220V Compressor Wiring

[Maticuno]

I just got a new belt drive air compressor to help keep up with my new, bigger shop. The compressor is wired for 110V, but everything I've read says it can also be made to run 220V. The problem is I can't find any resources that show how this is done. The wiring diagram on the side doesn't show how and the manufacturer (Marathon) doesn't have this model listed on their website. Based on what I've seen from other 2HP motors that Marathon produces, I think I just have to isolate the yellow wire pictured. Anyone have experience with this? Hate to blow up the motor on a new compressor.

 

[MTW]

There is a connection tag on the label or on the back of the wiring cover. Pictures please.

 

[pattenp]

If the motor can be wired for 240V then there should be a wiring diagram on the motor to show how. If there is no 240V diagram, then most likely the motor can not be wired fir 240V. Do the instructions that came with the compressor state that it can be wired for 240V?

 

[Maticuno]

This is the only diagram on the motor and all it shows is L1 and L2 connections. It doesn't show any of the other internal connections.

 

[pattenp]

What does the motor data plate show for the voltage and amps listings? What is the brand and model of the compressor?

 

[Maticuno]

Central Pneumatic 2HP 29 gallon.

 

[wyliesdiesels]

Take a pic of the motor nameplate and post it here

 

[justsam]

Do you already have an existing 240VAC receptacle and location for the compressor?

What is the desire to convert to 240VAC? Assuming proper wire gauge to receptacle and cord on compressor, it will be fine on 120VAC. It would be best to have it on it's own circuit since it will no doubt draw about 12Amps running.

 

[KenC]

I looked at the HF (Central Pneumatic's seller) website for 29 gal compressors. They have two, neither are 240v capable. Both are 120v only and come with a molded plug for that service.

 

[Stuart in MN]

What is the desire to convert to 240VAC? Assuming proper wire gauge to receptacle and cord on compressor, it will be fine on 120VAC. It would be best to have it on it's own circuit since it will no doubt draw about 12Amps running.

Agreed - there's no advantage to switching it to 240vac.

 

[Maticuno]

My desire to switch to 220 was just for load balancing. My shop has it's own sub-panel and the startup on 110 dims the lights. The compressor is currently wired into a dedicated 50A 220 circuit, just minus one of the hot legs.

 

[pattenp]

My desire to switch to 220 was just for load balancing. My shop has it's own sub-panel and the startup on 110 dims the lights. The compressor is currently wired into a dedicated 50A 220 circuit, just minus one of the hot legs.

That statement raises some red flags.

 

[CNGsaves]

Wanting 240v for a 2 HP 29 gallon Harbor Freight air compressor doesn't quite make sense??

That little compressor will barely put a load on 15 amp circuit on 120v . . . other than jerry-rig a 240v run you already have, I sure wouldn't mess with 240v for that little compressor.

Keep that 240v run just like it is (. . . but un-used) as someday you may have a large 240v compressor that really needs that circuit.

Put cord on that little compressor and plug into 120v outlet !!

 

[pattenp]

Wanting 240v for a 2 HP 29 gallon Harbor Freight air compressor doesn't quite make sense??

That little compressor will barely put a load on 15 amp circuit on 120v . . . other than jerry-rig a 240v run you already have, I sure wouldn't mess with 240v for that little compressor.

Keep that 240v run just like it is (. . . but un-used) as someday you may have a large 240v compressor that really needs that circuit.

Put cord on that little compressor and plug into 120v outlet !!

The compressor the OP has should be corded with a 120V plug. I hope he has not wired a 15A 120V outlet off one side of the 50A 240V circuit.

 

[wyliesdiesels]

My desire to switch to 220 was just for load balancing. My shop has it's own sub-panel and the startup on 110 dims the lights. The compressor is currently wired into a dedicated 50A 220 circuit, just minus one of the hot legs.

Thats a bad idea!

 

[G_P]

My desire to switch to 220 was just for load balancing. My shop has it's own sub-panel and the startup on 110 dims the lights. The compressor is currently wired into a dedicated 50A 220 circuit, just minus one of the hot legs.

What?
You have a 15a cord hooked to a 50a circuit? If something goes bad, that motor or cord will catch on fire instead of tripping that 50a breaker.

Please just plug it into a proper 120v outlet.

 

[Maticuno]

Sorry, misspoke on that one. It is a 20a circuit. The 50a is powering my stick welder.

 

[Davidad1]

That wiring diagram is for a 120 volt circuit . No 220 volt option is listed .


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[jmilch]

Agreed - there's no advantage to switching it to 240vac.

Agreed also. No need to worry about amperage from a 2 hp motor.