Dennis!
I had the weirdest thing happen on a 3/phase/208

This was a simple theatre in which I built partitions in Montreal. I re-ran
a ton of BX circuits that had been previously hidden by a drop ceiling
(they looked very crappy)

One night I get a bunch of text messages from the theatre director. They'd
heard a loud BOOM, and then lights started going out (during a show!!!)
Some lights were flashing on-and-off. Certain wall switches were
functioning, but had begun controlling the wrong lights!!! Imagine my
horrible feelings. I've done a lot of electrical work, but I'm not schooled.

Reading voltages in the load center-  getting 52 volts to ground. Weird.

Turned out, the HVAC unit up on the roof had blown a fuse (from lack of
maintenance) and that caused a 600V/40 amp fuse to blow at the building's
service entrance. The safety switch fuses were all good on my floor, so I
was going nuts, trying to figure what terrible thing I had done. All this
time the theatre directors were wishing they'd never hired me, and I was
wishing I'd never picked up a pair of pliers.

So, a three phase/600V service, when it loses one leg, the neighboring leg
splits itself to it. Hence 52 Volts to ground at the panel. When I began
working on the place, i ignored the heavy transformer bolted to the floor
in front of the circuit panel. I'll never ignore one of those again. In
Quebec, all the newer commercial construction gets a 600V service, and the
building owner supplies the step-down transformer. The wires going into the
transformer are small 3 X # 6awg) , the wires coming out are 4/0)

live and learn. My reputation was restored with those guys. But I advise
everyone to stay away from stuff they don't know now.

On Sat, Jan 17, 2015 at 1:42 PM, Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> Yep weird things do happen. Commercial installations can be a lot more
> complicated. For beginners most will have three phase power. Three hot legs
> and then the grounded conductors. For 208 services you get 208 between any
> two legs and 120 between one hot and the neutral. For smaller 3 phase
> services it is common for the service to of a type known as a "high leg".
> With this set up one of the legs will be 220 volt to the neutral. So as
> branch circuits get connected if the wrong slot is picked for the single
> pole breaker you will have 220 volts. For a home service it is possible for
> the neutral to be open effectively putting some circuits in series and
> under certain conditions you could get excessively high voltage to one side.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Edward Maglott
> Sent: Saturday, January 17, 2015 12:41 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Can 240 volts damage the fridge?
>
> weird things can happen.  Especially if it's an old premises  and has
> undergone multiple modifications over the years by various "electricians."
> The technician coming along now may do something correctly but combined
> with an issue elsewhere in the circuit cause something bad to happen?
> Maybe?  I got called to an office at work because the computers had shut
> down.  There was an electric stapler making a funny sound and it was hot.
> I unplugged it and checked the regular 110 outlet and yep it was getting
> 220.  Numerous devices were destroyed.  Also once in an old house I fount
> myself getting a shock when I had one hand on the power supply of a
> computer an the other hand touched a heat register.  I traced that problem
> with great difficulty to an old outlet on the circuit where the ceramic
> stuff had broken down and caused a connection that wasn't supposed to
> happen.  Can't remember exactly what it was but I guess it must have been
> hot to ground?
>
> On Sat, Jan 17, 2015 at 12:18 PM, Roy Nicholl <RNicholl@nbnet.nb.ca>
> wrote:
>
> > Dave,
> >
> > Electrical breakers are driven by current, not voltage.   An over
> voltage,
> > by itself, will not trip the breaker.   In the example given below it is
> > most probable something downstream would have shorted-out first,
> > causing the draw to spike and trip the breaker.
> >
> >
> >
> > On 17-Jan-2015, at 12:45, Dave Mcneely wrote:
> >
> > > This is a bit confusing.  The power cord to plug the shore power to
> > > an
> > outlet will only fit 110 V A.C. outlets.  It could not be plugged to a
> > 220-240 V outlet unless there was a 110-120 V type outlet wired to the
> > 240 V wiring.  In that case, I would expect the breaker in the van to
> > trip as the internal van wiring heated up.  I would check the breaker,
> > reset it if it is tripped, and then try the refrigerator on 110-120 V
> > circuit.  mcneely
> > >
> > > ---- OlRivrRat <OlRivrRat@COMCAST.NET> wrote:
> > >>        Wouldn't your ShorePower have been plugged into a 110 Outlet
> > >> ~
> > >>
> > >>
> > >> On 16 Jan , 2015, at 4:26 PM, thewestyman wrote:
> > >>
> > >>> The reason why I ask this is because while I was away, the guys
> > >>> wired
> > my workshop to 240 and a lot of items got fried.  But I’m not sure
> > about the van’s fridge because they use the same ones in Europe with 240
> volts.
> > Only my fridge don’t seem to want to restart on 120.
> > >>> Anyone knows anything about this?
> > >>> Zoltan
> > >
> > > --
> > > David McNeely
> >
>