220V Electrical Questions

[cheaterslick]

Well I can't afford to have 220 for a compressor installed properly in my garage, what are the standards as far as running a line from the house? Like an extention off the dryer etc? It's about 40 feet, I'm thinking it might be too far. Thoughts?

[yorgatron]

i used to run my stick welder off the dryer socket,so that circuit is probably your best bet.it's not like you gotta run the dryer and the compressor at the same time,right? as long as the wire gauge is thick enough you'll be OK.

[SleestakJones]

I just asked the guy at Home Depot the same question last night & he showed me the way.
-John

[crush1776]

I run mine off of the dryer socket and it's way longer than 50 ft. No probs so far. I got a box of three wire line at Home Depot and the three prong end and ran it under the house through a crawlspace.

[Count Scrapula]

Cheater Slick, what size circuit does your air compressor take. Most of the smaller ones take a 20 amp circuit. Assuming that's so , you'd be screwin up to put it on the dryer circuit. The dryer circuit is probably a 30 amp. This means that if something went wronng your 20 amp air compressor would burn up before the dryer circuit breaker would trip. Possibly causin a fire takin all your toys along with it. http://www.jalopyjournal.com/ubbthreads/images/graemlins/frown.gif Don't take a chance on electrical. Do the job right and forget about it.

[cheaterslick]

How bout running a 20 amp (if that's the compressor rating - haven't bought one yet) breaker at the end of the line? Wouldn't that have the same function?

[FeO2]

It's not going to hurt to run a 20amp appliance off of a 30amp circuit. I made an "Extention Cord" using 2 12/3 cables. The longer the run the thicker the wire should be. I used 2#12s for each leg of a 100' run and had no problems. http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif

[manyolcars]

A 30 amp breaker was just right for My 220 cracker box. If I welded too long at a time it would trip the breaker.(20% duty cycle) No way a 20 amp would have been worth doing. The electrician told me to use a dryer plug and 10 gauge wire suitable for outdoor use. In other words, the 10 gauge wire was a big extension cord with a dryer plug on one end and a dryer receptacle on the other. I ran a dryer receptacle off the breaker box. I coiled it up and took it inside when I wasnt using it. . It worked for many years til I got a real garage, then I re-used the 10 gauge wire from my new breaker box to the new location for the welder.
Another very neat trick the electrician taught me is to plant a power pole next to a house or garage (or anywhere) and mount the meter base and breaker box, call the power company and the city for a permit and you are done--forever! What I am saying is your pole and breaker box will be approved with no hassle and you can wire after the breaker box to your hearts content without ever having to get another permit or inspection. Of course, dont run wiring if you arent knowledgeable. If you are capable and need instruction, Home Depot sells a cheap book called "Wiring Simplified" that has current code info, but only the info you need for home, shop and barn wiring--you dont have to wade thru the entire NEC (National Electric Code) book (its huge and covers EVERYTHING including Nuclear Power Plants, Ok maybe thats a small exaggeration) just to find what little you need.
Another time I ran a 12-2 with ground Romex down the wood fence for 125 feet and used that to power my 220V compressor for 2 years.
Another possibilty is to use Direct Burial wire to your shop.

[geno_86ed]

Cheater Slick,

A 40 foot run isn't a big factor at all. What you need to consider is the running amps for the motor on your compressor. It won't be a big deal if it is 20 amp and your dryer outlet is 30 or larger.

The motor starter should have overloads and heaters that will take care and kick off if you lock the rotor.

Just go and buy some properly sized wire and install a compatable plug end on it. 12 gauge is good to 20 amp, 10 is good to 30 amp, and 8 is good to 40, you shouldn't have to run a #8 wire unless your compressor is huge.

if you have any other questions pm me.

Geno

[dixiedog]

If the dryer socket is 3 prong you can use a 10/3 extension cord and cut the ends wire in a plug (the ground and the neutral will be the same) and the 2 hots will be the white & black wires. For a 4 prong outlet (newer houses) go to Home Depot or Lowes and get the footage in 10/4 wire (2 load wires, 1 neutral, 1 ground) and wire it that way if the compressor is wired similar.

Best way is take the compressors wiring diagram with you when you buy the parts and they will help