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 ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
