StranGe voLtaGe

[vramp7]

Im getting strange readings from the secondary of a 480v / 240v transformer.
Everythings normal when the lights are off in the panel the transformer is feeding i get 240 between phases and 120 on both phases too ground & nutrel. But when the lights are on I get 240v from phase A to ground & 120 too nutrel. Phase B gets nothing too ground. This causes the gfci outlet too trip when using my plug in tester, as soon as i plug it in it trips the gfci.
Could this be caused by a bad ground, there is no ground wire anywhere in any disconnect or panel.

 

[dbuckley]

Lack of neutral / ground bond. Its a transformer, so you have a SDS...

Oh yeah, your keyboard is broken, theres something wrong with the caps lock key.

 

[vramp7]

I found the problem, the main nutrel wire in the panel was loose in the lug. I tightend her up and everythings fine. I thought it wasnt a ground problem because the metal pipe feeding the panel is going underground to the disconnect switch.