mblair1@home.net wrote:
> The power required by a three-phase delta-connected resistive load is
> three times the product of the line current and the phase voltage:
>
> 3 * 20 * (208/sqrt(3)) = 7205 watts
>
> or,
>
> 3 * 20 * 120 = 7200 watts (with a bit of round-off error)
A private response to my original message pointed out a shortcut that
might be easier to remember:
Three phase power equals the line voltage times the line current times
the square root of three:
208 * 20 * sqrt(3) = 7205 watts
That's mathematically equivalent to both versions of my calculation
above, but maybe it's easier for some folks to remember. I haven't
done three-phase stuff since college, so I don't remeber any of the
practical shortcuts, assuming I ever learned any of them in the first
place! :-)
Hmm, this is drifting pretty far off-topic. I guess I ought to give
this thread another dose of MV. I just got an MEP-003A 10 kW diesel
generator, mounted on a modified M103A3 1.5-ton trailer chassis. I
plan to tow it behind my M109A3 2.5-ton shop van for mobile power. I
haven't decided yet whether I'll repair the damaged AC wiring in the
shop van and use it as is (for 120V single-phase 60A service), or gut
it and re-wire the van the right way. If I do the latter, I have more
options, since my generator can make 120V single-phase at 104 amps,
120/240V single-phase at 52 amps, or 120/208V three-phase power at 35
amps. I also need to consider that I might want to run the van from
shore power when it's available, so I probably won't choose the
three-phase option.
Anyway, I'm looking for parts:
* Charging voltage regulator for the generator
* Acoustic suppression kit for the generator
* Hand brake handle for the trailer
* Canvas for the trailer (it's not quite the same as M105 canvas)
-- Mark J. Blair, KE6MYK <mblair1@home.net> PGP 2.6.2 public key available from http://pgp.ai.mit.edu/ Web page: http://www.qsl.net/ke6myk/ DO NOT SEND ANY UNSOLICITED COMMERCIAL EMAIL TO THIS SITE
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