On Mon, 31 Aug 2015 12:40:31 +0100, wrote:

On Saturday, 29 August 2015 19:27:37 UTC+1, Tough Guy no. 1265 wrote:

I remember at work when our lab was rewired, every bench was fed from a
different phase and there were warnings not to connect equipment on one
bench (eg by RS-232, Ethernet, USB or other low-voltage data cable) to
equipment on another bench, which caused us horrendous problems.

That's a weird idea, you'd think they'd at least have each room on its own phase.

Although I can't see the problem. USB for example would have its ground the same as the appliances earth, which remains constant for all the phases.


Yes, I have never understood why people get so worked up about appliances
connected to multiple phases in close proximity or even connected to each
other. I can't think of a plausible single failure which would be made
more dangerous by two adjacent or connected appliances being on different
phases.

Nobody seems to worry about using uninterruptible power supplies, even
though (depending on the type) they may be delivering an output which
has a random phase relationship to the mains and which therefore could
have a hgher phase to phase voltage than a 3-phase supply.

John

relationship to the incoming

I have an American Power Conversion UPS. It gives out -110 0 +110V, where 0 is the earth, -110 is the neutral, and +110 is the live. I've always assumed it's because it's American, a British one would tie the neutral to the earth. The computer, monitors, printers, stereo, lighting, etc connected to it doesn't seem to care, but I would have thought some devices might expect neutral to be about 0.

--
I used to not get along with my mother-in-law, but over the last few
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