Ingersoll rand Compressor wiring question

[Certified]

hi guys,

i am about to to buy an Ingersoll rand compressor 2340L5, it is a 5HP, 60 gallon, single phase, two stage. i went to ingersoll rand store today to get more info about the amperage, on the tag it shows 230V but only an (*) where the amperage rating should be. the tech did not give me a clear answer about it, he said all depends on the circuit your have!!!!

I dont have an existant circuit in my attached garage, so i am about to add a dedicated one, so from what i read in the other threads i am safer to go with a 30AMP breaker and a 8/2 or 8/3 wire, my run would be about 65 feet long.

now here is my biggest confusion:
i cannot find an 8/2 wire only 8/3 available so if i go with an 8/3 wire where does the ground go? the receptical has only 3 prong (2 hot and a neutral) and the compressor wire got also 3 wires, (2 hot and neutral/ground) would it be the receptical box it self?

i spent 2 hours between home depot, lowes, and rona no one can give me a clear strait answer.

my panel got one slot for grounds, one for neutrals and of course the 2 hot go to the breaker but when i get to the receptical side that has only 3 prong i am left with the ground hanging!!!

here is the plug i am using or similar:

i dont have the service manual of the compressor and the amperage on the compressor is unknown!

please help
thanks

 

[Stuart in MN]

At the receptacle you use the two hots and the ground wire, not the neutral. Just put a wire nut on the end of the neutral wire and leave it loose inside the box.

A 5hp motor will have a full load amp rating of about 28 amps, so a 30 amp breaker isn't big enough (assuming it's an actual 5hp motor) - I'd use a 50 amp breaker with the #8 wire.

edit: of course, a 50 amp receptacle would be required as well.

 

[Gary S]

I see a lot of "supposedly" true 5hp motors with nameplates that show 22-24 amps running on 240. The nameplate on his motor should have this information. These motors run very well on a 30 amp breaker.

 

[JakeKohl]

At the receptacle you use the two hots and the ground wire, not the neutral. Just put a wire nut on the end of the neutral wire and leave it loose inside the box.

A 5hp motor will have a full load amp rating of about 28 amps, so a 30 amp breaker isn't big enough (assuming it's an actual 5hp motor) - I'd use a 50 amp breaker with the #8 wire.

edit: of course, a 50 amp receptacle would be required as well.

I've got a 7hp, 80gal Ingersol Rand compressor (175psi) running on a dedicated 2 phase 220v 20amp circuit...on a 30amp outlet/plug. been that way for years with no problem and no trips.

 

[ishiboo]

hi guys,

i am about to to buy an Ingersoll rand compressor 2340L5, it is a 5HP, 60 gallon, single phase, two stage. i went to ingersoll rand store today to get more info about the amperage, on the tag it shows 230V but only an (*) where the amperage rating should be. the tech did not give me a clear answer about it, he said all depends on the circuit your have!!!!

I dont have an existant circuit in my attached garage, so i am about to add a dedicated one, so from what i read in the other threads i am safer to go with a 30AMP breaker and a 8/2 or 8/3 wire, my run would be about 65 feet long.

now here is my biggest confusion:
i cannot find an 8/2 wire only 8/3 available so if i go with an 8/3 wire where does the ground go? the receptical has only 3 prong (2 hot and a neutral) and the compressor wire got also 3 wires, (2 hot and neutral/ground) would it be the receptical box it self?

i spent 2 hours between home depot, lowes, and rona no one can give me a clear strait answer.

my panel got one slot for grounds, one for neutrals and of course the 2 hot go to the breaker but when i get to the receptical side that has only 3 prong i am left with the ground hanging!!!

here is the plug i am using or similar:

i dont have the service manual of the compressor and the amperage on the compressor is unknown!

please help
thanks

The receptacle has two hots and a ground, it's the white neutral wire you will not use. Cap it off when it enters the panel with a wire nut, and place a wire nut on it behind the outlet. Leave it long enough so that in the future you need it, it's there... since you paid for it!

The compressor takes 28 amps @ 240v. Since you went with 8/3, I would breaker for 40 amps.

 

[79firebird]

If its a true 5 hp you will need a 40 amp braker, Our 5hp compressor at work takes 28.9 amps well running

 

[Rickster55]

Not to hijack this thread but..... If one were to buy the 5hp 80 gallon IR compressor, use a 50 amp breaker with 8/2 or 8/3 wire?

 

[pattenp]

If you use a plug and outlet you need to use #6 Cu for 50A and #8 Cu for 40A and #10 Cu for 30A. If the compressor is hard wired then you can get by with smaller wire to the breaker size based on the NEC requirements for motors. Don't put a 50A outlet and breaker on #8 wire.

 

[Certified]

thanks for the quick replies, actually i dont live in USA i am in Canada, both countries have almost the same electrical code with slight differences, i wish i was in the states you guys got some ridiculous deals on compressors and tools in general.

so after spending an hour looking for some specs on that particular compressor it looks like the motor needs 22.5amp according to US models here is the link:

https://www.northerntool.com/shop/tools/product_200318461_200318461

i am not sure if it is the same model everywhere. i emailed ingersoll rand regarding that, and i am still waiting for a reply. it would be easier if they put detailed specs about their own products, but they don't.

so if this motor is actually rated at 22.5 amps am i safe with a 30amp breaker with a 8/3 gauge? i think, but i am not 100% sure, i am putting a heavier guage only because my run is about 65 feet, just to anticipate any voltage drop , i know that 8 gauge needs 40amp breaker by code, but then again if i put a higher breaker and i have a short, the breaker wont trip, and hello fire department.

I will put a cap on the neutral and use the ground instead from what was suggested, unless if i find an 8/2 wire.

if you guys have any other ideas please let me know.

thanks

 

[EOC_Jason]

It's not really the running current that's the issue, it's the start-up that's the ******... It can actually spike up to 60 amps at start-up for a split-second to get the motor to start spinning. However breakers are designed for X amps for Y amount of time so they won't trip when devices like a compressor start-up initially (or other motors with a load on them).

The proper size for a 5HP motor on an air compressor (pulling around 24 amps) is a 40 AMP BREAKER... It's not to say that you can't squeak by with a 30 amp, but if your breaker starts tripping when your air compressor tries to start up, you will know what is wrong.

 

[JakeKohl]

It's not really the running current that's the issue, it's the start-up that's the ******... It can actually spike up to 60 amps at start-up for a split-second to get the motor to start spinning. However breakers are designed for X amps for Y amount of time so they won't trip when devices like a compressor start-up initially (or other motors with a load on them).

The proper size for a 5HP motor on an air compressor (pulling around 24 amps) is a 40 AMP BREAKER... It's not to say that you can't squeak by with a 30 amp, but if your breaker starts tripping when your air compressor tries to start up, you will know what is wrong.

How am I getting by with a 20amp breaker on a 7hp (2 phase) compressor without issue?

(granted, that 7hp is "peak" and probably a fluffy number...but it's an 80 gallon 175psi Ingersoll Rand).


ahhh, nevermind....I missed the point about his compressor being single phase

 

[79firebird]

Certified its 3.2 hp run 5 hp peak went and looked at one today so a 30 amp will be fine.

JakeKohl no way a 7 hp would start on a 20 a 30 mabey chances are the motor is over rated

 

[Falcon67]

Certified its 3.2 hp run 5 hp peak went and looked at one today so a 30 amp will be fine.

JakeKohl no way a 7 hp would start on a 20 a 30 mabey chances are the motor is over rated

My real 3.2HP 60 gallon uses 12 gage wire on a 20 amp 240V run. That's right at 10A on 240V, well under the 20A rating for the wire and breaker. I don't know what the spike current is, but it doesn't affect the breaker.

 

[Stuart in MN]

How am I getting by with a 20amp breaker on a 7hp (2 phase) compressor without issue?

(granted, that 7hp is "peak" and probably a fluffy number...but it's an 80 gallon 175psi Ingersoll Rand).

ahhh, nevermind....I missed the point about his compressor being single phase

There isn't any two phase...assuming your compressor runs on 240vac and there are two hot wires, it's single phase. Same thing with the original poster's compressor - 240vac, two hot wires, single phase.

That 7hp 'peak' value is a good example of why you can't necessarily go by advertised horsepower ratings for sizing the electrical circuit, you have to go by the actual full load amp rating of the motor.

 

[JakeKohl]

fair enough (I'm proving my lack of knowledge here)....but still....I can't believe he needs a 40 or 50 amp circuit.

This is my compressor that runs on a 20amp 240v circuit. I sized the circuit based on information from Porter Cable when I installed it. I have never had a tripped breaker and I use the **** out of this thing from time to time (sandblasting, etc.).


DSC_3104 by Team Seacats, on Flickr


DSC_3091 by Team Seacats, on Flickr

 

[burleyfarm]

I have the same IR compressor that Certified has only with an 80 gallon tank. I don't have the owners manual with me but I remember that I needed a 40 amp breaker and 8/3 wire. I just bought the compressor and associated wire and breakers so I'm sure of the size. I believe the need for the 40 amp vs 20 or 30 has to do with the amount of amps used at start up. My electrician friend that is doing the hookup said it was not safe to put a 50 amp in.

I'm having mine wired direct, no plug, with a second 40 amp breaker in a sub panel next to the compressor.

 

[EOC_Jason]

What's interesting is different breaker brands are spec'ed to "hold" longer and higher amps than others. For instance, I had a 3-phase motor on a 100 AMP GE breaker, ran fine for years. Had to move the setup elsewhere, and it got hooked up to a 100 AMP Square-D breaker. Kept tripping the thing every time you tried to start it. We trouble shooted the heck out the thing till we discovered that the Square-D are not rated as high / long of a start-up (inrush) current as the GE. It's only a fraction of a second, but that fraction of a second made the difference. We couldn't put a 125 AMP in the panel so we ended up using a 100 AMP fused (slow blow) disconnect box... Has worked fine since.

That is kind of the same for a compressor. That initial start-up has to overcome the inertia of the motor and pump standing still. Likewise if you put a clamp-on meter you will see the current slowly increase with the pressure (because the pump is having to work harder)...

 

[79firebird]

JakeKohl could be the differnece between real motors and the ones these compressors have. the 5 hp 220 motor we have at work is bigger then the one on your compressor. our 10 hp one is almost 16 inches around and weighs 190 pounds. our 5 hp one weights about 150

 

[Certified]

ok guys, major change here, i finally gave up on ingersoll rand people, they got no stock and do not reply to emails, i am pretty disappointed on these people, so instead i got this speedair compressor:

it is a 60 gallon, 2 stage, 1 phase, 5HP according to the manufacturer BUT here again another confusion on the motor sticker it shows "SPL" instead of HP, and 21amp as you can see. and on the tank's sticker it says 27AMP for canada code.

i am still gonna wire it the same way but what the heck is "SPL" is it "special" ? why is everything confusing with these damn compressors.

i got it for 500$ and it is in an excellent shape, the guy who sold it to me painted his car with it and he did an awsome job, he said he used it only once so i am assuming it is almost brand new.

here is the description of the mafacturer:
http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=3JR76&op=search&Ntt=3JR76&N=0&GlobalSearch=true&sst=subset

do you guys have any idea what SLP means? and why the amperage is different between the motor and the tank?

thanks

 

[Canadian Cowboy]

This compressor needs a 30amp breaker as the full load amperage draw is higher than the normal operating amperage.
The reason for the SPL instead of a actual HP rating on a electric motor is because the electric motor is made with low grade windings,etc.
A quality electric motor/air compressor pump combination the electric motor will have a rpm range of 1725-1750 and the electric motor nameplate will have all the specs on it including HP,FLA,etc.
I posted the information a while back for another member.
http://www.garagejournal.com/forum/showthread.php?p=2336042#post2336042
http://www.wisedan.com/aircomp

CC

 

[Bob C]

here is the description of the mafacturer:
http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=3JR76&op=search&Ntt=3JR76&N=0&GlobalSearch=true&sst=subset
thanks

A side note here. That unit is not manufactured by Grainger. It is manufactured by Campbell Hausfeld and private labeled for Grainger. It uses a quad pump design and those ratings on the tank are legit.

 

[Norcal]

There isn't any two phase...assuming your compressor runs on 240vac and there are two hot wires, it's single phase. Same thing with the original poster's compressor - 240vac, two hot wires, single phase.

That 7hp 'peak' value is a good example of why you can't necessarily go by advertised horsepower ratings for sizing the electrical circuit, you have to go by the actual full load amp rating of the motor.

There actually is 2 phase power, it is obsolete but is still in use in some cities like Philadelphia, but I concur that the poster who said it was "220 2 phase" does not have it....

 

[Certified]

alright guys i finished wiring my compressor, so i finally i ended up putting a 50amp receptical and plug, 8/3 wire all the way to my panel, and 30amp breaker, and it works like a charm i changed the pressure gauge, the one that came with the compressor was not working.
and i am pretty happy with the results here is the final result

i was pretty impressed with the noise level comparing to the crappy oiless compressor that i used to have, 85dB @10 feet away from the compressor.

anyway i would like to thank all of you who contributed to this thread, your ideas helped a lot.
thanks

 

['04 Cummins]

You really aren't supposed to use a 50 amp receptacle wired to a 30 amp breaker. A 30 amp breaker requires a 30 amp receptacle. OTOH, good labeling!

 

[pattenp]

That's what I use to think too until I was convinced otherwise in a different thread discussion. NEC only says you are not to put a smaller amp rated receptacle than the circuit amps it serves, such as a 30A rec on a 50A circuit. The only thing is the discussion is about welders.

You really aren't supposed to use a 50 amp receptacle wired to a 30 amp breaker. A 30 amp breaker requires a 30 amp receptacle. OTOH, good labeling!

 

[Certified]

You really aren't supposed to use a 50 amp receptacle wired to a 30 amp breaker. A 30 amp breaker requires a 30 amp receptacle. OTOH, good labeling!

the opposite would be true, since the motor was a 21amp only i was required to put a 30amp receptacle / 10awg / and 30amp breaker by code, but i used a 50amp receptacle, 8 awg and a 30amp breaker. as long as it meets or exeeds code requirement nothing is wrong.
at least i know that my wires wont run hot and will never have voltage drop, and my compressor will always run at its max performance, and when i decide to upgrade to a more demanding compressor i dont have to redo everything again, i will only change the breaker.
i put labels so my wife wont try to plug the toaster there

 

['04 Cummins]

the opposite would be true, since the motor was a 21amp only i was required to put a 30amp receptacle / 10awg / and 30amp breaker by code, but i used a 50amp receptacle, 8 awg and a 30amp breaker. as long as it meets or exeeds code requirement nothing is wrong.
at least i know that my wires wont run hot and will never have voltage drop, and my compressor will always run at its max performance, and when i decide to upgrade to a more demanding compressor i dont have to redo everything again, i will only change the breaker.
i put labels so my wife wont try to plug the toaster there

I searched the code and I stand corrected. But, in my jurisdiction, the receptacle rating must match the breaker rating. At least this is what I have heard from a couple of electrical contractors.

 

[Al Bundy]

I don't know about the receptacle having to match, but I thought 50 amps required #6 wire. If you do upgrade in the future to a 50 amp circuit the wire is inadequate.

 

[Certified]

I don't know about the receptacle having to match, but I thought 50 amps required #6 wire. If you do upgrade in the future to a 50 amp circuit the wire is inadequate.

i dont think i will ever need a heavier gauge than an 8AWG, my compressor required a 10AWG only but i used an 8 just because most heavy duty tools under 220V will not go over 8 gauge thats why i didnt bother with a 6AWG, the only thing i would think of is a welder, but i already have one.
the 50Amp receptacle was a better deal pricewise thats why i got it, but i can change it anytime, just remove the face plate and put a 30amp, it takes 10minutes.

 

[sberry]

Look on a 50A recept some time, some are rated for 12 wire, all of them list 10, you will never heat an 8 on an air comp or welder with 50A, about the only possible thing i can think of that needs a 6 on this type of circuit at home would be pottery kiln or some kind of oven.