The Stovebolt Site Forums The Shop Area General Truck Talk 240 Volt Wiring?

I didn't know where to post this. It goes along with the air compressor thread in tools. It regards tools in regards to my truck which in regards makes it "General"!
I was checkin' out the wiring going to my house and my panel. Looks like it's been upgraded to a 3 wire system. I've got 2 wires coming from the meter that connect to the MAIN breaker and 1 that connects to the neutral? bar. The main breaker is 100 amp.
What do I gotta do to add a 240 volt breaker? Do I just install the breaker and then when running the wire, I'll have 2 hot wires at the breaker instead of one? And the 3rd is ground/neutral?
My new thought on this compressor subject is if I have the capability why not just install a dedicated 240 outlet. It'll be temporary until February when the remodel starts and our panel gets upgraded. After the remodel I'll add a subpanel in the garage.
Can I run this temporary 240 volt breaker and outlet?

Licensed experienced sparky to your rescue .You need a 2 pole breaker of the correct amperage.You need 2 phase or hot conductors plus an equipment ground wire.For example, if the motor plate says 18 amps at 230/240 volt, you'll need the following;the wire must be rated to carry 125% of the motor load, that would be number 10 copper in this senario.If the compressor is not with in site of the panel, you'll need a disconnecting means if the compressor doesn't allready have one.The disconnect must be rated 115% of the motor load.Generally,home compressors won't need a motor starter(solinoid switch),should have a built in disconnecting means..The breaker you add to feed the compressor can be sized to 250% more than the motor load.But in this senario,# 10 wire can never be protected by more than a 30 amp breaker.Rather than go through all the code book stuff, tell me the full load amperage listed on the motor data plate, I'll tell ya what to buy. Yes you can run a temporary hookup, just be careful to place the wire where it's free from abuse.

Uh oh--this thread could get scary in a minute--people start sharing their jack legged wiring schemes. Man o Man. Good thing that Mugsy has the licensed Tony but I hope no licensed electricians show up at my place. Prolly have heart attacks. I must say though I never burn up wires or motors--way overwired I imagine--and i pay a lotta atention to breaker sizes.

Got a buddy with a 48 Dodge--he was havin a problem with his welder--asked me over to help. Got there and discovered he had the whole shop wired with orange extension cords #14 wire as far as I could tell-- wired directly into the sub panel--pretty comical.

It's all fun and games until someone get hurt.If you buddy has a fire,let's say it's not caused by electrcial, but some spilled solvent.His insurance carrier, if he has insurance ,may reduce the claim ,saying his sloppy wiring shows negligence on his part contributing to unsafe conditions which lead up to the fire.Otherwords,extension cords are no substitute for fixed building wiring.Something like 90 percent of residential electrial fires are caused by extension cords or faulty appliances, not the house wiring.
But I've seen really bad overloaded wiring in factories that never smoked, I guess it's like the lottery

Tony--

Really kinda a comical story--when my Dodgebolt buddy asked me over-- I told him I couldnt help because his wiring was a mess--couldn't handle the load. He subsequently told me he solved the problem by buying some huge extension cord and running it from an old window unit outlet in the house. He lives in the same little berg as me and later on--his soccer mom neighbors got on him about a dilapidated garage (which of course it was) . City came out and inspected the thing and condemned it. . I'm sure the electical service brought a few chuckles. Dodgebolt told me it cost $8k to save the building including new wiring.

I was down in Bolivia a couple times three and four years ago on a construction site. One of the local indigenous personnel needed an outlet for his power saw, so he grabbed a duplex outlet from the supplies, cut himself off a hunk of 12/2 (no ground) stripped it with his teeth and screwed it together without a box or even any electrical tape. At the breaker box, he didn't even screw the wire into a breaker, he just jammed the wires in there on top of the wires already in a breaker. No strain relief, didn't replace the box cover because his wire was hanging out of it...

I was wondering if he learned the hard way to strip the business end (with his teeth!) BEFORE jamming the other end into the box.

Mugsy,

Before heading to the home improvement store to grab some breakers, write down the breaker box manufacturer's name and take it with you. Some of the systems are proprietary, and one size/style does not fit all boxes.

Charles

Truckedup,
I don't have a plate to look at but, the 240V I'm thinking about exchanging for says "15 Amp Min. Branch Circuit" under specs on the Sears webpage. It lists the same for the 120V compressor I bought and wanna exchange. I checked the plate this morning and it does say 120V/15Amp.
So, what do I gotta do for 240V/15Amp?
Thanks.

Hey BigGreen, What part of Maryland?

David

15 amp minimum circuit capacity means you can run a length of 14-2 wiring and use a 15 amp 2 pole breaker.
Personally,I would use 12-2 on a 20 amp 2 pole breaker.On the panel door or the deadfront(metal breaker cover) the acceptable breaker types will be listed,just buy one of those.The white and black wires go on the breaker, the bare grounding conductor on the terminal strip with the rest of them.Your compressor should have built in motor overload protection and a disconnect on the unit.If you wire it permanently,it's best to use a plug and receptable so the unit can be easily moved if necessary.
Best to shut off the main breaker, practice a few times unplugging and plugging in the new breaker so you get a feel for it.And tighten all screws and or wires nuts firmly,make absolutly sure the grounding is good.

Awesome! I can do that. Thanks Tony.

Next we will teach you how to juggle screwdrivers in front of an open 480 volt panel. A friend's dad did that once in a grain elevator. Two of the three screwdrivers were vaporized. Suprisingly enough, it didn't start a dust explosion.