On Thursday, March 10, 2011 09:23:17 AM Mark Wendt did opine: > On 03/10/2011 12:51 AM, Jon Elson wrote: > > Peter Blodow wrote: > >> I think it would be worth wile to build up a powerful lobby in the US > >> to enforce decent power supply for everyone - what a shame for the > >> most powerful and most technically oriented country in the world to > >> discuss about how to get motors and machines running! > > > > The infrastructure changes that would be required are beyond belief. > > For instance, there is 3 phase > > 7200 V power half a block away from me, but there is only one phase > > 7200 V main running down > > my street, and it runs for at least half a mile down the major street, > > then branches into the side streets. > > So, all those houses and streets have ONLY single-phase high tension. > > I can think of areas I've been > > where the high tension single phase feed goes for literally many miles > > down rural roads. > > > > In cities, there is often 3-phase high tension feeders near to every > > house, but even still, there is a HUGE > > amount of infrastructure that would have to be changed. > > > > So, poles would need to be replaced or at least have cross-arms added, > > all residential transformers in the country > > would have to be replaced, all service lead-ins would have to be > > changed from 3-wire to 4-wire, all > > residential meters would have to be replaced, all circuit breaker > > panels would have to be replaced. > > Then, you have to figure eventually replacing all major loads such as > > ovens, clothes dryers and > > air conditioners with 3-phase. > > > > My house has its own, personal 50 KVA transformer. We have 200 A 240 > > V service, so that > > is 48 KVA. Can you imaging the industry that would have to develop to > > replace EVERY residential > > transformer in the WHOLE country? > > > > Few homes have any 3-phase loads unless they have serious home shops, > > so really the need for 3-phase > > power is not that big a problem, especially now that VFDs are > > available. > > > > > > Jon > > And the last thing we need in this country is more laws on the books > telling us how we need to spend our money. > > Mark > Particularly when 9 out of 10 of them were passed to preserve some business model that's become obsolete because they want to maintain the status quo instead of innovating to stay competitive.
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