[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Requiem for a Piglet: I am a murderer(primary-secondary?)



Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

A fascinating question... I'll have to ask next time I talk to a real power
engineer..   I got the primary/secondary distinction finally made when I was
looking into an annoying light blink when a/c compressors start up (in my
neighbor's house as well as mine).  The local SCE engineer (who, by the way,
was totally amazed that anyone would actually be interested in this sort of
thing) kept referring to it as a primary problem, not a secondary rating
problem (8 houses, each with a 200A 240V single phase service, fed from a 50
kVA  pad mount transformer... Hmmm.. kick on all those a/c units at once
(like last week when it was 100+ F) at 20-30A each.. 20A-at-240V = 4.8kW.. * 8
is around 40 kW.. doesn't leave much margin for lights, refrigerators, the
fan in the A/C unit, etc.)... And, if you all start the compressors at
once...)

Typical powerplant generators put out 20-30 kV (for insulation reasons,
mostly).. which is then stepped up to HV (100kV+) for "transmission" then
stepped back down down to MV (67, 34, 14.4, etc.) for "distribution", and
then stepped down again for consumer use (2400, 480, 240, etc.)


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, September 09, 2002 5:07 PM
Subject: Re: Requiem for a Piglet: I am a murderer(primary-secondary?)


> Original poster: "David Huffman by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <huffman-at-fnal.gov>
>
> I'm not a power engineer, but what do they do at the power plant end where
> the voltage is raised for transmittion on the grid? Is the transformer
built
> different? I tend to think of the primary as where the power goes in and
the
> secondary as the output.
> Dave Huffman
> My 2cent
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Monday, September 09, 2002 12:58 PM
> Subject: Re: Requiem for a Piglet: I am a murderer
>
>
> > Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <jimlux-at-earthlink-dot-net>
> >
> > In power engineering terms, the HV winding IS the primary... the LV side
> IS
> > the secondary...
> >
> > ----- Original Message -----
> > From: "Tesla list" <tesla-at-pupman-dot-com>
> > To: <tesla-at-pupman-dot-com>
> > Sent: Saturday, September 07, 2002 10:46 PM
> > Subject: Re: Requiem for a Piglet: I am a murderer
> >
> >
> > > Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> > >
> > > Hi Ken,
> > >
> > > Me thinks that you meant "325 Ohms across the "secondary"" and "0.061
> Ohms
> > > across the "primary"...  Of course, "coilers" tend to reverse the
> meaning
> > > of primary and secondary from what the true pig users mean...   I
guess
> we
> > > all understand the meanings here...
> > >
> > > We must keep are heads during this tragedy...
> > >
> > > Cheers,
> > >
> > > Terry
> > >
> > >
> > > At 12:28 AM 9/8/2002 -0500, you wrote:
> > > >my polemount transformer measures 325 Ohms across the primary,
> secondary
> > is
> > > >0.061 Ohms across the 240 volt winding. It's a 10kVA 14.4kv unit and
> has
> > the
> > > >standard aluminum coils.
> > > >
> > > >KEN
> > > >
> msnip.....
>
>