Posted by Jim Wilkins on May 17, 2009, 2:58 pm
On May 17, 10:07am, nob...@xmission.com (Scott) wrote:
The standard US clothes dryer outlet is 240V 30A, or 7200W. My arc
welders are on readily available 50A outlets which supply 12KW, more
than the rating of the usual utility pole transformer. Ours may be
larger because the houses were built with 200A service for electric
heat. The lights don't dim when neighbors weld.
Posted by Eeyore on May 17, 2009, 8:09 pm
to recharge it !
Apparently you can't even use engineering terms properly ( like VA ).
3 phase is ALWAYS used for high power because each phase carries as much as or
current than single phase systems.
If you don't understand the basics, expect to be given a good slapping.
For example in Europe a common standard is 3 phase 400V, probably rated at 60A
or 100A. That'll
supply 72 / 120 kW.
Posted by Scott on May 18, 2009, 1:36 am
On Sun, 17 May 2009 21:09:38 +0100, in alt.energy.homepower, Eeyore
You know that VA is equal to watts with PF=1, don't you? And you
sidestepped the question. I'll rephrase: Explain how a 3-phase supply at N
watts provides more power than a 1-phase supply at N watts.
Your claim was that 3-phase power would be required to support an EV with a
250 mile range, and you made that claim with no qualifications. I am
challenging you to defend your argument, which I deem ludicrous.
Do you claim that no 3-phase system can carry *less* power than a
single-phase system? Yes? No? Your statements are unclear at best,
misleading at worst. Or are you talking about typically available
residential and industrial power services? Because you sounded like you
were talking about pure theory and not making much sense.
I'm starting to question *your* knowledge, you're really not making yourself
look very sharp here.
Posted by clare on May 18, 2009, 2:22 am
On Mon, 18 May 2009 01:36:55 GMT, firstname.lastname@example.org (Scott) wrote:
GENERALLY in north america 3 phase is used for high power
applications. Vast majority of machine tools and industrial processes
run on 3 phase. Virtually all multi-vehicle fork-lift chargers (and a
very large proportion of single unit chargers) are 3 phase.
3 phase is virtually always at higher than single phase voltage and it
is also very uncommon to have much over 350 amp services on single
phase. Even multi-unit residential buildings are usually fed 3 phase,
with 208 single phase, center tapped to provide the standard "110"
Largely a "load ballancing" thing, since the major grid IS 3 phase.
Posted by Eeyore on May 18, 2009, 4:29 pm
That's interesting to know, since the 'official' US single phase voltage is 120V
but I've seen it
marked on equipment as 117, 115 and 110 V.
In Europe, Britain was always 240V single phase / 415V 3 phase for most cabling
under the street (
we don't have many poles here except in the countryside ) and the Continent
220V. Then the EU
'harmonised' us by calling it 230V / 400V by a bit of paperwork fiddling with
Some new installations are actually genuinely 230V now but it'll be decades
before every substation
Nevertheless I regularly get 250V here. I've seen 253 in fact. That makes a
cheap Chinese 'wall
wart' with a traditional transformer buzz a bit.