motor-operated appliance?

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bphgravity

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How and when should an appliance be considered a motor-operated appliance and subject to the requirements of Article 430 verses it only being required to meet the requirements as a general pupose load under 422 or 210.23(A)?

For example, why are typical dishwashers and garabage disposals permitted to be supplied by 15A or 20A circuits and not by the requirements of 430. The same goes for compactors and garage door openers. 422.15(A) for central vacuum systems specifically references 210.23(A), yet none of the other listed appliances are specified in Article 422 for load considerations.

Also, I was recently looking at a new dryer at a retail store. The nameplate listed the appliance at 4,500-Watt, yet it came supplied with a 30A cord and the instructions specified a 30A branch circuit and receptacle. Why does a 18.75A load need a 30A circuit? How is this permitted?
 
Re: motor-operated appliance?

Brian the dryer question I can answer.
210.23(A)(1) limits us to a 80% load where a single circuit supplys a single appliance. and 18.75 amps plus the motor load and timer would exceed the 80% of a 20 amp circuit and be very close to going over a 25 amps circuit. so the next size up would be a 30 amp.
 
Re: motor-operated appliance?

Thnaks, but 422.10 doesn't really help. Thats where the question comes from.
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Brian,

I guess I'm missing your point about the code not being specific enough for the "appliance with motor(s)" circuit minimums. Maybe you could give us an example situation where you feel the code is vague?
 
Re: motor-operated appliance?

I started to post a reply to Bryan?s question yesterday, but then discovered that I had the same question myself. This is what confused me:
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  • <font size="2" face="Verdana, Helvetica, sans-serif">422.3 says that Article 430 shall apply to motor-operated appliances. But 422.10(A) says that Article 430 only applies to motor-operated appliances that do not have marked ratings.</font>
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I think, however, I found my answer in 422.62. The dryer (or dishwasher, as another example), falls into this article. The total load that the manufacturer is required to show as the nameplate rating must be calculated in accordance with 430.110(C)(1).
 
Re: motor-operated appliance?

I think, all of the items that you listed are subject to article 430, as stated in 422.3. But the manufacturer through the UL listing has already applied the applicable parts of 430 to the appliance and install a name plate indicating the requirements for installation (manufactures installation instructions)of course the disconnecting means is the cord and plug, and the motors are internally protected. Central vacuum,kitchen waste disposers, dishwashers and trash compactors are all listed in article 422.15 and 16. Then 422.20 states that "appliances employing methods of installation other than covered by this article shall be permitted to be used only by special permission". So the NEC has drawn the line! Not sure if that helped or not?
 
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