25A breaker on #12 Romex?

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  #1  
Old 10-21-20, 04:19 PM
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25A breaker on #12 Romex?

Can I use a 25A breaker on #12 wire in my workshop to power a 4.8hp jointer/Planer? The planer says that it runs at 16-17 amps depending on how big a cut you are making I guess. I told the rep for the equipment that I have a 20A 240V circuit. He said that I could get a 25A breaker for #12 wire and that would handle the load for starting up the machine, then the current draw would go down to 16 or 17amps.

Is this safe and allowed by code?

Otherwise can I add a 30amp circuit in my Utility room across the hallway and run a #10 extension cord when the jointer/planer is in use. This is a basement shop, not a commercial shop. And I only periodically use the jointer/planer. Normally the extension cord would be coiled and hung on the wall.

Thanks,
 
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Old 10-21-20, 04:32 PM
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If that is a dedicated circuit for your planer, then yes it is allowed.
 
  #3  
Old 10-21-20, 05:00 PM
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It’s a dedicated circuit for my table saw and would be for my planer as well. I only use the circuit for 220v tools in the shop.
Thank you!
 
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Old 10-21-20, 07:47 PM
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NO.... you are not to use a 25A breaker on #12 NM-b. NM-b is limited to 60C deg by code which is 20A.
 
  #5  
Old 10-21-20, 08:03 PM
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Because motors have starting current much higher than continuous running current, you are allowed to use larger sized breaker.

I think it was 250% of motor's FLC (full load current). I don't deal with motors often, so I'm not sure of exact code but I'm sure 25A breaker on 12AWG is fine as that is just a next size up. It might still trip the breaker if the motor starts with a load, but you shouldn't be starting jointer/planer with a load in the first place.
 
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Old 10-21-20, 08:07 PM
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That only applies to hardwired motor circuits.
See NEC 430.42(C)
 

Last edited by pattenp; 10-21-20 at 08:48 PM.
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Old 10-22-20, 07:19 AM
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Does the jointer have a manufacturer installed cord and plug? If so, what type plug is on it?
 
  #8  
Old 10-22-20, 07:37 AM
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If a 20A HACR breaker is slow enough, that becomes the best solution.
 
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  #9  
Old 10-22-20, 07:55 AM
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I’ll find out the question about the cord and plug. And ask about the. HACR breaker and if that would work. (I don’t know what that is, but I assume its a breaker with a delayed trip for startup).

The tool spec call for a 30A breaker.

If the tool runs on a 20A HACR is it dangerous to use it since it calls for a 30A? Or will I just run into it tripping the breaker?
 
  #10  
Old 10-22-20, 08:01 AM
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The tool spec call for a 30A breaker.
That's news. The cord/plug design will be telling. My experience is that compressors make a longer inrush surge. Things with low load/inertia, like saws and planers are not so inrush demanding of breakers.

 
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Old 10-22-20, 09:39 AM
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Most breakers that are newer are HACR. They have longer trip curve. If the jointer calls for 30A breaker then there may not be an installed cord and pllug.
 
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Old 10-22-20, 10:22 AM
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If the manufacturer calls for a 30 amp breaker then you need a 30 amp breaker and #10 cable.
 
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Old 10-23-20, 12:18 AM
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Learned from the manufacturer that the planer comes without any cord attached. Owner needs to install their own cord and plug. Does that change anything??
thank you.
 
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Old 10-23-20, 06:34 AM
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Doesn't change the fact that you need to follow manufacturer's instructions. If they say install on a 30 amp circuit, then by code you must install on 30 amp circuit.
 
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Old 10-23-20, 09:37 AM
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If the motor is truly rated at 4.8HP then it should be hardwired. Even a 50A nema 6-50 is only rated to 3HP.
 
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