Cutting Off Appliance Attachment Plug

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infinity

infinity

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I recently saw a question in Electrical Contractor Magazine (bottom of page) and was surprised at the answer given.

http://www.ecmag.com/index.cfm?fa=article&articleID=9380

The question involved an appliance with a 15 amp attachment plug, a nameplate rating of 13.6 amps and a 15 amp branch circuit. The answer given said that the attachment plug must be removed and changed to a 20 amp on a 20 amp circuit. Since when does the NEC require us to rewire listed equipment?
 
That is one man's opinion that I do not share. I really don't see a microwave being used as a continuous duty appliance for 3 hours or more and if the appliance as delivered is UL rated then I do not agree with his decision.
 
ivsenroute said:
That is one man's opinion that I do not share. I really don't see a microwave being used as a continuous duty appliance for 3 hours or more and if the appliance as delivered is UL rated then I do not agree with his decision.
Click to expand...


I agree, I would use it as shipped.
 
I also do see a microwave as a continuous load, therefore a 15 amp rated attachment plug would be fine with a FLA rating of 13.6.

I would leave the cord alone.

Chris
 
infinity said:
I recently saw a question in Electrical Contractor Magazine (bottom of page) and was surprised at the answer given.

http://www.ecmag.com/index.cfm?fa=article&articleID=9380

The question involved an appliance with a 15 amp attachment plug, a nameplate rating of 13.6 amps and a 15 amp branch circuit. The answer given said that the attachment plug must be removed and changed to a 20 amp on a 20 amp circuit. Since when does the NEC require us to rewire listed equipment?
Click to expand...

"Branch circuit for microwave oven
Does the NEC permit a microwave oven to be supplied from a 15-ampere duplex receptacle protected by a 15-ampere branch circuit? The microwave oven has a nameplate load current of 13.6 amperes and is provided with a flexible cord and a 15-ampere, 125-volt attachment cap.
No, the cord and attachment cap (plug) must be changed to 20-amperes to comply with 210.21(B)(2) and Table 210.21(B)(2). This part of Section 210.21 limits the total cord-and-plug connected load on a 15-ampere receptacle to 12 amperes. Therefore, the 15-ampere cord and plug must be changed to 20-amperes, and the branch circuit must be 12 AWG copper, and the receptacle must have an ampere rating of 20-amperes."

I think he is 1/2 right. The truth as I read it is that this 13.6amp cord load exceeds the 12 amp "Maximum Cord-and-Plug-Connected Load
for outlet devices" on 15amp branch circuits. IT 210.21 (b) (2) doesn't specify continuous loads. SO IMO it has to be a 20amp circuit. I DON'T see that the plug has to be changed. This seems silly.
 
Twoskinsoneman said:
I think he is 1/2 right. The truth as I read it is that this 13.6amp cord load exceeds the 12 amp "Maximum Cord-and-Plug-Connected Load
for outlet devices" on 15amp branch circuits. IT 210.21 (b) (2) doesn't specify continuous loads. SO IMO it has to be a 20amp circuit. I DON'T see that the plug has to be changed. This seems silly.
Click to expand...

I agree with that.
 
Rather than do all that, just change the outlet to a single receptacle if it is a dedicated circuit and there is not a problem.

I see what he is trying to say but still don't agree since there was not enough information shared. There are too many variables.

If the branch circuit is dedicated to the microwave and has a single receptacle then nothing needs to be changed.
 
Why would the author think that changing the appliance?s cord cap would change the connected load? You would still have a 13+ amp load plugged into a 15 amp receptacle on a 15 amp branch circuit. :-?
 
charlie b said:
Why would the author think that changing the appliance?s cord cap would change the connected load? You would still have a 13+ amp load plugged into a 15 amp receptacle on a 15 amp branch circuit. :-?
Click to expand...

In his article he wants to change the branch feeder to 12awg copper and the receptacle to a 20A type.

All of this is a waste if you just make the receptacle a single type if the branch circuit is dedicated.

There is nothing wrong with a 13.6A load on a 15A circuit as long as it is not continuous.
 
need more input

need more input

i vote no on changing listed equipment. 2 - 20a SABC and micro, no problem, but what about 210.23A1. no one said mirco was in the kitchen.
 
ivsenroute said:
In his article he wants to change the branch feeder to 12awg copper and the receptacle to a 20A type.

All of this is a waste if you just make the receptacle a single type if the branch circuit is dedicated.

There is nothing wrong with a 13.6A load on a 15A circuit as long as it is not continuous.
Click to expand...

It is correct that 240.21(B)(2) limits the load on a 15 amp receptacle to 12 amps when a duplex receptacle is used.

As Ivsenroute pointed out a single 15 amp on an individual branch circuit receptacle will comply with 210.21(B)(1).
 
The argument is for naught. NO ONE runs a microwave for three hours contiuous. It falls in the same line of logic that you can actually use a #14 on an 49A OCPD (MOTOR extreme example) circuit.
 
Rockyd said:
The argument is for naught. NO ONE runs a microwave for three hours contiuous. It falls in the same line of logic that you can actually use a #14 on an 49A OCPD (MOTOR extreme example) circuit.
Click to expand...


Where in 210.21(B)(2) does it say continuous load?
 
ivsenroute said:
There is nothing wrong with a 13.6A load on a 15A circuit as long as it is not continuous.
Click to expand...
There is, if it is a plug & cord connected device, and if there is more than one 15 amp receptacle on a 15 amp circuit. And as Rob pointed out, it has nothing to do with the load being continuous.
 
Does the NEC permit a microwave oven to be supplied from a 15-ampere duplex receptacle protected by a 15-ampere branch circuit?
Click to expand...

no.......210.23(A)(1) shall not exceed 80%

one possible solution is put it on a 20A duplex, appropriately wired, while not the best, still a solution.
 
infinity said:
I recently saw a question in Electrical Contractor Magazine (bottom of page) and was surprised at the answer given.
Click to expand...

Really?
I wasn't surpised...not in the least.

I'm STILL waiting for a correction/retraction to be printed based on an error I found in Flach's article in ECMag back in 2007 ~ TYPO?


It seems every month that article has an error in it ~ I'm not surprised....and neither should any of you. :smile:
 
celtic said:
Really?
I wasn't surpised...not in the least.

I'm STILL waiting for a correction/retraction to be printed based on an error I found in Flach's article in ECMag back in 2007 ~ TYPO?


It seems every month that article has an error in it ~ I'm not surprised....and neither should any of you. :smile:
Click to expand...
How much do you want for that little space in the corner? Will you consider payments? Thanks.
 
celtic said:
Really?
I wasn't surpised...not in the least.

I'm STILL waiting for a correction/retraction to be printed based on an error I found in Flach's article in ECMag back in 2007 ~ TYPO?


It seems every month that article has an error in it ~ I'm not surprised....and neither should any of you. :smile:
Click to expand...


I find it kind of odd that in 2008 he doesn't include an e-mail address with his answers. I'm still waiting for a response from column in another trade magazine for over a year too. :rolleyes:
 
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