John E. wrote:
I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

What will not be helpful are replies about the character or intelligence of
either of the players or their actions.

Thanks.



The failure that you had was probably caused by your rigger not using an
airride trailer to move the equipment and something got shaken up. Four
weeks of running proves the voltage was not the problem. Some
disgruntled employee probably ****ed in the cabinet.


245 volts is within the normal specs from the utility. AS far as
changing the tap, you should have called in a machine tech to set it up.
An electrician wires only to the safety disconnect switch in the
machine, after that it is your responsibility to call in a machine setup
tech.


John