Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!kitty!larry From: larry@kitty.UUCP Newsgroups: sci.electronics Subject: Re: 3 phase residential power Message-ID: <2269@kitty.UUCP> Date: Wed, 25-Nov-87 23:44:20 EST Article-I.D.: kitty.2269 Posted: Wed Nov 25 23:44:20 1987 Date-Received: Sun, 29-Nov-87 06:46:32 EST References: <372@intvax.UUCP> Organization: Recognition Research Corp., Clarence, NY Lines: 25 Summary: Not common for residential use... In article <372@intvax.UUCP>, davidson@intvax.UUCP (William M. Davidson) writes: > Does anyone know why 3 phase power in not put into homes? It is MUCH more expensive for a utility to provide, since it requires: (1) three primary (high voltage) wires for all serving areas; and (2) three transformers per residence or close group of residences. Look at residential power lines sometime, and in many cases you will find only ONE primary phase serving a given street or subdivision. > The building I work in is like a small house and it has 3 phase power with > all single phase equipment hooked up in a delta configuration. Ugh! It sounds like you have the scourge of three-phase power, affectionately called "dog leg service" by electricians. This is an el-cheapo three-phase service which is provided by only TWO transformers (one with a center-tapped winding with the CT connected to ground). One of the phases is "open", and the entire 3-phase aspect of the service is subject to instability. This service is common for large farms, but is fortunately disappearing for commercial service. Dog leg service is generally limited to 200 amperes because of the above instability problems. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"