Air compressor wiring question

[bionicbelly]

First post, long time lurker, short time member. Hi all.

I just got done putting a sub panel in my garage, because I got some new equipment. I had to get 220 out to the garage, because the wheel balancer I got needed that.

My main problem is the main service for our house is 100 amp, so my main goal is to keep amperage down as much as possible.

I ran 220 out to the new box with a 30 amp breaker. Out of the sub panel, I have a 15a 220 circuit for the balancer and a 15a 110 circuit for the lights, garage door opener, tire machine, welder, and all the outlets.

I just got a new puma 110 air compressor (link) and want to hardwire it into my 15a 220 circuit to lower amps needed, and keeping it from killing my 110 circuit every time it kicks on. I can control using only one 110 piece of equipment at a time, but with the compressor kicking on randomly, it makes it more difficult.

The compressor says it can run on 110 or 220, and there are schematics in the reset switch and pressure switch covers, but I don't get it. I have searched and searched, but can't seem to find what I need to do to convert this thing over to 220. If anyone can help me out it would be appreciated.

FYI- tire balancer is 220v - 3amp http://www.hunter-d.de/us/product/products/wb/5358te-05/index.htm

Tire machine is 110v 15a http://www.ammcoats.com/baseline-tire-changer-model-bl400

Compressor is 15a at 110, 7.5 at 220.

 

[pattenp]

First thing, just because your main panel is 100A doesn't mean you can't do larger than 30A to the sub-panel. You can do more if you want. Should have done outlet circuit as 20A. But, that's water over the dam.

Changing the compressor to 230V should be easy. Post a picture of the wiring schematics and someone will help you.



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[PetesPonies]

The overall load on your circuit is not going to change by going 220V.

 

[pattenp]

The overall load on your circuit is not going to change by going 220V.

Yep.. watts is watts. The lower amps @ 230V only means you can use smaller wire.

 

[Ross/Kzoo]

@ 110 volts you have 15 amps but may have an initial surge higher than that. I would change the wiring to 220. Usually you just need to change a wire from one terminal to another in the box mounted on the motor.

 

[bionicbelly]

Patten - I thought amps was what pops the breaker. This is all I am trying to avoid. I'm not really worried about consumption, just trying to run stuff without bogging down.

Before I did all this, everything in the garage was coming out of a single 15a breaker, and when I would turn something on, lights would dim, compressor and tire machine would bog down, etc. Not surprising, since whoever wired the garage to begin with ran all new wire, except for the five foot chunk that went up the wall from the basement to junction box before the weather head. That was some sixty year old asphalt covered stuff, and was kinda toasty when I pulled it out. (I put in 10ga wire to the new panel)

Anyway, here are some pictures of what I have.

under the reset switch panel on the motor
[URL=http://s271.photobucket.com/user/gratefulbelly/media/20141123_181533.jpg.html] [/URL]

Wires in reset switch box on the motor:
[URL=http://s271.photobucket.com/user/gratefulbelly/media/20141123_1816281.jpg.html] [/URL]

Diagram under pressure switch cover where power cord is connected

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Wires in pressure switch box

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Thanks for all the responses so far.

 

[bionicbelly]

So, I am pretty sure I can just hook up hot to black and white, and ground to green in the first box (pressure switch box), but I am not sure what to do in the reset switch box that is on the motor.

One more question, since I plan to hard wire this thing, should I just cut the plug off and use the cord that came with it, or should I get some of that flexible metal conduit stuff and wire it it up with that?

 

[PetesPonies]

Why are you insisting on hard wiring it? More flexibility if you leave it a plug.

 

[bionicbelly]

I am planning on putting the compressor in the corner behind the balancer. It will never move, so I don't see the point of putting in another outlet. I only have a small two car garage, so I have to keep stuff as tight as possible.

 

[pattenp]

7 amps at 230V is the same load as 14 amps at 115V. By switching to 230V you are spreading the load across the two legs so the amps are reduced on the one 115V leg/circuit, but the total load is not reduced on the sub-feed. You can balance/spread the load by having more than one 115V circuit by using both legs in the sub-panel. In other words you should have put in two 115V circuits for the outlets, one on each leg.

As to the motor, the motor wires should be black, white, red, yellow. For 110 the red and yellow are tied together with a lead going to the pressure switch and the black and white are tied together with a lead going to the pressure switch. To change to 220 the black and yellow are tied together and the red goes to the pressure switch and the white goes to the pressure switch.

 

[C96]

7 amps at 230V is the same load as 14 amps at 115V. By switching to 230V you are spreading the load across the two legs so the amps are reduced on the one 115V leg/circuit, but the total load is not reduced on the sub-feed. You can balance/spread the load by having more than one 115V circuit by using both legs in the sub-panel. In other words you should have put in two 115V circuits for the outlets, one on each leg.

As to the motor, the motor wires should be black, white, red, yellow. For 110 the red and yellow are tied together with a lead going to the pressure switch and the black and white are tied together with a lead going to the pressure switch. To change to 220 the black and yellow are tied together and the red goes to the pressure switch and the white goes to the pressure switch.

Needs to be re-edited again

 

[pattenp]

Needs to be re-edited again

Okay... care to clarify?


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[bionicbelly]

Also interested in a clarification. Also, am I right when I said that the power cord would be black and white hot, and green ground?

 

[pattenp]

Also interested in a clarification. Also, am I right when I said that the power cord would be black and white hot, and green ground?

Yes, using 3 wire cord for 240V the white and black wires are the hots and green is ground.

 

[C96]

Okay... care to clarify?

Ok, clarification:

pattenp you never addressed re-connecting the overload reset button. This is a must in order to protect the motor and is also an NEC requirement. Also, converting the compressor over to 240 volt operation will reduce the amp draw on the sub-feed which I believe was the OP’s main objective to begin with and reason for starting this thread.

Now, since the compressor was factory wired to operate at 120 volts, that reset button will no longer properly protect the motor if converted to 240 volt therefore a new reset button of the proper rating should be installed, or another means of protecting the motor from overloads.

 

[pattenp]

Well...C96, I didn't address the reset button as I was only explaining the wiring diagram to run the motor @ 240V. If the compressor is listed as running on 110V or 220V then it should be just a matter of changing the motor wiring without having to replace and or rewire the reset button. And as for going to 240V from 120V does reduce the potential of circuit overload vs. using just the one 115V circuit that he currently has. As far as the total load through the sub-panel goes, I was looking at wattage being pulled is the same.

 

[C96]

Sorry pattenp I disagree with you here. Anytime you alter what the factory has built you must take into consideration the ramifications that will take place do to the changes you make. Just because that motor is capable of operating at both voltages, 120 & 240 doesn’t mean you can just randomly change one thing without the other. The factory has specifically wired this particular motor for 120 volt operation and installed the appropriate thermal protector to protect this motor from overloads while operating at 120 volts.

Common now, same as with a 3 phase compressor that has a multi voltage motor and the factory installed a mag starter with overload protection for say 230 volt operation in order to protect it. Now, since your facility has 480 volt capability you decide to wire it at the 480v. Lol…do you mean to tell me that your not going to change the overload protection for the motor operating at the higher 480 volts?

Whether its overload relays installed in a mag starter, or the overload reset button installed on the motor itself, changing the voltage has a direct result on motor overload protection.

 

[bionicbelly]

This is what I got from northstar. (same thing as the puma.)

They did not say anything about the overload switch, so I asked specifically if it needed a different one, but they said no.

 

[pattenp]

Sorry pattenp
...
Common now, same as with a 3 phase compressor that has a multi voltage motor and the factory installed a mag starter with overload protection for say 230 volt operation in order to protect it. Now, since your facility has 480 volt capability you decide to wire it at the 480v. Lol…do you mean to tell me that your not going to change the overload protection for the motor operating at the higher 480 volts?

Whether its overload relays installed in a mag starter, or the overload reset button installed on the motor itself, changing the voltage has a direct result on motor overload protection.

This is way over board as a comparison when talking about a 120/240v home owner type unit. Sheez....

 

[pattenp]

This is what I got from northstar. (same thing as the puma.)

They did not say anything about the overload switch, so I asked specifically if it needed a different one, but they said no.

Just as I figured. You should not have to change anything other than the motor wiring on a home owner type compressor that is made to be dual voltage.

 

[C96]

This is way over board as a comparison when talking about a 120/240v home owner type unit. Sheez....

Lol…just because my example used a 3 phase motor @ 480 volt as opposed to a single phase motor @ 240 volt makes no difference.

The fact is if you double the voltage on any motor that requires overload protection, said protection must be adjusted accordingly.

Makes no difference whether its homeowner or not.

 

[Ross/Kzoo]

What does this have to do with the OP's question? You're just confusing the situation.

 

[wyliesdiesels]

Interesting debate..

Lol…just because my example used a 3 phase motor @ 480 volt as opposed to a single phase motor @ 240 volt makes no difference.

The fact is if you double the voltage on any motor that requires overload protection, said protection must be adjusted accordingly.

Makes no difference whether its homeowner or not.

However, the OP contacted the manu. and no change to te overload/reset is necessary...

 

[bionicbelly]

Well, just an update, Everything worked just fine. I cut off the plug, and hardwired the cord up to 220, ran one hot leg thought the overload switch, one to the white wire, and connected the yellow and black wires. It did not blow up. So, I am chalking it up as a win.

On a side note, this thing is so much quieter than my other compressor! I have been using an 11 gal CH oil less compressor for the last ten years or so. That thing is so F'n loud, it impossible to work around. Very happy with the sound level of this one. It also takes less time to pump up.

 

[wyliesdiesels]

Unfortunately cord is not meant for nor code permitted to be used in a permanent installation...

Cordage is used for portable equipment.

 

[marantzer]

Hi Folks - I have the same compressor (North Star) and am trying to convert over to 220V, here is a picture before:

And here is a picture after:

I have the white wire running from the pressure switch, through the fuse, then tied to the red motor wire. Then I have the black pressure switch wire tied to the white motor wire. The yellow and black motor wires are tied together. Can someone who knows the right way to do this check to see if it's done correctly?

Thanks!

 

[sberry]

As for the 30A feed, I would have put all the stuff you did, lights maybe, light convenience outlets, door opener even on one circuit and another circuit on opposite leg for a 120V 20A tool circuit. Used it for air comp, welding if from 120

 

[wyliesdiesels]

Hi Folks - I have the same compressor (North Star) and am trying to convert over to 220V, here is a picture before:

And here is a picture after:

I have the white wire running from the pressure switch, through the fuse, then tied to the red motor wire. Then I have the black pressure switch wire tied to the white motor wire. The yellow and black motor wires are tied together. Can someone who knows the right way to do this check to see if it's done correctly?

Thanks!

Post a pic of the motor nameplate with the wiring diagram.

 

[marantzer]

Here are a couple more pictures, appreciate you guy's thoughts