Purpose of 20 amp receptacles

[infinity]

Funny, I'm just thinking back several years ago when a supply house told me that they were considering stocking only 20A duplex receptacles instead of both 15A and 20A. My thought at the time was "you can install 15A duplex receptacles on a 20A circuit but would it be correct to install 20A duplex receptacles on a 15A circuit?"

No, you cannot install a 20 amp duplex on a 15 amp circuit.

 

[jumper]

No, you cannot install a 20 amp duplex on a 15 amp circuit.

But you could put a single 20A receptacle on a 15A circuit.

Never totally understood the logic behind the difference myself.

 

[JFletcher]

I install all 20A in my own house. Don't think I have ever plugged in a 20 A plug upstairs.

Main reason for using 20A is that the edge contact does a better job over time maintaining contact pressure.

Ive replacde 100's of 15 A duplex outlets due to no plug retention remaining, only ever replaced 1 20 A due to low retention force (and that one is the one DW used a few times a week for 40 years for the vacuum cleaner)

Sounds like you are using commercial or spec grade receptacles vs standard ones. and the ones you replaced were standard grade, probably the cheapest thing the contractor could use for the job. I've replaced quite a few of them myself.

I know they are what most sparkys spec for big budget commercial jobs but how many go with the horizontal tab never used in their entire lives? Sort of a waste IMO and I see them all the time. I am sick of them unless there is an AC window unit don’t bother me with installing these things. If you are putting these on a job you are wasting your clients money

I'm looking at several in a hotel room as I type. The window PTAC is a 6-20R.

 

[jeff48356]

But you could put a single 20A receptacle on a 15A circuit.

I don't think that's allowed either. When a single receptacle is used on a dedicated circuit, the amperages of the breaker and receptacle need to match.

 

[jumper]

I don't think that's allowed either. When a single receptacle is used on a dedicated circuit, the amperages of the breaker and receptacle need to match.

Nope.

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.

 

[MAC702]

...When a single receptacle is used on a dedicated circuit, the amperages of the breaker and receptacle need to match.

It is quite common for welding machine receptacles to all have a NEMA 6-50 device, even though some may only be a 30A circuit.

As jumper cited, this is fine.

 

[zbang]

If equipment requires a 20A plug then it needs it's own circuit, so a 20A duplex is useless in most cases.

How's that? I've seen plenty of equipment which comes with a 20A plug but doesn't draw near that.

(I have a 2200VA UPS at home; came with a 5-20p and is happily sharing the circuit with a couple of lamps and the computer monitors. It's also only loaded to about 8-900VA.)

 

[infinity]

I don't think that's allowed either. When a single receptacle is used on a dedicated circuit, the amperage's of the breaker and receptacle need to match.

Many range circuits are 40 amps but there is no 120/240 volt, 40 amp receptacle so a single 50 amp is used and is code complaint.

 

[goldstar]

No, you cannot install a 20 amp duplex on a 15 amp circuit.

That was the point I was trying to make to the supply house - it just didn't come out the way I intended.

 

[MAC702]

Since 210.21(B) allows the 20A receptacle on the 15A circuit, what section would prohibit it?

 

[ActionDave]

Since 210.21(B) allows the 20A receptacle on the 15A circuit, what section would prohibit it?

That allows a single receptacle on smaller breaker, not a duplex.

 

[MAC702]

That allows a single receptacle on smaller breaker, not a duplex.

Ahhhh, "receptacle" as opposed to "receptacle outlet." Got it.