Well the current is a bit low, but he could be trying to build a 20 ft low velocity rail gun or EMP generator... Is this another electronic warfare solution? ;-) -Adam Welch, Ken wrote: >other things to consider -- copper has a positive temp coefficient, which >means the power dissipation will increase until equilibrium or failure > >also, the magnetic field set up in the wire at these current levels can >actually pull the wires together... > > > >-----Original Message----- >From: Bob Ammerman [mailto:rammerman@ADELPHIA.NET] >Sent: Wednesday, May 29, 2002 10:10 AM >To: PICLIST@MITVMA.MIT.EDU >Subject: Re: [EE]:formula/link for current capacity of wire (AC) > > >----- Original Message ----- >From: "Thomas C. Sefranek" >To: >Sent: Wednesday, May 29, 2002 2:21 PM >Subject: Re: [EE]:formula/link for current capacity of wire (AC) > > > > >>On 29 May 2002 at 11:45, Micro Eng wrote: >> >> >> >>>ok..power guys... >>> >>>Whats the formula, given that I have the current and voltage, to >>> >>> >calculate > > >>>the wire size that is required. >>> >>>I'm talking large amounts of current...like 833Amps @120VAC >>> >>> >>.05093 / 1,000 * 833 * 40 = 1.7 volts loss for 4/0, just over 1%. >> >>Wire size is not determined by voltage. >>How much POWER are you willing to loose in the wire? >>How much VOLTAGE loss can you stand? >> >> >>>I know for 200A, I need a 4/0 wire. >>> >>> >>Perhaps: >> >>4/0 wire is .05093 ohms per 1,000 feet. >>For 40 feet, (20' there and back) you get .002 ohms >>@ 200 amps, the voltage drop is .4, >> >> > >200 A * .4 V = 80W > >Note that 80W of heat are going to be generated. This is about 2W / foot >which shouldn't make the wire too hot... > >Bob Ammerman >RAm Systems > >-- >http://www.piclist.com hint: The PICList is archived three different >ways. See http://www.piclist.com/#archives for details. > >-- >http://www.piclist.com hint: The PICList is archived three different >ways. See http://www.piclist.com/#archives for details. > > > > > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.