80 gallon compressor, replace motor or buy new

[espolebarn]

Long story short, a friend offered to sell me an unused but older 80 gallon black max air compressor for my shop. He said take it and try it before I pay. I plugged it in and the motor threw sparks. Took the motor to an electrician said it looked like water had dripped on it over the years and thats why it was fried.

so my question is, Friend dropped price to $250 for the tank if I still want it and I would have to buy new motor. Old motor was 6.5hp 230v 22amp. The 80 gal is overkill for my shop but I thought it would be nice to have anyway. I see tractor supply has a 6hp 23amp motor (same make for $229) with year warranty

Do I spend the $500 total to get this running, or do I spend ~$400 for a jobsmart style that is half the capacity but brand new. (mainly airtools etc, no lift)

Also, right now I only have 12AWG run to the 220v outlet, it is a short run, but I guess that wire is only rated for 20 amps. Could that handle the load of that 6hp 23amp motor? or could the 2 stage pump on the black max run with a 5hp 19v motor (same price at tractor supply)

I guess I could spend double and buy a baldur motor too...

What would you all do?

 

[Stepside]

I have a 60 gal. and wish I had an 80g. Less cycling On-Off.
I wonder what the inside of that 80 gal. tank looks like.
With air compressors: Bigger is Better and Newer = no headaches.
What's your time worth & how long do you want to play with .. Fix-it

Gee, I see you are in Maryland & I'm in NW NJ.
If you were closer, I'd sell you mine 5hp 60g for $250
and put the money toward the purchase of a new 80g unit.

 

[pattenp]

If it's a 2 stage compressor and you know the pump and tank are in good shape then it's worth it. If it's a singe stage I would have to think hard about it. When you say unused, just how old is it? Sitting unused for years is not good.

 

[espolebarn]

It is a 2 stage

I guess I should stick a flashlight in the tank hole and check it out, the tank does look in good shape from the outside, its just been sitting in a barn for 5-6 years.

The air pump seems wheel seems to spin good by hand.

Stepside, sure does sound like a good deal, I have been watching craigslist and haven't seen a 60 that cheap. Sadly i'm out of the country for another month for work. I figured it was a good time to think about what to do while I sit here.

 

[Zrexxer]

Just my opinion of course, but spending $500 and having that compressor running will be an investment in a tool that should last you decades. Buying any new compressor that you can get for $400 is going to be throwing money away on a disposable commodity.

 

[espolebarn]

Ok, sounds like I will keep it.

can I get away with a 5hp 19amp so I can stay below the rating of my wire?




Should I spend double on a baldor motor vs this one at tractor supply (mangetek or something like that with year warrany)

 

[wyliesdiesels]

Long story short, a friend offered to sell me an unused but older 80 gallon black max air compressor for my shop. He said take it and try it before I pay. I plugged it in and the motor threw sparks. Took the motor to an electrician said it looked like water had dripped on it over the years and thats why it was fried.

so my question is, Friend dropped price to $250 for the tank if I still want it and I would have to buy new motor. Old motor was 6.5hp 230v 22amp. The 80 gal is overkill for my shop but I thought it would be nice to have anyway. I see tractor supply has a 6hp 23amp motor (same make for $229) with year warranty

Do I spend the $500 total to get this running, or do I spend ~$400 for a jobsmart style that is half the capacity but brand new. (mainly airtools etc, no lift)

Also, right now I only have 12AWG run to the 220v outlet, it is a short run, but I guess that wire is only rated for 20 amps. Could that handle the load of that 6hp 23amp motor? or could the 2 stage pump on the black max run with a 5hp 19v motor (same price at tractor supply)

I guess I could spend double and buy a baldur motor too...

What would you all do?

Compressors are considered a continous load so the circuit feeding them is sized at 125% of FLC. So u would need #10 wire and a 30a breaker! 23a x 125%= 28.75a. Regardless though, the compressor rating is already over 20a so we know that the next higher circuit size is required without doing the math!

 

[zcar751]

+1 on wylie's comment on wiring requirements. A smaller motor may work temporarily but you will cause it to cook itself from constant overheating.

 

[Aceman]

Compressors are considered a continous load so the circuit feeding them is sized at 125% of FLC. So u would need #10 wire and a 30a breaker! 23a x 125%= 28.75a. Regardless though, the compressor rating is already over 20a so we know that the next higher circuit size is required without doing the math!

A 5 HP motor draws 28 amps by the NEC tables. That requires a minimum 35 amp breaker.

 

[PT Doc]

My Baldor 5 hp states 23a on the plate. Quincy reommended that I use a 50a breaker.

 

[Stepside]

On second thought . . . since you said it is a two stage
A 2-stage will pump less hot air into the holding tank
thereby, reducing the amount of condensation that would occur
if it were a single stage.
Magnetek is by Century Electric.
Also, look at Emerson Electric Motors for air compressors. About $300+
Get or borrow an LED inspection probe. The tank is probably good.

A two stage compressor new is about $1400+.

 

[wyliesdiesels]

A 5 HP motor draws 28 amps by the NEC tables. That requires a minimum 35 amp breaker.

Which tells us that if the FLC is correct on the nameplate, then the stated HP is BS. And we both know that many motor manufacturers grossly overrate the HP rating of their motors!

My Baldor 5 hp states 23a on the plate. Quincy reommended that I use a 50a breaker.

That would be overkill!

 

[uniballer]

Hell you pay for shipping, I will give you a one horse motor for it!

 

[espolebarn]

Could a smaller motor run it? (like the 1hp you said or even a 5hp) Someone stated above that it would burn the motor up. Is that still true being its a 2 stage?

I wish I knew more about this, glad you guys can help.

or should I spend the $$ of some heavy wire and re do it, right now the wire is ran in the walls. I do have 100 amp service.

I really dont want to rerun a heavier gauge wire, would be a real pita now that insulation is up. Right now I have 12 on a 20 amp breaker.

 

[pattenp]

Compressors of that size require a certain size motor capable of running the pump. If you look at compressors of the same size with a two stage pump you'll see that they are rated 5hp to 7.5 hp with all of them for the most part taking more than 20 amps to run. It's an expensive gamble to use a smaller motor because I believe the smaller motor won't handle the load and will not last.

Here's a cheap 5hp motor at Northern Tool that's listed at 15A.

Edit: I was looking at the wrong spec. It's a 22 amp motor.

http://www.northerntool.com/shop/tools/product_200596343_200596343

 

[LG63]

Could a smaller motor run it? (like the 1hp you said or even a 5hp) Someone stated above that it would burn the motor up. Is that still true being its a 2 stage?

You should be able to get it down to 3 HP by slowing down the pump (smaller motor pulley) and reducing the cutout setting on the pressure switch. Not all pressure switches are adjustable however.

Manufacturers do this all the time. You will see the same pump running at different speeds with different motors.

 

[BDT/NWMN]

My Baldor 5 hp states 23a on the plate. Quincy reommended that I use a 50a breaker.

Same here... My 80 gallon two stage cast iron pump Sanborn has a 230volt /22amp/single phase motor with a magnetic starter..... I purchased a 30amp breaker and ten gauge wire........... Glad that I read ALL THE INSTRUCTIONS that came with the compressor BEFORE I wired it..... Back to the store for the RECOMMENDED 6 gauge wire and a 60 amp breaker!!!! On start up, Those motors do not like the voltage drop caused by too small wires...... Been running about 15 years... Not one ounce of trouble........

Download the manuals for your compressor... They contain info that is easy to overlook... Your compressor sounds like a keeper.. Should run for decades if properly wired with a good quality motor.... enjoy

 

[Kevin C]

Might be worthwhile to get a quote for geting the motor rewound. I have never had a motor that size rebuilt, but for a few cases at work rewinding saved a pretty good chunk of cash.

 

[wyliesdiesels]

Same here... My 80 gallon two stage cast iron pump Sanborn has a 230volt /22amp/single phase motor with a magnetic starter..... I purchased a 30amp breaker and ten gauge wire........... Glad that I read ALL THE INSTRUCTIONS that came with the compressor BEFORE I wired it..... Back to the store for the RECOMMENDED 6 gauge wire and a 60 amp breaker!!!! On start up, Those motors do not like the voltage drop caused by too small wires...... Been running about 15 years... Not one ounce of trouble........

Download the manuals for your compressor... They contain info that is easy to overlook... Your compressor sounds like a keeper.. Should run for decades if properly wired with a good quality motor.... enjoy

That was a waste of money unless youre using the outlet for something else as well! That compressor only requires #10 wire.

 

[BDT/NWMN]

That was a waste of money unless youre using the outlet for something else as well! That compressor only requires #10 wire.

The instructions were very specific on the recommended wire .....and The compressor is less than six feet from the breaker panel... difference in wire cost?? not very much... My compressor is hardwired to it's own dedicated circuit...

 

[wyliesdiesels]

Doesnt mean theyre right!

 

[K2Orion]

replace the motor and keep the compressor
even with what you will have invested, you could sell it and get your money back
then plug it in to your existing outlet and try it
if it pops the breaker, upgrade
but you might get way with what you have

 

[espolebarn]

Thanks K2Orion,

Thats what a couple friends said to do as well. But new motor, try it first, see if it pops on startup, if so I will just run new wire and be done with it.

Thanks for all the help guys!