That's true whenever there is only one outlet on the branch circuit.
Is a duplex receptacle one outlet or two?
Back when I sold receptacles, I had one contractor that would buy a cheap residential brand because its face looked like the more expensive spec'd style. I would not put it past him to use the <$1 ones if 15A were allowed.
I agree that some contractors will cut that corner if they can get away with it. As with anything that is part of a specification someone needs to check for compliance.
Two receptacles in one outlet. Two for this discussion.
So are you saying that (1) 15a duplex can be put on a 20a circuit?
That is correct.
Yes if there is more than one receptacle on a 20 amp each receptacle can be 15 amps. One 15 amp duplex would be permitted to be the only receptacles on the 20 amps circuit.
Yeppers. This must match the circuit:
I would say that it doesn't need to match the circuit OCPD it needs to be equal or greater than the OCPD/circuit size. The 20 amp single device in the photo is permitted on a 15 amp circuit.
I was always taught that because a duplex receptacle is under one yoke that it is considered one device and one 15A duplex cannot be put on a 20 amp circuit.
That is incorrect. A duplex is two receptacles even if they're on a single yoke.
And to further show this is the case the tabs can be broken on both sides and the two receptacles can be fed with two circuits.
