Ok. A bit going on here. I bought a craigslist air compressor a few months back. It's an old Speedaire 2hp 40 gallon. The motor draws 19.6 amps at 120 volts. The plug in the garage is only on a 15 amp circuit, and once it gets up to about a hundred pounds the breaker pops. I know that i need a dedicated 20 amp circuit. Here's my dilemma I rent an apartment with a garage, i don't own a home. There is a dedicated 20 amp gfci circuit for the laundry in the basement. It's about a 60 foot run to the compressor. I was hoping to make or buy a 10 gauge extension cord to run the compressor. Otherwise i would have to have a circuit installed. If the extension cord is of the proper gauge, is it any different than running a line to the garage? The laundry is in between the breaker box and the garage, so i wouldn't have extra length. Don't blast me out of the water here. This is why i'm asking
There's lots of science behind it but.... 60' #10 so cord would be more than enough to run your compressor. The rub comes from how far the 20amp gfi is from the panel. That's gonna be #12 wire and the weak link. Is it possible to access the panel and install a 30amp 120 twist lock in a convenient location?
I doubt that even if you use a #8 gauge wire the breaker would last more than one cycle then trip . you need run a circuit just for the compressor. maybe look for a smaller motor and a higher pully ratio.
rookie, how big a breaker would i need if i ran a line to the garage. Why would the 20 pop? This is the 300, no, 320, nope, $350 and counting compressor :-\ Might have been better to buy new. Now i have to install an outlet in someone else's house Its about 25 feet of 12 gauge to the laundry
Pay someone to run a dedicated line ,Where the aircompressor is ,Most general contractors can do it for you .Running off a cord with long length means voltage drop .Thus tripping breaker ,You really need an outlet to the garage ,,,,,
Geuss that's what i'll do. Definately don't like mickey mouse electrics. but just out of curiosity, why would a cord have more of a voltage drop than romex?
If its a good high qaulity cord you shouldnt have any voltage drop issues.Unless its like 100' long. What pressure do you have the compressor shut off at? You can lower your amp draw by lowering the pressure abit. What are you using the compressor for? A 2hp unit doesnt give you much in the cfm department, granted motor hp doesnt mean anything if the pump has been changed. You shouldnt need more than a 110 psi.
A stranded wire can carry current better than a solid wire because of more surface area for the current to travel.
it runs on up to 130psi right now. It's a two cylinder unit. Says industrial duty on the tag. I'll be running impact, hammers, probably a paint gun. Nothing too heavy like a sandblaster. I can wire the motor for 240v as well. I think i'll run a 20 amp 240volt line and have an electrician come make all the connections. I'll drop it down to 110 psi too. Oh, and thanks everyone!
Not totally wrong, but wrong at 60 HZ. This is a myth shoved upon us by audio industry trying to sell expensive speaker wire. Skin effect only impacts at radio frequencies. Cross sectional area per ft determines wire resistance per given material.
Why not remove the outlet in the garage and see if it is wired with #14 or #12 wire. If you get lucky and it is wired with #12 wire, just change the breaker to a 20 amp one and the problem is solved. If it's #14 wire, then you need a work around like every one else has suggested. Good luck.
If 220v is available in your laundry room (dryer outlet?) then run your 10 ga cord from there to the compressor and change the connections at the motor. It'll draw only half the amps as it did on 120v. Voltage drop in the 10 ga cord will not be an issue (the dryer outlet is probaly wired with 10 or 12 ga.). The upper pressure limit could remain where you have it although 130 is way more than you'd ever need. The cut IN pressure is the hiccup-the higher it is, the harder it is for the compressor to start. Of course the higher cut OUT pressure means you have more air stored in the tank which is meaningful if you use regulated air at some much lower pressure.
Funny, but true. Get a dedicated line installed. You could do all of the grunt work with the conduit and wire yourself and leave the loose ends to be tied up by a licensed electrician to make your landlord happy and to cover both of your asses for insurance purposes. I am a landlord and would have kittens if I thought of one of my tenants messing around with the box - and even though I can install a new breaker myself, I would pay to have a licensed electrician do it and have all of the paperwork to prove it too. Maybe the first thing to do is call your land lord - I know I would appreciate the heads up from my own tenant.
This is good knowledge, I had an engineer/electrician telling me that. I install compressors for a living, And I had a customer trying to run a 30hp with solid 10 gauge wire and couldnt figure out why it wouldnt work. His engineer stepped in and told us it should have been stranded no 10 and it would work and this is where I started calling electrical houses and boy was that a fun day...... so yeah I definitly wasent totally clear on how it worked. Oh and he ended up using a no.6 and things worked out! Sorry for goin off topic
If you rewire the motor for 220 volt, the motor will draw about 9.5 amps. upon startup under load that can double or more. I would run a 12/2 romex to a 20 amp 220 volt receptacle, all tied in at the panel to a 2pole 20 amp breaker. As stated earlier, for insurance reasons have it done by an electrician. That is how I did mine and all the others I have done, I am a Licensed Electrician. ELECTRICITY SHOULD BE LEFT TO PROFFESIONALS!
it's 14 gauge wire to the garage, that's the first thing i checked. The motor can be wired for 220, says it on the tag, and has a wiring diagram. I just have to check the pressure switch to make sure it can handle 220. I mentioned it to my landlord a while ago. He was all cool with it. He's the one who sold me my falcon 220 and a 20 amp breaker is the way i'm going to go. Maybe i can do a brake job or two and the compressor will pay for itself.
This is no myth. Look at welding cable. How many strands are in that stuff. There are a ton!! Electrical current actually does follow the surface of wire. Just like in commercial electrical. Stranded wire is rated higher than solid wire.
Do not change the breaker to a 20 amp breaker. The wire is rated for the breaker. I gauantee that the wire on that 15 Amp breaker is 14 gauge. 20 amp breakers run 12 gauge. So if you run a 20 amp breaker on 14 gauge wire, the breaker may not trip and the wire will get real hot. The hotter it gets, the more resistance and the more resistance, the hotter it gets and so on and so on until something gives. Call the fire department!!. You technically should only use 80% of your breaker amperage by code. So a 20 Amp breaker should only use 16 amps. But as you found out on the 15 Amp breaker, it takes more amperage to trip. I would just try a 12 gauge cord that you can make cheap and plug it into the GFCI 20 Amp plug and see how it goes. I bet you'll be fine. The 110 volt compressors were pretty muched designed for 20 amp 110 circuits, nothing more and nothing less. There would be no reason to run 10 gauge as the plug will only be 12 gauge also. The other suggestion that was stated is to get a dryer plug and make a cord out of 10Gauge SO cable. Then when you use your compressor, just plug it into the dryer outlet. The motor won't have to work as hard to run on 220. Also you could use that cord for that future 180 Amp Mig welder also. The reason I suggest 10Gauge for the 220 is that most likely the plug is wired with 10. So utilize it. If your run 12 gauge cord to it , then you limit the future amperage to your new 220 equipment.
All breakers have a hot side and a switched side. When the breaker is off, it kills the wire side. But the bar that the other side clicks onto is always hot, unless the main breaker is switched off, then your panel is dead except the wires coming into the main breaker. If its an apartment, I'd bet you have a 100Amp main. And again, if its an apartment, you are better off just plugging into an existing 110 20Amp outlet or making a cable and wiring it to the dryer plug after rewiring the motor for 220.
if you did this in your rods fuse block you would at the very least melt the circuit that you changed, why would you think this any different? depending on the age of the building there is a slight chance it could have 12g wire, it would be worth the look. the idea of putting the compresor in the laundry room and running longer hose would probably be the easiest and cheapest fix. 12g solid and 12g stranded have the same surface area it would not seem that way though. as far as voltage drop in an extension cord verses romex, there is more resistance in an extention cord creating more voltage drop.
I believe this is an apartment he said he lived in so messing with the breakers would be the last thing I would do. Also there is no way they would run 12 gauge with a 15 Amp breaker. Apartments are built to the cheapest standards. Most lighting and breakers are 15 Amp in apartments. I wouldn't run the compressor in the laundry room as you'd still have to run an air hose out to the shop. The Dryer plug and cord is your best bet as far as bang for the buck. In my House I don't have 1-15 Amp breaker.
Call a licensed electrician to come out and look at what you have and what you want done. Getting electrical advice over the internet is like asking your car to fill out a questionaire about which brand of gasoline it prefers. Some of the information in this thread is right, some of it is wrong, some of it is downright criminal and negligent.
you wont be able to make any changes to the wiring in an apartment complex- they'll have your nuts if they find out- insurance problems, permiting problems and inspections, and all that-- best to put the compressor in the laundry and run a long AIR hose out to your work area. no over amping- no overheating- no rewiring.. just a long air hose
Ah Ha we have a winner? the extra hose you buy will be good for years and the "apartment" portion of it wont get beat up Price out what you need to run a circuit, if you can do it yourself the cost isnt too bad but youll still have $50 or more in it if you dont have any electrcial tools or supplies, higher if you need conduit and a bender
Skin depth in copper @ 60 hz is 8.5mm. The diameter of 10 gauge wire is 5mm. The entire cross sectional area will carry current. What it won't do is flex very well.
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