Paul— About the term “network service,’ in the US, ANSI C84.1 60Hz-voltage ratings states in the footer notes: {Referring to 208Y/120-volt 3ø 4w} “A modification of this three-phase four-wire system is available as a 120/208Y-volt service for single phase, three-wire, open-wye applications.” I suppose it’s somewhat of a slang term by utilty meterguys and line crews, because it’s derived from a (potentially quite large) 4-wire network.

From one US electric utility’s electric rule book: “In locations where PG&E maintains a {4-wire} 120/208 volt secondary system, 3-wire single-phase service normally shall be limited to that which can be supplied by a main switch or service entrance rating of 200 amperes.” From: pge.com/customer_services/business/tariffs/doc/ER2.doc

An example might be a metropolitan area surrounded by multi-story office buildings, with a little old cigar store and its small electric service; i.e., 60 amperes, with only lighting loads so 208 V (versus 240) is not of concern.


[This message has been edited by Bjarney (edited 05-23-2002).]