On Jul 5, 2:11*pm, wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, 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.

First of all, 245 VAC is a common AC voltage in the US. *Yes, I know
we say 110 / 220, but it is more like 120 / 240. *

Second, what was the 'handyman' hired to do? *If he wired a number of
1 and 3 phace 110 / 220 volt *outlets, he has no liability. *If he
hard-wired (ran conduit directly to) the equipment, it is open to
discussion. *If he adjusted wiring taps, etc than he MAY be
responsible.

Just to muddy it up even further, we recently put a medical device
through CE approval and were advised by the examiner that our label
should read "110/240", and that's the label we passed with.


However, every controller I have ever seen uses a regulated power
supply. *Decades ago my employer built them. *We tested the supplies
at full load while varying input voltage from 20% below nominal to 20%
above nominal voltage (90 - 130 VAC). *If the equipment operated for 4
weeks, I would say the 'handyman' is not responsible.

Fully agreed.


PlainBill