210.21 b 1

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splinetto

Senior Member
Location
Missouri
I was looking at 210.21 b 1 and was wondering if the 15A GFCI I put next to the panel on a 20A ckt is OK. It says single recep, So does it mean a 1 hole recep has to rated the same as the ckt or am I Ok? After reading the def I have the answer ..Unless I missed something I'm looking at the 99 NEC.
 

480sparky

Senior Member
Location
Iowegia
I've never seen a single GFI receptacle. (But there's a lot I haven't seen....)
If you have a 15-a rated duplex on a 20a circuit, it's legal.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
210.21(B)(1) is for single receptacle circuits. A duplex is two receptacles. You could put a 20 amp single receptacle on a 15 amp circuit but you cannot put a 15 amp single receptacle on a 20 amp circuit.
 

stickboy1375

Senior Member
Location
Litchfield, CT
infinity said:
210.21(B)(1) is for single receptacle circuits. A duplex is two receptacles. You could put a 20 amp single receptacle on a 15 amp circuit but you cannot put a 15 amp single receptacle on a 20 amp circuit.

Don't forget that the branch circuit has to be a "individual branch circuit"
 

480sparky

Senior Member
Location
Iowegia
infinity said:
210.21(B)(1) is for single receptacle circuits. A duplex is two receptacles. You could put a 20 amp single receptacle on a 15 amp circuit but you cannot put a 15 amp single receptacle on a 20 amp circuit.

You cannot put a 20amp recep on a 15amp circuit.
 

peter d

Senior Member
Location
New England
480sparky said:
You cannot put a 20amp recep on a 15amp circuit.

The actual wording of the code allows a single 20 amp receptacle on an individual (dedicated) 15 amp circuit.

Think about this one too. How many times have we installed a 50 amp range receptacle using 8/3 Nm cable and a 40 amp breaker? It's not a violation.
 

dana1028

Senior Member
peter d said:
The actual wording of the code allows a single 20 amp receptacle on an individual (dedicated) 15 amp circuit.

Think about this one too. How many times have we installed a 50 amp range receptacle using 8/3 Nm cable and a 40 amp breaker? It's not a violation.

Would you be kind enough to provide that 'actual wording' please [and of course the corresponding code section]; I can't find it.

I did find Table 210.21(B)(3) which indicates a receptacle rating of "not over 15 amperes" permitted on a 15A circuit; that same table does allow a 50A receptacle on a 40A circuit.
 

peter d

Senior Member
Location
New England
dana1028 said:
Would you be kind enough to provide that 'actual wording' please [and of course the corresponding code section]; I can't find it.

Sure. Simply read the wording of 210.21(B)(1). The only requirement is that the rating of the receptacle be "not less than" that of the branch circuit. There is nothing forbidding the receptacle to be rated more than the rating of the branch circuit.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
480sparky said:
I've never seen a single GFI receptacle. (But there's a lot I haven't seen....)
If you have a 15-a rated duplex on a 20a circuit, it's legal.

maybe now you have:grin:
Gfiwithswitch.jpg
 

raider1

Senior Member
Staff member
Location
Logan, Utah
I agree with Peter,

A single receptacle installed on a individual branch circuit shall have a rating not less then the rating of the branch circuit.

I did find Table 210.21(B)(3) which indicates a receptacle rating of "not over 15 amperes" permitted on a 15A circuit; that same table does allow a 50A receptacle on a 40A circuit.

210.21(B)(3) if for branch circuits supplying two or more receptacles or outlets.

Chris
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
raider1 said:
210.21(B)(3) if for branch circuits supplying two or more receptacles or outlets.
Chris

Dana-- Chris' statement comes from art. 210.21(B)(3). It states exactly what he is saying and reference the Table in discussion.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
210.21(B)(1) Single Receptacle on an Individual Branch Circuit A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.
 

inspector23

Senior Member
Location
Temecula, CA
don_resqcapt19 said:
210.21(B)(1) Single Receptacle on an Individual Branch Circuit A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.


So you are saying you could put a 50 amp single receptacle on a 15 amp branch circuit?????Yes, 210.21 (B) (1) does state it is possible. BUT it is only one section of Part II, Branch circuit ratings.

Another section of that same part (Part II, branch circuit ratings), section 210.23, states that in no case shall the load exceed the branch-circuit ampere rating.

By installing that 20 amp receptacle, you would be allowing for a potential of a 20 amp load on a 15 amp individual branch circuit, a clear violation of 210.23.

So, in theory, if you just look at section 210.21 (B) (1), you could put the 20 amp receptacle on the 15 amp circuit. But when you review the entire part of article 210, you can easily see where this would be a violation if installed.

You have to take the sections in the context of the entire Parts of the articles.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Another section of that same part (Part II, branch circuit ratings), section 210.23, states that in no case shall the load exceed the branch-circuit ampere rating.

Don't you think that is the purpose of the OCP. If you have a 40 amp receptacle on a 20 amp breaker the only issue would be the breaker tripping not the receptacle failing.
 

raider1

Senior Member
Staff member
Location
Logan, Utah
The purpose of 210.21(B)(1) is to make sure that the receptacle is rated no less then the branch circuit. A 20 amp single receptacle can be installed on an individual 15 amp branch circuit. Dennis is correct that the OCP will limit the load on the circuit.

Chris
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
raider1 said:
The purpose of 210.21(B)(1) is to make sure that the receptacle is rated no less then the branch circuit. A 20 amp single receptacle can be installed on an individual 15 amp branch circuit. Dennis is correct that the OCP will limit the load on the circuit.

Chris


Agreed, "what if's" don't really matter since the circuit is protected by the OCPD ahead of it.
 

iwire

Moderator
Staff member
Location
Massachusetts
inspector23 said:
So you are saying you could put a 50 amp single receptacle on a 15 amp branch circuit?????

Yes, you could do just that, it is not unsafe.

Keep in mind that the NEC is interested in safety not convenience.

Take a look at 90.1(A) and 90.1(B).
 
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