[hokiehawk79]

I have a bad GFCI outlet in my garage. How do I determine whether it is a 15amp or 20amp outlet. The bad outlet does not have a label that states the amps. The circuit breaker is 15. Does this mean I use a 15amp? Can I use a 20amp to replace it?

[ZoeMarie]

You would want to stay with a 15 amp outlet. If you want to change the whole circuit to 20 amps you could but that would be a lot more work than replacing the outlet you have with another 15 amp outlet.

[stanfortyman]

Most "standard" receptacles in a home are 15A. Unless you are in Canada there is NO reason to use 20A receptacles, even on a 20A circuit, unless a certain appliance or tool requires it.

[donf]

Opinion.

I prefer to use a receptacle that matches the circuit.

I like to know that the receptacle matches the breaker and conductors.

[ZoeMarie]

Personal opinion.

I prefer to use a receptacle that matches the circuit.

I like to know that the receptacle matches the breaker and conductors.

I had to spread the rep. but being consistent is the safest way to go!

[stanfortyman]

Personal opinion.

I prefer to use a receptacle that matches the circuit.

I like to know that the receptacle matches the breaker and conductors.

This is not really a valid point as ALL 15A receptacles are 20A feed-through.
The slots in the front are the ONLY difference.

[donf]

Stan,

The slots in the front are identifiers for the circuit behind it.

If you are looking at a standard 15 Amp receptacle, you expect a 15 Amp breaker upstream at the panel and therefore you know that the breaker is limited to a 12 amp load for the entire circuit.

If you are looking at a 20 receptacle, then your expectation is that there is a 20 amp breaker, 12 AWG conductors and you are limited to 16 amps for the total circuit.

Again it's just my opinion not dogma at all.

[stanfortyman]

I understand this is only your opinion, I am just trying to give you some clarification.

The slots in the front are identifiers for the circuit behind it.

If you are looking at a standard 15 Amp receptacle, you expect a 15 Amp breaker upstream at the panel and therefore you know that the breaker is limited to a 12 amp load for the entire circuit.

In the US this is absolutely NOT true. A 15A duplex can have either a 15 OR 20A circuit feeding it. In some homes all the general use receptacles are fed by 20A circuits.

With regard to 15 & 20 amp circuits the receptacle face is not nearly always an indication of circuit size.

You can certainly do it any way you like, but in most homes this is the case.

If you are looking at a 20 receptacle, then your expectation is that there is a 20 amp breaker, 12 AWG conductors and you are limited to 16 amps for the total circuit.

A 15A-240v circuit with a simplex receptacle will likely have a 15/20A rated receptacle. 210.21(B)(1)

Also, a 20A circuit is NOT "limited" to 16 amps. It is limited to 16 amps continuous. There is not much, other than lighting, that would be considered a continuous load in a residence.
Remember, a continuous load is something that is expected to remain on for 3 hours or more. Something being left on by accident does NOT constitute a continuous load.

A receptacle is limited to a certain load See the wording in 210.21(B)(2)

[Tev]

The answer to the original post is that you MUST use a 15A receptacle if you have a 15A circuit, which you do.

[tkrussell]

The first question:

How do I determine whether it is a 15amp or 20amp outlet.

Has not been answered.

I attached photos of a 15 amp and a 20 amp receptacle.

The one on the left with a Tee slot is the 20 amp.

The other with both blades parallel is the 15 amp, and the only one you should find since you have a 15 amp circuit breaker.

Do not use a 20 amp receptacle on a 15 amp circuit.