Adding a 220v outlet for air compressor question

[spitfire557]

Was recently gifted an air compressor which is 220v so I need to add an outlet to the garage. I just want to make sure I'm doing it correctly and not burn the place down.

I bought a 30a double pole breaker for my sub panel, and plan on running 10/3 to the outlet I've attached. This outlet matches the plug which is already installed on the compressor. I did notice that this outlet is advertised as an air conditioner outlet, and wanted to double check that it's okay to use. If switching to a more preferable plug/outlet is recommended I have no issue with that.

I added a few photos of the plug, wiring, and motor specs. I guess my biggest question is if it's okay to use this 20 amp plug and outlet on a 30 amp breaker. If I stick with a 20 amp breaker, is it possible it'll trip often considering the motor is rated at 15 amps?

Thanks in advance!

 

[London21]

Probably not a good idea. Considering it is always hot, it's not impossible to exceed the rated ampage of the outlet but not flick the breaker due to the 10amp difference. The air compressor motor will only take as much draw as it demands, so even if the outlet is pushing 20 or 30 amps it will still only take 15amps from it. But the outlet isn't smart enough to only take what it can, it will take whatever current is 'forced' at it. That is at least to my understanding there could a aspect of the outlet itself I'm overlooking though.

 

[The Cobbler]

you might be Ok with the plug but a larger motor would need a Horsepower rated plug & receptacle. but the electricians will chime in here I'm sure
you also don't need 3 wire for the 240volt circuit. 2 wire with ground is all you need

 

[u2slow]

I have a Speedaire with the exact same power requirement. I run it on a 20A breaker with #12/2 cable using the 6-20R you pictured. No issues.

 

[spitfire557]

you might be Ok with the plug but a larger motor would need a Horsepower rated plug & receptacle. but the electricians will chime in here I'm sure
you also don't need 3 wire for the 240volt circuit. 2 wire with ground is all you need

The motor is rated at 7hp if it makes a difference. And good call on the 2 wire, I overlooked that.

 

[spitfire557]

I have a Speedaire with the exact same power requirement. I run it on a 20A breaker with #12/2 cable using the 6-20R you pictured. No issues.

I appreciate your response. Is your motor rated at 7hp by chance?

 

[u2slow]

no, it's rated "SPL" and 15A at 240v is perhaps 3hp. Factory 6-20p plug.

 

[Terry D]

That receptacle is not rated for 7hp or the current being used. You will need to hardwire that compressor. Plug and receptacles for that HP are crazy expensive. You would need (2) #8's THWN in conduit with # 10 ground or 8/2 MC cable or #6/2 NM-b feeding it and a 60, 70 or 80 amp breaker. Plus if the panel feeding it is not with in site, you will need a 60 amp disconnect.

 

[u2slow]

That nameplate is not 7hp.... It says 'SPL' in the upper left corner.

 

[Terry D]

That nameplate is not 7hp.... It says 'SPL' in the upper left corner.

The pictures did show up when i posted. Disregard everything i said

Sent from my SM-G960U using The Garage Journal mobile app

 

[AP514]

I would 100% Not run using a PLUG..Just me.

This is what I ran to my Compressor a few years back with the great Help and Advice givin here.....
1) 10/3 solid from Panel to disconnect..(10/3 only because I needs a 120v to a Intercooler fan)
2) 1-30 Amp disconnect....https://www.homedepot.com/p/GE-30-Amp-240-Volt-Non-Fuse-Indoor-Safety-Switch-TGN3321CP/100674081
3) 4 each 10 thwn (Colored) wires to run from the 30 Amp disconnect to compressor.
My Panel was across the room (40 feet)

You can click on my Albums to see some pic's of the install/wiring

 

[joe_padavano]

Do the math. The most HP you will get from 15A at 240V is 2.0-2.5 HP.

 

[mobetta]

you can use that outlet, 10-3 wire and just get a 20 amp breaker if you've already purchased everything.

then youd have a 30 amp 3 wire circuit pulled if you upgraded later, just swap in a 30 amp breaker.

but 12-2 would run your compressor

love the marketing ****- 7HP on a 20 amp plug.....LOL

 

[wyliesdiesels]

Its about 3HP

NEC FLC table amps for 3hp is 17a so...

 

[spitfire557]

Well I'm a bit a dummy when it comes to digesting the specs on the motor, so I apologize for saying 7hp. In all fairness, the side of the compressor clearly says "7hp Peak" LOL.

I did another Lowes run today, and my final plan is to go with 12/2 to the receptacle that I posted in the OP. I picked up a 20 amp double pole as well.

Thanks for the help guys!

 

[alfredeneuman]

Its about 3HP

NEC FLC table amps for 3hp is 17a so...

EDIT: Article 430.6(A)(1)says that when the load on the nameplate is expressed ONLY in amps, the Tables shall be interpolated to find the total.

2HP draws 12A @230V, 3HP draws 17A, so the figure for 15A is about 2.67 HP.

 

[rburke65]

There are all types of electricians....I am of one type.....even I get confused by all this.

 

[wyliesdiesels]

Article 406.3 says that when the load on the nameplate is expressed ONLY in amps, the Tables shall be extrapolated to find the total.

2HP draws 12A @230V, 3HP draws 17A, so the figure for 15A is about 2.67 HP.

yes however the table amps are a bit outdated. all the true 3HP motors i see nowadays are 14-15a FLA on nameplate so....

 

[u2slow]

2HP draws 12A @230V, 3HP draws 17A, so the figure for 15A is about 2.67 HP.

One could also convert the nameplate 2.98kW to HP.

 

[u3b3rg33k]

Well I'm a bit a dummy when it comes to digesting the specs on the motor, so I apologize for saying 7hp. In all fairness, the side of the compressor clearly says "7hp Peak" LOL.

I did another Lowes run today, and my final plan is to go with 12/2 to the receptacle that I posted in the OP. I picked up a 20 amp double pole as well.

Thanks for the help guys!

This isn't your fault, a bunch of the compressor companies got sued a while back for deceptive advertising. it's about time it happened again with all the "6HP peak" shop vacs out there that pull 12A @ 120V. what a crock.


15A @240V = 3.6kW INPUT power
2.98kW /.75kW/HP = 3.97HP OUTPUT power
that means it's an 82% efficient motor, which is plausible. the 7HP marketing number is not plausible.

 

[TRWham]

Article 406.3 says that when the load on the nameplate is expressed ONLY in amps, the Tables shall be extrapolated to find the total.

2HP draws 12A @230V, 3HP draws 17A, so the figure for 15A is about 2.67 HP.

I think you meant to say 430.6. Article 406 covers receptacles, cords and plugs.

 

[alfredeneuman]

I think you meant to say 430.6. Article 406 covers receptacles, cords and plugs.

Yes I did mean 430.6 Sorry
EDIT: 430.6(A)(1)
Where a motor is marked in amperes, but not horsepower, the horsepower rating shall be assumed to be that corresponding to the value given in Table 430.247, Table 430.248, Table 430.249, and Table 430.250, interpolated if necessary

 

[alfredeneuman]

Its about 3HP

NEC FLC table amps for 3hp is 17a so...

You used the NEC tables yourself as an example, and you say they no longer valid?
They are still the rules that are used for wiring.

 

[beelsr]

I have this CH unit with that exact motor. It runs fine on a 20A breaker - hasn't tripped in 20-ish years. IIRC correctly, it was a deal - $300 from harbor freight, delivered.

There was a class action lawsuit maybe 15+ years ago about the HP rating being totally made up. I got a bunch of free tools and hose from it.

You'll want to add a strain relief - like a die-cast non-metallic cable connector - to the power feed coming into the contactor.

Change the oil on the compressor pump. Use synthetic motor oil, 10-30 or 10-40, I forget which but you can download a manual from CH's website. Note that different pump units have different oil capacities. The first time, you'll need to make a little trench with AL foil to drain the oil but then install a brass tube to extend the drain past the mounting plate so it doesn't drip over everything and down the tank.

 

[TractorJeff]

I know I am probably TOTALLY WRONG!
BUT!
If it comes from the Manufacturer with that Cord/Plug on it, I would ASSUME that it is OK to use.
Meaning I would put the corresponding Outlet in.
Even though it says A/C Outlet, remember an A/C has Motors in it!
Also if the wire is going inside the Wall, I would go 10ga for Future Upgrades.
Just saying....

 

[beelsr]

If something electrical comes from a manufacturer with a cord (external or internal) then it has been tested by the manufacturer with that cord and yes, it would be OK. E.g., fluorescent or LED fixtures have wiring that's smaller than 14g but you don't need to change your breaker from a 15a to something smaller.

But... this compressor did not come from the manufacturer with a cord. OP got it from a friend, who had put a cord on it.

 

[quickfarms]

Do you have a better picture of the motor tag?

This picture cuts off the upper left side

 

[beelsr]

Here's mine. Same emerson part number, specs are the same, but my "customer part number" ends in "AV" instead of "A".

 

[Showkey]

I know I am probably TOTALLY WRONG!
BUT!
If it comes from the Manufacturer with that Cord/Plug on it, I would ASSUME that it is OK to use.
Meaning I would put the corresponding Outlet in.
Even though it says A/C Outlet, remember an A/C has Motors in it!
Also if the wire is going inside the Wall, I would go 10ga for Future Upgrades.
Just saying....

Agree the last thing I want is a “small” compressor hard wired.

 

[spitfire557]

I have this CH unit with that exact motor. It runs fine on a 20A breaker - hasn't tripped in 20-ish years. IIRC correctly, it was a deal - $300 from harbor freight, delivered.

There was a class action lawsuit maybe 15+ years ago about the HP rating being totally made up. I got a bunch of free tools and hose from it.

You'll want to add a strain relief - like a die-cast non-metallic cable connector - to the power feed coming into the contactor.

Change the oil on the compressor pump. Use synthetic motor oil, 10-30 or 10-40, I forget which but you can download a manual from CH's website. Note that different pump units have different oil capacities. The first time, you'll need to make a little trench with AL foil to drain the oil but then install a brass tube to extend the drain past the mounting plate so it doesn't drip over everything and down the tank.

I appreciate the info! I didn't even consider changing the oil but I'll be sure to do that.

 

[123Go]

Sounds like my 20gal Eagle porty, has 5hp sticker on side & came with a reg 3 prong HD 115v plug.
I missed out on that lawsuit cash, guess I didn't have enough money to pay attention.
Mine has the 15 amp (SPL) motor so I knew it was 3hp at best when I bought it, my bro being an electrician clued me in how the FLA # tells the tale.
Mines ran off so many different standard 110/115 outlets I couldnt begin to count them all. But you can easily tell she runs a ticks turd faster on a dedicated plug. I have had to unplug stuff at times or she slow started under load even new. Its sort of a power hog for its size imo? Maybe more of a power pig? It never liked ext cords under 10awg.
Had it over 15yrs now, she's finally getting tired & motor definitely earned a nap. New capacitors did nothing to change things she's just tired. It started drag starting a bit this spring, then ran normal for months, thought issue resolved itself now she's back to drag'n **** real bad under a load, like on 105psi start up?
So I had to drop that some to run now & it was 70 not 20 deg here.
But no complaints, we've ran just about everything but a DA on it no problem & its surprised us all more than few times for what it really is. Farm/garage used too so you know its been worked, just an awesome little unit. These V-Twins & (3 Lung "W" pumps like my Puma 60) build pressure fast & they are highly reliable fyi.
I'll put a better motor on it than Eagle slapped on it for, probably a 115/220v because I like that flexibility although I rarely use it elsewhere now I may need too.
Shocking what it sells for these days, I think I gave $350 when I bought it many moons ago.
I see Eagle has changed its 5hp sticker to 3hp now but this is my unit. Certified tanks btw, most portys weren't certified back then.
I wont buy any that aren't certified especially today.

Compressors direct changed name btw. This is their new sight.

https://www.fergusonhome.com/produc...6JJth12a3SB4NIyDvuphy_92z2nDnCQsaAsP4EALw_wcB

 

[BurtEggley]

dual voltage motors have two sets of windings - the windings are in parallel on 120V, and in series on 240V. either way, the windings only see 120V.

above is in a similar thread here on the 220v vs 120v question.