22o volt Air Compressor Wiring ?

[tspot100]

Hello.
Does anyone know if it is possible to attach a cloths dryer cord/plug onto a 220 volt air compressor so it can be plugged into the dryer outlet?
Strange, I know, but it would be much easier for me to just "plug in".
Thanks

[HayZee518]

The dryer cord is rated at 30 amps - what is the current draw of the compressor and is it three phase or single phase?

[tspot100]

220V aie compressor wiring

Thanks for the reply. The plate on the motor says:
Baldor
Volts- 115/240
HP- 2
Amps- 24/12
Cycle- 60
Single phase
I'll have to remove one of the compressors to read the rest. When I got it, one of the compressors was disconnected I think because it was running on 110 volts. I'd like to hook everything up and run 220v. It came with an inline switch/fuse box with 2, 30 amp glass household fuses. Is it possible to hook a 3 wire dryer cord to this?Thanks again.

[HayZee518]

Yes it is possible to hitch up to a dryer pigtail. the amp draw @ 240 is 12 amps. because it is a motor circuit use two fusetron time delay 20 amp screw in fuses. a motor when it starts draws 125% then nameplate current - so 12 times 1.25 = 15. the middle leg of the dryer pigtail would go to earth ground on the compressor controller, the two outer legs are your 220 hots.

[tspot100]

compressor wiring

Thanks again. I'll head to home despot and pick up some fusetron 20 amp fuses and give it a try tonite. I'll let you know if it blows....

[tspot100]

air compressor woes

I found the fuses and installed them. No go. It ran for 1 second then blew one of the 20 amp fusetrons. Anything I'm missing? Do I have to rewire the motor?

[HayZee518]

YES the motor needs to be re-configured for 240 volts. Essentially what you have is two separate windings each 120 volts. For 240 they are connected in series, for 120 in parallel. take off the motor cover and there should be a diagram inside. just follow the diagram.

[tspot100]

air compressor woes

Thanks again but I must be missing something.. I found the diagram and rewired the motor. One of the wires, #1, was not shown to be connected to anything, so I left it solo. Same as before, ran for a second then tripped. This time it blew the 30A cartridge fuse inside the sub box of the main panel. The other two inline fuses did not blow.
What am I missing?

[HayZee518]

Let me go to the baldor site and see if I can find a wiring diagram. Don't do anything more until I find out - ok?

[HayZee518]

I found some stuff on the motor - connections for 240 are: #1 to black hot, #4 & "S" to white, #2 & #3 & the other "S" together. To reverse direction, swap the two "S" leads. Ain't sure but I found the frame to be 145T - this motor they list as a TEFC [totally enclosed fan cooled]

[tspot100]

air compressor

thanks for the info. I drew a wiring diagram off of the motor but I still have questions.
What is the "S" wire you are referring to? Two of them. Only six wires come off the motor needing to connect to two (one balck and 1 white) wires. I'll try to post a pic. Thanks

[tspot100]

air compressor

I think I got it!!!
I went to the Baldor web site too. Heres the diagram they had. I hooked up as described and it ran! No fuses were blown. I'll now button it up and reconnect the 2nd compressor and hopefully it won't trip any fuses. Thanks for all your help.

[HayZee518]

I looked at your drawing from Baldor. You see how the coils (120 volt each) are connected for 240? Leads 1 & 2 form one winding, leads 3 & 4 form the other field winding. Those in the center are a thermal overload and the rest is the capacitor start with the centrifugal switch. If you were to connect them for 120 volts, both fields would be paralled. leads 1 & 3 together and 2 & 4 together, the start winding would also be connected to the paired leads. for reverse directions the start switch leads are reversed. Three phase machines for 240/480 are very similar only the field are wound for 240 as a base voltage. they are series connected for 480 or parallel for 240. the leads are nine or twelve leads for the windings. European motors have wierd voltages and use jumper straps for connections - i.e. 380 volts, 208 volts, 190 volts etc.