Re: 3 phase power (was Re: Wireless home LAN - WiFi vs Bluetooth?
On Thu 01 Aug 2019 at 13:06:41 (-0400), rhkramer@gmail.com wrote:
> On Thursday, August 01, 2019 09:41:45 AM David Wright wrote:
> > Like a real locomotive, genuine '2-phase' electrical power has one
> > phase leading the other by 90°, and motors powered by it will be
> > self-starting. (Steam locomotives have double-acting pistons, so they
> > can choose the direction of rotation.)
>
> Have you ever encountered genuiine 2 phase electrical power? (Or any
> multiphase power other than 3 phase?) (Just curious -- I could not instantly
> think of an example.)
No—long before my time. OTOH Direct Current was still being used in a
few areas of the UK when I was at college in the late 1960s, about the
same time as the UK converted from town gas (H&CO) to natural gas.
(Quite an upheaval for those undergoing both.) I went to a field
centre in Gloucestershire in late 1971 where some of the equipment
was still running on DC, and plugged in with these things:
https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#UK_Walsall_Gauge_plug
By this time, I believe that all domestic customers had changed over.
There used to be plenty of 2-phase about, the best known example being
what was the largest installation in its day: Niagara Falls.
Nowadays, I see Philadelphia is one of the last places remaining.
https://www.peco.com/SiteCollectionDocuments/CurrentElecTariff.pdf
shows that their domestic voltages are supplied with both polarities
(5-wire) whereas 2400v is just 3-wire.
Cheers,
David.
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