Electrical Gurus, need advice on adding 240v for air compressor

[projectslideway]

Hey Guys,

I don't know much about home electrical and I'm currently in the market for purchasing an air compressor for my garage. I would like to see if it would be possible to add a 240 receptacle in the garage without having to step up from my current 100a breaker box. If I need to upgrade too much I'll likely select a smaller air compressor and just deal with it. Any advice is appreciated... thanks!

 

[2013gt5]

Looks like you will be fine. Is that your main panel or a sub panel?

 

[projectslideway]

Looks like you will be fine. Is that your main panel or a sub panel?

It's the main panel.

 

[Tylerc]

You have two free spots on the bottom that will work. What kind of loads do you have on your house? A.c. stove washer etc? I have a 60 amp sub panel in my shop fed from my 100 main in house and never blow it using my welder.

Usually air compressor are 220 with a 30 amp breaker. Should be fine.

 

[projectslideway]

You have two free spots on the bottom that will work. What kind of loads do you have on your house? A.c. stove washer etc? I have a 60 amp sub panel in my shop fed from my 100 main in house and never blow it using my welder.

Usually air compressor are 220 with a 30 amp breaker. Should be fine.

In the summer I have two window A/C units. The only large draws I have are the stove and dryer. I have fuel oil forced air heating. I may also do some misc welding in the garage but I would just swap the compressor/welder and never run them simultaneously.

 

[trc46]

Yeah it should be 220

 

[Tylerc]

You should be fine, just unplug compressor when done with it and you'll never have a problem.

 

[canadianbullitt]

If its 240vac compressor, it not going to draw too much in terms of current. Make sure you follow your local electrical codes since you cant just add a breaker thats the same size as the motor calls for.

What are you wanting to install?

 

[RDJ]

Yeah it should be 220

it depends on the compressor. Mine is a 80gal 7.5 hp and rated at 230v there are others that are 240v which means they will operate from approx. 208-240v

 

[Mr. Mach-ete]

You have enough spare room at the bottom for a double pole breaker. Does the air compressor call for 30 amp service? seems high. I would think 20 amps would be sufficient. Do you have electrical specs on unit?

 

[Tylerc]

It may draw max twenty amps but i bet breaker size is one higher

 

[mcallister]

Are you sure you have 240v going to your sub panel?

 

[RDJ]

Are you sure you have 240v going to your sub panel?

you don't need "240v" going to the panel. you need to be sure the panel is rated for the number of amps you run off of it. if it is a 100amp panel for example and adding the 30 amp appliance to it puts the pull at the panel to 130+ amps then the panel will likely need to be replaced with a bigger one. you get the 240v outlet by placing 1 240v breaker or 2 120v breakers with the required amprage rating in the panel.

 

[Tylerc]

All subpanels are fed with 220 in canada can't believe its any different down there.

 

[mcallister]

you don't need "240v" going to the panel. you need to be sure the panel is rated for the number of amps you run off of it. if it is a 100amp panel for example and adding the 30 amp appliance to it puts the pull at the panel to 130+ amps then the panel will likely need to be replaced with a bigger one. you get the 240v outlet by placing 1 240v breaker or 2 120v breakers with the required amprage rating in the panel.

I'm aware of this. He still needs 240v at his panel to run a 240v compressor. I was just making sure whoever did the sub panel didn't only do a 120v service thinking they would never need 240v. Reading is better than me...I thought that was his sub panel he wanted to run it off.

 

[mcallister]

All subpanels are fed with 220 in canada can't believe its any different down there.

Not here, I've only got 120 going to my garage.

 

[Mr. Mach-ete]

Review the nomenclature on the compressor to determine the minimum and maximum voltage and ampacity ratings.

 

[mcaligiuri]

I got a air compressor a couple of months ago. Still trying to save up to piece it all together. Just got a sub panel for Christmas that I'm gonna install. If I were you and had a garage run a 60 amp sub that way you don't use too many breakers for one area. And the sub panel can feed the whole garage and you only lose a double breaker spot in the main.

 

[siLversLeigh]

you don't need "240v" going to the panel. you need to be sure the panel is rated for the number of amps you run off of it. if it is a 100amp panel for example and adding the 30 amp appliance to it puts the pull at the panel to 130+ amps then the panel will likely need to be replaced with a bigger one. you get the 240v outlet by placing 1 240v breaker or 2 120v breakers with the required amprage rating in the panel.

You do need 240v @ the panel. It's just both legs coming from the pole. Op would have pull the cover off and put a meter across both legs to verify 240v. I'd be surprised if it wasn't.

Motors need to be fed within 10% of their rated voltage.

 

[Jon82387]

Ok a couple things.... Being this is your main panel you should definitely have 220-240 available.

There are already double pole breakers in the panel.... So you should be fine.

And yea just find out what kind of compressor your gonna get then look the data up from the manufacturer. Install the size breaker they call for, and yea just set your welder up with the same plug and plug/unplug whatever one you are going to use.

Only problem you may ever have is if you have both a/c's running, your dryer, and hot water tank. Then try and make a huge weld or run the compressor for long periods that could possibly trip the main breaker..... But I doubt it would ever happen.

Good luck!