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NEC Table 210.24 allows a 15 amp receptacle to be installed on a 20 amp circuit. How is this ok?
For one, the appliance that you use on the circuit has a plug on it that is rated in amps. Why would a manufacturer put a 15 amp plug on an appliance that draws 18 amps?

Another thing is, a 15 amp receptacle is rated for 20 amp feedthrough, so that the portion of the circuit downstream from a receptacle can still deliver 20 amps.

In other words, the code is relying on the idea that appliances with 15 amp plugs won't use over 15 amps in the application it was intended for.
 

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NEC Table 210.24 allows a 15 amp receptacle to be installed on a 20 amp circuit. How is this ok?
Because the 15A receptacle is engineered to take// pass// tolerate 20A anyway.

The only NEMA difference between them is pattern -- the plastic opening and the conductor body underneath.

The NEC is oriented towards safety... not 'logical purity.' ( however defined )

&&&

You can trudge through old threads here at ET.

And find this issue utterly beaten to death. :rolleyes:
 

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in the cec you cant, with a power strip you can easliy put 20 amp of load on a 15 amp receptacle
The guts of a 15 and 20 amp receptacle are the same . The difference is the slot on the 20 amp receptacle.

Remember if this is a single receptacle being fed from an individual 20 amp circuit then the single receptacle must be 20 amp.

210.21 (B) Receptacles.
(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.
 

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The guts of a 15 and 20 amp receptacle are the same . The difference is the slot on the 20 amp receptacle..
How do you know they are the same? Are you sure there is not just a tad more contact area on a 20? It seems like you and telsa are assuming something that you do not have substantiation for. I have never held a 20 molded plug that did not have a pretty hefty feel.
 

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How do you know they are the same? Are you sure there is not just a tad more contact area on a 20? It seems like you and telsa are assuming something that you do not have substantiation for. I have never held a 20 molded plug that did not have a pretty hefty feel.
I have been told by members at mike holt who have talked with the manufacturers. I believe Don can verify this but I have no first hand knowledge.
 
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It has to be remembered, a 15A duplex is constantly called a "15A device". Thing is, it is TWO 15A receptacles on a common yoke.
 

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Am I missing something? You can't use a recep. to "feed through" you must pigtail the conductors, especially the neuts.
The only code requirement for pigtail is the neutral of a multiwire branch circuit.

I, and others have taken 15 and 20 amp receptacle of the same brand and series apart...the guts are identical. It is just function of manufacturing efficiency....it is easier and more cost effective to make the guts of the two identical. Some manufacture reps have said the same thing.
 

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20 amp Duplex Receptacles

The reason the manufacturers do not have back stab connections for #12 solid is that when Aluminum wire was used the smallest size is #12 for 15 amp circuits. to prevent Aluminum connections they only use screw terminals and now COALR type for Aluminum. By using pig tails it puts less stress on the screw terminals that could loosen the screws.
 

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The reason the manufacturers do not have back stab connections for #12 solid is that when Aluminum wire was used the smallest size is #12 for 15 amp circuits. to prevent Aluminum connections they only use screw terminals and now COALR type for Aluminum. By using pig tails it puts less stress on the screw terminals that could loosen the screws.
The change in the UL standard to prohibit the use of back stab connections for #12 came long after aluminum was off the market in the #10 and #12 sizes. Aluminum conductors in those sizes have been off the market since the mid 70s. I believe the standard was changed to prohibit back stabbed #12 in the late 80s.

It was based on connection failures with the #!2, one of the reason being the additional stiffness of the #12 when you put the receptacle in to the box put pressure on the connection that reduced its current carrying capacity.
 

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Am I missing something? You can't use a recep. to "feed through" you must pigtail the conductors, especially the neuts.
Says who? Spec? Local tradition? Co- workers? Like Don said, multiwire branch circuit neutrals only per NEC.
 
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