain what he reported (in addition to a bad earth).
I thought this worth posting because, although this is a very old thread, anyone searching "phase neutral reversal" would find this and gain some insight into its possible cause. "Phase-neutral reversal" as an explanation on its own is a bit too cryptic and further explanation is always useful.

 

[ericmark]

It sounds like an IT system, this was common with IT which ever phase has the most leakage shows as being earth.

Clearly should not be IT so some where it seems earth has been lost, so first thing is measure the earth loop impedance and see if within limits. For a TT what ever book says, I feel over 100 ohms you should be doing something to improve it.

Remember if TT test the actual earth electrode with nothing connected, you don't want a false reading through other bonded metal work.

I would expect to find no real earth.

 

[flameport]

Before anyone else replies:
this thread is 10 years old