30 amp breaker

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  #1  
Old 05-01-11, 05:06 AM
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30 amp breaker

I have an old air compressor that is required to be plugged into a 30 amp circuit. I'm thinking of using 10/2 cable, or 10 gauge wire for it, I have the 30 amp, single pole breaker, but can't seem to find a 30 amp outlet at the local hardware store, plenty of 15 and 20 amp outlets, just can't find a 30 amp, I asked about it and they looked at me like I was goofy. Are there 30 amp duplex outlets availiable ? Is this the way this should be done ? Thank you !
 
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Old 05-01-11, 06:17 AM
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Are there 30 amp duplex outlets availiable
No. You need a simplex receptacle NEMA type 5-30R. If you don't have a 5-30P plug on your compressor you should change it out.

 

Last edited by ray2047; 05-01-11 at 06:34 AM.
  #3  
Old 05-01-11, 07:33 AM
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Are you sure the A/C is 120 volts?
 
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Old 05-01-11, 08:17 AM
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The end of the original cord is just a regular 2 prong, with a ground, 3 prong if you look at it counting all prongs, ground included, the kind you would find on any regular household appliance. It's 110 volt, no I'm not reading it wrong, that's exactly what it say's on the original sticker ! It also say's on the same sticker that it requires a 30 amp fuse or breaker. It works fine when I plug it into a string of outlets I ran with 12/2 cable and 20 amp outlet recepticles, nothing gets hot at all, So, should I change the wire from the motor and put a plug on it like you sent me the picture of, or what ?
 
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Old 05-01-11, 09:38 AM
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You don't mention the rated running current, but with a HACR 20a breaker, you may be OK, as long as the running current is 15 amps or less.
 
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Old 05-01-11, 02:59 PM
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Ok, there is a metal tag on the motor that says, V. 115, on one line, then, 17.8 F.L.A. on the next line. What does this mean, Voltage 115, Field Line Amperage ? It also says 40 amps max, thermally protected, on the same tag. There is another spot on the tag that says 230 Volts, 8.9 amps.
 
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Old 05-01-11, 04:52 PM
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FLA= Full Load Amps = Amps during normal running. The amp draw can be up to three times that during startup.

If available, I suggest wiring the motor for 240 volts and running it on a 20 amp circuit. Or if you have already ran the #10 wire, you could run it on a two pole 30 amp breaker, but I would be betting a 20 will be fine.
 
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Old 05-01-11, 05:21 PM
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Ok, how would I go about wiring the motor for 240 ? If I did this, would I need to change the plug to what "ray2047" suggested below, or what kind of plug, outlet, and cable, or wire should I run after I've wired the motor for 240 volts ?
 
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Old 05-01-11, 06:35 PM
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If you switch it to 240, you use a nema 6 or 14, not using the neutral in the male plug cap. Nema 6-20 seems the best for this application, two hots and a ground.
 
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Old 05-01-11, 07:31 PM
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Ok, how would I go about wiring the motor for 240
The wiring diagram should be on the name plate.

would I need to change the plug to what "ray2047" suggested below,
No. My suggestion was if the motor was run on 120v. You would need a 240v plug and receptacle. Since the 240v FLA is 8.9 you may be acle to use a 15 amp breaker and a NEMA 6-15 receptacle plug but going with a NEMA 6-20 as suggested by Justin gives more breathing room for starting.
 
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Old 05-01-11, 07:34 PM
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Originally Posted by gearhead59 View Post
Ok, how would I go about wiring the motor for 240 ? ?
The wiring diagram might also be on the inside cover where the wires go into the motor.
 
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Old 05-01-11, 09:06 PM
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Since the 240v FLA is 8.9 you may be acle to use a 15 amp breaker and a NEMA 6-15 receptacle plug but going with a NEMA 6-20 as suggested by Justin gives more breathing room for starting.
I remember at my old house, every time the 12A a/c kicked on, it tripped the 15A breaker if something else was on, even if it drew less than 3A. Sometimes it tripped even if nothing else was on. Figured I'd mention that.
 
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Old 05-02-11, 04:25 AM
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Thanks for the help guys ! I will get a newer air compressor someday, but this one is going to have to do for now, and thanks to you guys, I'll be able to use it safely now !
 
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