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 ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
