220 Ext. cord

[Bunk]

I am going to make a 220V ext cord about 50' long. What size wire and would that be 2 or 3 wire? I plan on running this from the dryer plug in the garage to the driveway. The machine is a FC 40D. Also, what size and length should be used for 110V opperation? Thanks,
Bunk

[KHK]

You will need a 3 wire circuit for sure. I would use 3 wire 10 Ga. Use the same wire for 120 or 240 volt.

[brucer]

for 110v i wouldnt go over 10ft long...

you might check on the 50ft run and the gage rating for the extension cord.. you should be able to find a chart somewhere..

[mountain eagle]

Hmm, well if your using the dryer receptacle we'll figure it's breakered at 30A and wired with #10awg wire, the minimum for a 30A circuit. When using a welder there's calculations I don't feel like digging up, and it's been so long since I've bothered.........

Generally I prefer to upsize the wire gauge when possible. For 50' I wouldn't worry too much tho. #10awg is a minimum and that's just because the breaker is protecting the wire and the welder. My understanding of my 50i is that 30 to 50A breakers for welder protection is acceptable, however you must be sure to have the appropriate wire serving the device for the breaker size. If the wire run is over 200' for branch circuits, and with extension cords I feel 100', the wire size should be upsized. The added resistance of the wire over distance can make a difference.

For my 50i we're using a 50A breaker and #6 wire in a 6/3 SO cord. Fortunately the wire was free so I didn't have to balance the cost/ampacity issue......

[WookieWelding]

also make sure you get cord and not romex 10/3 would be sufficient

[mountain eagle]

Good point WW, while 10/3 romex would have the ampacity and be protected by the 30A breaker....... solid wire doesn't cut it for an extension cord, and neither does romex. Not rated as such, not protected as needed for the NEC yada yada so on so forth. That's not to say that in a pinch I haven't poked bare copper in to a receptacle and pinched bare copper through the holes in a male cord cap....... I would never recommend anyone else do that tho......

[d4ve]

Mountain Eagle,

Why is solid wire unacceptable for an extension cord? Is it a flexibility issue with solid vs stranded or does it go beyond that?

---------- Post added at 10:20 PM ---------- Previous post was at 09:58 PM ----------

Here is a link to the National Electrical Code Chart for wire ampacities:

Wire Chart

If you made your extension cord gauge match the largest breaker it will plugged into you should be safe

[mountain eagle]

Basically yes, solid wire is bad for things that move..... Note that every cord you will ever see is stranded wire............

[d4ve]

Thanks for the info. I was thinking that every cord end i have replaced had stranded wire but I never thought about why that was. Is there any difference in the actual electrical current between solid and stranded?

[mountain eagle]

Nope, the electrons don't care in the least............ solid, stranded, flesh......