110 from 3 phase

[fhorn]

I am attempting to help a friend. This is a small commercial building. Someone has pulled a 110v circuit from one leg of a 3 phase panel and it has ceased functioning (I am assuming it worked at one time). I have one of those little plug-in-outlet testers for polarity etc and it shows all is well. Another tester that just shows a light for the appropriate voltage lights the 120v light, but when I check voltage with a vom I get approx 141v and nothing plugged into the outlets works. The hot is connected to a breaker on one leg of the three phase and the neutral goes to what would be the neutral bar in the box. The problem is I do not see a neutral coming into the box, just the three large hot wires for the 3 phase and the neutral bar APPEARS (I have not checked continuity yet) to be connected to the ground bar. About all the info I have at this point. Anyone have any thoughts?

 

[Richard Burns]

I am more familiar with the UK power supply, but from your readings you have voltage at the outlet as expected but nothing will run.It would be a good idea to check if it ever worked and if so if anything has changed in the intervening time.Other than that it sounds like you have a loose connection somewhere, where there is just enough contact to supply a voltage but it breaks down when it draws current to power a load.Check the neutral connection (in the UK at the incoming supply the neutral could well be connected to ground, but there are different arrangements in the US) and also check that the breaker is functioning correctly, it may be just starting to break down and not close properly.

 

[Guitarist]

I think that you would get a better response from a US forum, as our systems here in the UK are different to yours.

 

[Knobhead]

You clearly don't know what you're doing. Get a registered electrician to have a look. I will make a site visit for travel expences and accommodation fees.

 

[ian.settle1]

You clearly don't know what you're doing. Get a registered electrician to have a look. I will make a site visit for travel expences and accommodation fees.

Tony your not a licenced electrician in the USA

 

[fhorn]

I asked an honest question. No need for the snarky response. The poor connection idea is good. Good enough connection for a meter but not enough to carry any load. Thanks