On Sunday 25 March 2018 21:58:58 John Kasunich wrote: > On Sun, Mar 25, 2018, at 8:29 PM, Gene Heskett wrote: > > > On Sat, Mar 24, 2018, at 5:54 PM, a k wrote: > > > > I measure supply 120 v ac. > > > > Thats another problem, the std line voltage has been 127 volts for > > several decades. I would at least compare what this one reads > > against a known good meter, because either your building wiring is > > wonkie, or that meter belongs in the trashbin, thats about a 5% > > error. > > I beg to differ on that. 127V is NOT the standard and has never been. >"
On Sunday Mar 25 2018 at 10:16 PM (10 hours ago) Gene Heskett Wrote: "It has been since the 70's John. I could probably find it in my copy of the NEC, and its old, 1996 issue. And then again, maybe not. The NEC sets voltage classes, but is far more concerned with the currents. Some time in the mid 1970's it had been 122 volts for a while, before that 117, and in nominally 1950 its was practice at 112 volts. Then circa 1980 it was raised to 127 and still is. That change wound up costing......" NFPA-70 2011 (NEC) Article 100, Definitions, states the following: " Voltage Nominal. A nominal value assigned to a circuit of system for the purpose of conveniently designating its voltage class (e.g. 120/240 volts, 480Y?277 volts, 600 volts).The actual voltage at which a circuit operates can vary from the nominal within a range tat permits satisfactory operation of equipment. Informational Note: See ANSI C84.1-2006 Voltage Ratings for Electric Power Systems and Equipment (60Hz). " Unfortunately I do not have this ANSI standard, but, NFPA-70 220.5(A) Voltages: States: " Unless other voltages are specified, for purposes of calculating branch-circuit and feeder loads, nominal system voltages of 120, 120/240, 208Y/120, 240, 347, 480Y/277. 480, 600Y/347, and 600 volts shall be used." In addition, during my 40+ years of electrical engineering and we have always designed and tested (including for UL approvals) for nominal line voltages of 120V. Typically equipment is designed to operate at 120V +10/-15% The line voltage in my shop fed from a pole transformer supplying only my residence and shop measured 122.5 Volts today at 7:30 am with naarly no load applied. - Milwaukee WI. Respectfully, John Figie > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
