lead size and length question

admin

Kind of a boring question....Welding lead sizes are always referred to like this:1/02/03/0First question.What the heck do those numbers actually mean?Next question.I am looking to get 100 foot of leads (100 ft for work and 100 ft for stinger) for my new Miller TB 302G.How do I determine the size of cable required so as not experience  voltage drop that will affect my welding?Thanks for the help,Russ
Reply:Generally you do not want a voltage drop of more than 4 volts.  There are tables that will give the resistance in ohms per kilometer or in imperial measure.Your total length is 200 feet of cable.  2/0 has a resistance of 0.077 ohms per 1000 feet or 0.0154 ohms per 200 feet.Volts = amps X ohms   or  300 amps X 0.0154 = 4.62 voltage drop.Now the question is if you are going to use 300 amps all the time or more likely you will top out at 200 ???There are cable tables that will tell you that 2/0 cable would be safe to use at 200 amps and the work 100 feet away from the power source.  It is much easier to surf around and read the recommended cable sizes on a table.
Reply:This has a chart with lead lenght and suggested cable size is about half way down:http://www.generalcable.com/NR/rdonl...Ty_RHH_RHW.pdfAlso every miller welder manual that I have seen has a similar chart. But also takes into account duty cycle
Reply:I use 2/0 on my Bobcat 250 and XMT 304.Wire thickness is measured in gauge.   Gauge is a funny thing,  above zero, the bigger the number, the thinner the wire (12 ga is thinner than 2 ga), but below zero, the bigger the number the thicker the wire (3/0 is thicker than 1/0).Welding lead is mostly in the 2 ga to 3/0 range, though it can be thicker or thinner.  My Passport mig came with a 6 ga work lead and my plasma cutter has a tiny little work cable only about 12 ga it seems.Typical wire sizes, thin to thick-18 ga (thin)14 ga12 ga10 ga8 ga6 ga4 ga2 ga1 ga0/01/02/03/04/0 (thick)MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Thanks for that description. Based on what you say, what MIller told me and what I read in these charts, I am going to go with 2/0 as well.Thanks again for all the info,Russ