groho

well, it was about time. My old craftsman oil-less air compressor is on it's last leg after 18 yrs; 4hp@25gal, ran 9cfm@40psi, and 7cfm@90psi. I'm considering a oil unit cuz it's quieter. I'm limited to a 110V unit. Everything I'm seeing is actually less CFM then what I'm currently running. I'd have to pull in a new power&breaker for 220V, so I'm trying to avoid it. I use air tools every weekend, and considering taking a shot a painting the coupe. What are you guys running?

hotrod351

well i have three compressors, a 5hp gas, a 2hp 220 volt and a dewalt 110 volt. the dewalt is small, the 220 volt is an older twin cylinder pump. you just need to search the internet and you can find a good compressor that will pump out the volume and will run on 110 volts. after all a lot of the compressors electric motors will run on 100 or 220. you just have to change the wiring connections in the motor. at least thats the way the last few electric ones i had were sit up for.

mr_velocity

Power is power, whether electrical or air. There are a lot of claims of a motor being 5hp, I call BS. A 5hp motor at load running at 110V will draw 33amps. Problem with a lot of consumer products is pure BS with HP ratings, Ohm's law calls them out every time. Probably why you're seeing a difference in the cfm numbers.

A 220v motor will use half the current of a 110v unit so you can double the "power" capacity of your circuit by just switching it to 220v. If your circuit is only for the compressor and its the only outlet on that circuit you can change it to 220v just by changing the breaker and outlet. You only need 2wires plus ground for 220v just like you have for your current 110v circuit. If you don't know about wiring consult an electrician.

Power in Watts = Voltage x Amperage
1 hp = 747 watts

My advice, if you're doing this in the garage and you plan to stay there a while then run power once. Just pull a 220V 60amp circuit and put a sub panel in the garage. Then you're ready for the compressor, welder and anything else you might need. The cost difference in just going to be in material.

I've gotten away with the 5hp (BS) craftsman for 20 years, last year I upgraded. Now I think to myself "I'm an idiot, I should have done this years ago." I'd always need to wait for the craftsman to "catch up". Lots of moisture in the air because the craftsman inefficient pump made the air too hot. If you're going to paint, HVLP guns use a lot of air.

I searched craigslist for months then finally the Quincy came up. I picked it up for $650. This is a true 5hp compressor, 17cfm at 175psi rated at 100% duty cycle. Along with my new Miller welder, the best investment I've made in the garage. It's very very very quiet and I never run out of air even using the blast cab. Absolutely the best $650 I've ever spent on a tool.

Find yourself a "commercial" compressor, there are lots of them available on craigslist. Then buy a case of beer for your friends to help you install it. The Quincy weighs in at nearly 800lbs, the pump alone is 295lbs.

groho

MrV, if I'm gonna run a bohemath like that, I'd have to replace my current 12/2wG, with 10/3wG for a proper 220.....thank the peeps that write the code.

mr_velocity

Don't blame the code. If you're going to run an electric motor make sure you run oversize wire. Smaller wire = more resistance = lower voltage to the motor = more current = more heat = fried motor For 220 you only need 10/2, the only time you need a neutral is if you need to make 110V, otherwise its just the 2 hots plus ground.

I was in the boat lift business for a while, long runs out to the docks and electricians used to argue with me when it comes to wire sizes. Well you only need 20 amps so that's 12 gauge wire. 100' run of 12 gauge for 20 amps means fried motors. If I lost the argument I refused to warranty the motor. If I won the argument.....well I never had a motor failure in the 100s I installed.

Also if you're running 100% duty cycle you need to figure 80% of the rating.

I still think the best bet is to pull a 60A circuit and put a sub in the garage. Then find a good used commercial compressor. I put a 100amp sub in my garage 20 years ago, best decision I ever made. I only filled 11 of the 30 breaker slots, 4 last summer for the compressor and welder.

Either way, you could make your 110v into 220v if its only 1 outlet on the circuit. It will open the options a little more on compressor choices.

Where you located?

chris66dad

I have two compressors (110volts and 7cfm @ 50psi) . I will use either 1 or both depending on what I am doing. I used the set up to paint the 66. They are also on DIFFERENT 110 electrical circuits.
I needed to get the 10 CFM of air volume the spray gun needed. The compressor regulators were set to 90psi and they were T'eed into the air dryer with 25 foot hoses which helped cool the air and allow the water to condense.

The air dryer regulator was set to 50 PSI (wall pressure). The gun was set for about 10psi at the nozzle. We never ran out of air pressure even on long shoots.

jcoby

Along with what everyone else has posted, there was a class action suit against the compressor manufacturers about the horsepower ratings a few years back. They were using peak/instantaneous HP instead of continuous.

So that's why you aren't able to find a newer compressor that has the same rating. It just isn't possible to get an honest 4hp out of a 110v system that won't blow almost every breaker it's plugged into.