3-phase (was: Re: CDC 9766 Drive and packs)

From: Christian Fandt <cfandt_at_netsync.net>
Date: Thu Feb 4 08:06:32 1999

Upon the date 10:18 AM 2/4/99 +0100, Philip.Belben_at_pgen.com said something
like:

>>
>> 36kW!! Ouch! And cost of electricity is, I understand, higher than in the
>> US, true? Except Jamestown, we pay only $0.03565 per KWH :-) so
>electric
>> heat is not such a financial killer for homeowners (or for nuts like me
>> with working big iron computers in the basement).
>
>Dual tarriff (?sp) is quite common. The most usual scheme is called
>"economy 7" which charges about 14c US per kWh during the day and somewhat
>less (I think it's less than 5c - sorry, I am not in the UK this week so I
>can't check) for a seven-hour period starting at midnight +/- one hour
>(exactly midnight on older installations). Some circuits - mainly heating
>- are controlled by the same timeswitch (older installations) or radio
>receiver (newer ones) as the tarriff selector on the meter.

In this electrical district the residential rate is the $0.03565 24/7. The
Jamestown Board of Public Utilities generates some of the power (coal-fired
steam) while the rest is hydropower bought from the Niagara Power Project
up near the Falls. We pay them, IIRC, around $0.025 per KWH. BPU is a
publicly owned, not-for-profit utility (taxpayers technically own it.) At
summertime peak the BPU distributes approx 80 MW.

OTOH, the two districts outside of BPU average $0.08 or $0.09 per KWH. They
are private, for-profit utilities.

>
>It is said that many night clubs use economy 7 tarriff despite no heating
>load...
>
>Other schemes exist. One called "heatwise" also gives you a couple of
>short periods of cheap power during the day...

Many other electrical districts around the US have dual tariff fees. Seems
to be as many variations as there are separate utility companies :)

>
>
>> Yes, very few private residences in North America have 3 ph power
>_unless_
>> it was asked for and installed, of course at an extra co$t. If someone
>has
>> a garage or machine shop at home (and the local zoning laws permit it)
>then
>> 3 ph can be installed. Otherwise, bigger apartment buildings, larger
>> offices and factory buildings are usually wired for 3 ph at 240 volts or
>> 480 volts.
>
>Gosh. I've seen 3-phase 208 volts in the US, but what would they use 240
>for?

Excuse the brain glitch Phil. I meant 208V 3ph. Normally 240V 1ph, center
grounded, is wired to residential and small office users.

Regards, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt_at_netsync.net
Member of Antique Wireless Association
        URL: http://www.ggw.org/freenet/a/awa/
Received on Thu Feb 04 1999 - 08:06:32 GMT

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