20 amp branch circuit

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Bowhunter

Member
Location
Illinois
I have a question that I give my class and it always causes much contriversy.

The question is : A cord and plug connected appliance drawing 16 amps is on a 20 amp branch circuit, adding a four amp receptacle load would be permissible.
True or false.

210.23 (A) (1) says the rating of any (one) cord and plug connected utilization equipment not fastened in place shall not exceed 80% of the branch circuit ampere rating.
Well it doesn"t.
210.23 (A) says a 15 or 20 amp branch circuit shall be permitted to supply lighting units or other utilization equipment, or a combination of both, and shall comply with 210.23 (A)(1) and (A((2).

So I feel the answer is true. Do you concur?
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I am not assuming anything. There is a statement to the effect that adding the specified load is permissable. Without knowing whether the appliance were fastened in place, I cannot assert that that statement is true. Therefore, I must give the answer "false."

To be specific,
  1. If the appliance is not fastened in place, then the statement is true. You have not yet violated the loading rules, and there is spare capacity for adding the four amp receptacle load.
  2. If the appliance is fastened in place, you already have a violation of 210.23(A)(2). Therefore, you cannot add any more load, but must instead correct the existing violation.
 

Little Bill

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Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I am not assuming anything. There is a statement to the effect that adding the specified load is permissable. Without knowing whether the appliance were fastened in place, I cannot assert that that statement is true. Therefore, I must give the answer "false."

To be specific,
  1. If the appliance is not fastened in place, then the statement is true. You have not yet violated the loading rules, and there is spare capacity for adding the four amp receptacle load.
  2. If the appliance is fastened in place, you already have a violation of 210.23(A)(2). Therefore, you cannot add any more load, but must instead correct the existing violation.

The question (IMHO) should have included "depends" in the answer choices. Whether you realize it or not you have assumed. You assumed that is was fastened in place or else you couldn't assert that it was "false." I don't think you could rightfully answer true or false without further information.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
The question (IMHO) should have included "depends" in the answer choices. Whether you realize it or not you have assumed. You assumed that is was fastened in place or else you couldn't assert that it was "false." I don't think you could rightfully answer true or false without further information.

That was my initial assessment.
 

iwire

Moderator
Staff member
Location
Massachusetts
From the OP

210.23 (A) (1) says the rating of any (one) cord and plug connected utilization equipment not fastened in place shall not exceed 80% of the branch circuit ampere rating.

I take this as the OP telling us that it is 'equipment not fastened in place'.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
And my suggestion to the OP is that he add that to the statement of the question, before he gives it to his students again.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I would agree, the question does not specify enough information to give a correct answer.
 

dpeter

Member
Location
Indianapolis, In.
Occupation
elevator mechanic / building maintenance
How does fastened in place or not change that it draws 16 amps? Doesn't it have to be continuos to preclude any additional load? Or does it?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
How does fastened in place or not change that it draws 16 amps? Doesn't it have to be continuos to preclude any additional load? Or does it?

If fastened in place the load on that unit is limited to 10 amps on a 20 amp circuit. If not fastened in place then a 16 amp load is permitted as well as additional receptacles.
 

dpeter

Member
Location
Indianapolis, In.
Occupation
elevator mechanic / building maintenance
Thank you for that Infinity.
As said before, it depends. When first looking at the question I assumed a code compliant start. Maybe a bit nieve(sp?) but that's the way I roll.
 

Bowhunter

Member
Location
Illinois
I would like to thank all you gentleman for your infinate wisdom.
I will change the first part of the question to a cord and plug connected appliance not fastened in place. That should leave no question as to the correct answer.
I will say it made for a great learning tool to promote duscusion about the two differant ways that appliances are addressed.

Thank You, Bowhunter:)
 
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