Replacing Compressor motor

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cjarrett
Posts: 6
Joined: Wed May 30, 2012 10:54 am

Replacing Compressor motor

Post by cjarrett »

I have a very small shop, 1 car, with a small attached shop, same width, about 6 feet deep. I have a 3-1 Lathe/Mill from Grizzly, it's not bad. Drill press, big tool chest, cabinets etc... so space is limited.

I have a 30 gallon compressor, this one: http://www.chpower.com/productdetail/au ... sor_vt6358

Built it a nice enclosure with intake and exhaust etc... insulated for sound somewhat.

It's a 110v 2hp motor. I now have 220 in my shop, is there any reason I can't get a 5hp motor and run it off 220v in the shop to be able to re-fill the tank faster? I really don't want to go out and get a whole new compressor, but need more air.

Thanks,
STRR
Posts: 469
Joined: Thu May 24, 2007 9:01 pm
Location: Westminster, CO

Re: Replacing Compressor motor

Post by STRR »

This will be a very basic answer.

You can well replace the motor with a 5hp 220v model BUT, the output of the compressor is based on piston size and RPM. If the motors have the same rpm, and they most likely will/should, the discharge rate and recovery time will be pretty much the same. I would not recommend using a higher rpm motor as the compressor end is probably rated for the original motor.

The opposite side of recovery is storage. Adding extra storage will increase recovery time but will increase run time as well. That's if you have the room. I know you said you had a small area.

Please remember this is a basic explanation. There are other minor contributing factors but rpm is the key in motor replacement. If the rpm drops significantly when pressure rises, a large motor usually will help there. Usually, this is not the case.

Good Luck,
Terry Miller
redneckalbertan
Posts: 1274
Joined: Thu Nov 01, 2012 10:39 am
Location: South Central Alberta

Re: Replacing Compressor motor

Post by redneckalbertan »

Shure you can replace the 2 horse with a 5 horse. If nothing else changes I don't think you will notice any difference.

If you do increase the horse power of the motor you might want to concider changing pulley sizes and run the compresser a little faster, if it is rated for it.
Ike
Posts: 138
Joined: Fri Dec 16, 2011 12:48 pm
Location: Sequim, Wa. USA

Re: Replacing Compressor motor

Post by Ike »

The increased HP won't increase the output of your compressor pump unless the current
motor lugs down as it fills the tank at the upper end of it's pressure range.
As STRR said, your compressor output is a function of rpm & cylinder displacement.
You can gain faster recovery and an increase in cfm by going to a slightly
larger motor (2 1/2 - 3 HP) and a larger motor pulley, as redneckalbertan suggested,
but the change will result in a shortened pump lifespan, much shorter if you run the pump
faster than it's rated RPM.
You would be better to replace the pump with one that has a larger displacement, but that would
most likely require a larger motor to run properly.
cjarrett
Posts: 6
Joined: Wed May 30, 2012 10:54 am

Re: Replacing Compressor motor

Post by cjarrett »

Thanks everyone.

I was looking into pumps as well as motors, and the combination of the two just doesn't make sense money wise. I can buy a brand new 60 gal compressor with 15+ CFM @ 90 for less than the pump + motor would cost.

I wish I could install it outside, but then the noise would be louder for my neighbors and couldn't run it at night, which I can now in it's enclosure. Underground? :)
hammermill
Posts: 2938
Joined: Sun Jun 27, 2010 10:43 pm
Location: pendleton or

Re: Replacing Compressor motor

Post by hammermill »

try muffling the air intake with maybe a couple large car oil type filters, you may be suprised how much quieter things get

most of the noise is from the reeds or valves opening.

and yes often time new is cheaper than parts, they compete in differient pricing schemes.
rustyh
Posts: 326
Joined: Tue May 01, 2012 1:21 pm
Location: Hornby Island, B.C., Canada

Re: Replacing Compressor motor

Post by rustyh »

I know nothing about compressors, however my large compressor died. It's old, and the former owner's son stored it outside with the oil input cup having no top, with the compressor stored under a waterfall from the eaves. I got it for a song and drained and replaced the oil until everything ran clear, about 8L worth. It ran for me for 6 years, then last year it slowly died.

When I asked the C/E on our ship about getting a new compressor, his advice was to rebuild the one I have, it's built like a tank and his opinion was the new compressors are junk, essentially throw away's when they pack it in.

Someday I'll take his advice, I've too many things going on at the moment, and my little nail gun compressor is doing the job when I need air, still....the sandblasting cabinet is standing forelorn.... :(
DeMaxx
Posts: 97
Joined: Wed Jan 30, 2013 10:51 pm

Re: Replacing Compressor motor

Post by DeMaxx »

I bought one of these from Harbor Freight 6 or 7 years ago and it has served me well. I use it pretty much every day.
http://www.harborfreight.com/145-psi-5- ... 67698.html
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