Re: Unity power factor

2003-02-05 Thread Rich Nute
Hi Neil: > All I get on visiting the site is "404 Page not found error" on their > home page. Access to all other pages seems to be ok. Using their search > engine facility does not seem to find anything with respect to > application notes or harmonics. Anyone else have this probl

Unity power factor

2003-02-03 Thread Neil Helsby
With reference to the Fluke Application Note suggested by Rich and commented on by John. All I get on visiting the site is "404 Page not found error" on their home page. Access to all other pages seems to be ok. Using their search engine facility does not seem to find anything with respect to

Re: Unity Power Factor

2003-01-31 Thread John Woodgate
I read in !emc-pstc that Rich Nute wrote (in <200301311805.kaa24...@epgc264.sdd.hp.com>) about 'Unity Power Factor' on Fri, 31 Jan 2003: > > > >Hi John: > > >> >Yes, delta-wye distribution transformer overheating >> >does occur due to t

Re: Unity Power Factor

2003-01-31 Thread John Woodgate
I read in !emc-pstc that Rich Nute wrote (in <200301311957.laa25...@epgc264.sdd.hp.com>) about 'Unity Power Factor' on Fri, 31 Jan 2003: >Fluke has a good explanation of the deleterious >effects of harmonics. See: > >http://www.fluke.com/ElectricPower/elec.asp

Re: Unity Power Factor

2003-01-31 Thread Rich Nute
Hi John: > Thank you for that and the rest of the information, which could prove to > be very helpful indeed. I would like to use it in my continuing efforts > to defuse the arguments between the former TC74 experts in TC108 and the > SC77A/WG1 people. May I say that the information c

Re: Unity Power Factor

2003-01-31 Thread Rich Nute
Hi John: > >Yes, delta-wye distribution transformer overheating > >does occur due to the circulation and dissipation of > >the triplen harmonics in the primary (delta) winding. > > Thank you for that and the rest of the information, which could prove to > be very helpful indeed

Re: Unity Power Factor

2003-01-31 Thread John Woodgate
I read in !emc-pstc that Rich Nute wrote (in <200301292324.paa09...@epgc264.sdd.hp.com>) about 'Unity Power Factor' on Wed, 29 Jan 2003: >Yes, delta-wye distribution transformer overheating >does occur due to the circulation and dissipation of >the triplen harmon

Re: Unity Power Factor

2003-01-31 Thread John Woodgate
I read in !emc-pstc that Rich Nute wrote (in <200301301638.iaa15...@epgc264.sdd.hp.com>) about 'Unity Power Factor' on Thu, 30 Jan 2003: >As Ken Javor described, in the USA, voltage >distortion is largely a local (privately-owned >wiring) premises problem due to "

Re: Unity Power Factor

2003-01-31 Thread John Woodgate
I read in !emc-pstc that Ken Javor wrote (in <0h9j008afer...@mtaout03.icomcast.net>) about 'Unity Power Factor' on Thu, 30 Jan 2003: >Yes I am in the US so clearly I must have been mistaken. Seriously, when >that business started in 1989 there were relatively few PCs in

Re: Unity Power Factor

2003-01-30 Thread Ken Javor
PC running all day long. It would have been interesting, in retrospect, to have taken line voltage oscillographs at representative locations as the PC density increased. >From: John Woodgate >To: emc-p...@majordomo.ieee.org >Subject: Re: Unity Power Factor >Date: Wed, Jan 29, 200

Re: Unity Power Factor

2003-01-30 Thread Rich Nute
Hi John: > Aren't you in the USA? If so, you must have imagined the peak- > flattening. I am assured by the US experts on SC77A/WG1 that this > phenomenon is unknown in USA, and the only effect of IEC/EN 61000-3-2 is > that it increases the prices of PCs dramatically and keeps US prod

Re: Unity Power Factor

2003-01-30 Thread John Woodgate
I read in !emc-pstc that Ken Javor wrote (in <0h9h00l4ovp...@mtaout02.icomcast.net>) about 'Unity Power Factor' on Wed, 29 Jan 2003: >I noticed this several years ago at >the office building I worked in at the time. My cube moved from one end of >the building to

Re: Unity Power Factor

2003-01-29 Thread Rich Nute
Hi John: > >The only other problem that I know of is distribution > >transformer overheating. But, I believe such > >transformers are very much larger than 3 kVA, so 3 kVA > >of non-linear loads would have very little effect. > > > I mean *concentrations* of loads, individuall

Re: Unity Power Factor

2003-01-29 Thread Ken Javor
in breaker at the two different cubes. This is a power/crest factor issue, not directly a harmonic issue, although drawing current only near the peak of the waveform will definitely generate harmonics. >From: John Woodgate >To: emc-p...@majordomo.ieee.org >Subject: Re: Unity Power Factor

Re: Unity Power Factor

2003-01-29 Thread John Woodgate
I read in !emc-pstc that Rich Nute wrote (in <200301291623.iaa07...@epgc264.sdd.hp.com>) about 'Unity Power Factor' on Wed, 29 Jan 2003: > > > >Hi John: > > >> >In the USA, this has largely been fixed by a change in >> >the USA National

Re: Unity Power Factor

2003-01-29 Thread Rich Nute
Hi John: > >In the USA, this has largely been fixed by a change in > >the USA National Electrical Code. > > There must be quite a number of installations that are not yet upgraded. Where a problem existed, it was fixed by pulling another neutral. > Are there any other problems

Re: Unity Power Factor

2003-01-29 Thread John Woodgate
I read in !emc-pstc that Rich Nute wrote (in <200301281747.jaa29...@epgc264.sdd.hp.com>) about 'Unity Power Factor' on Tue, 28 Jan 2003: > > > > >Hi John: > > >> >No, this is not much of an issue for the U.S. (unless your facilit

Re: Unity Power Factor

2003-01-28 Thread Rich Nute
Hi John: > >No, this is not much of an issue for the U.S. (unless your facility is > >actually affecting the utility); > > ... or frying the neutral conductors with third-harmonic current. In the USA, this has largely been fixed by a change in the USA National Electrical Co

Re: Unity Power Factor

2003-01-28 Thread John Woodgate
I read in !emc-pstc that boconn...@t-yuden.com wrote (in ) about 'Unity Power Factor' on Mon, 27 Jan 2003: >No, this is not much of an issue for the U.S. (unless your facility is >actually affecting the utility); ... or frying the neutral conductors with third-harmonic c

Re: Unity Power Factor

2003-01-28 Thread John Woodgate
I read in !emc-pstc that don_macart...@selinc.com wrote (in ) about 'Unity Power Factor' on Mon, 27 Jan 2003: >Why are so many U.S. manufacturers using Unity Power Factor correctors in >low wattage power supplies? > >Are there any U.S. requirements for Harmonics or they j

RE: Unity Power Factor

2003-01-27 Thread boconn...@t-yuden.com
he surface of earth, so PFC has to be part of the design. Brian -Original Message- From: don_macart...@selinc.com [ mailto:don_macart...@selinc.com] Sent: Monday, January 27, 2003 9:48 AM To: emc-p...@ieee.org Subject: Unity Power Factor Why are so many U.S. manufacturers using Unity

Unity Power Factor

2003-01-27 Thread don_macart...@selinc.com
Why are so many U.S. manufacturers using Unity Power Factor correctors in low wattage power supplies? Are there any U.S. requirements for Harmonics or they just trying to meet CE mark requirements (devices rated > 75W)? Regards, Don This message is from the IEEE EMC Society Product Saf