Thanks Steve for your reply. However, after numerous return trips to this stable, the problem is still not corrected. I am about to pull my hair out.

I NEED HELP. I have depleted all of my thoughts. Has anyone else got any suggestions?

Here's the situation. This is a facility that I done a service upgrade on a couple of years ago. I installed a new meter and 200 amp service disco. Then, there is numerous overhead triplex's that branch off from there. One of which goes to the stable. It feeds a 100 amp panel that I also installed on another occasion. From there the owner has done some of his own unique wiring(real scary).

After the first time of burning this unit up(which the manufacturer says is the timer board), I ran a seperate dedicated circuit to the 100 amp panel, with a ground. The initial circuit he was using was not grounded. This still didn't cure the problem, again another timer board burn't. I can't find anything wrong.It almost has to be something backfeeding on the neutral, but is that possible.

Should this 100 amp panel have isolated ground and neutral bars like a subpanel since it is downstream from the service disco?