"Archimedes' Lever"
"Phil Allison"

"John E."

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 a STUPID troll !!!

The PSU in the CNC blew cos it was a pile of **** PLUS the design was
100%
incompetant cos it gave no protection to the delicate and expensive load.

Bet it was old and way past use by date too.

**** off TROLL !!


Probably a good call, since modern switchers, which the DC supplies
for these things usually are, can handle up to about 265 volts. Even a
bit more, typically.


** Unlikely it was a SMPS based on the OP's admittedly poor and incomplete
info.

Cos SMPS do not have multi-taps for AC input voltage - PLUS if an
off-line switcher fails from overvoltage, it just blows the fuse and goes
dead.

But losing regulation and over-voltaging the load ( as was alleged by the
OP) is another scenario altogether - more often associated with old age or
the failure of one of a few critical components in the regulation loop.



...... Phil