Common outlet over current protection.

Jeffrey L. Mathis · 10-21-2009, 05:49 AM

I was asked today if it was a code requirement that all outlets be wired with #12 and on a 20 amp breaker. That lighting could be #14 and 15 amp breaker. Maybe I should know the outlet part of the question, but I guess I do not.
Of one thing I am sure, the answer lies within this group.

thanks

JLMathis

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**Rick Cantrell** · 10-21-2009, 06:09 AM

When you say "outlets" I presume you to mean, "Receptacle outlets".

"... if it was a code requirement that all outlets be wired with #12..."
No, most outlets are allowed to be wired with #14 wire on a 15 amp breaker. But most outlets are wired with #12 wire and on a 20 amp breaker.

"... and on a 20 amp breaker."
Most outlets are allowed to be on a 15 amp breaker

" That lighting could be #14 and 15 amp breaker."
Lighting circuits are also allowed to be on a 20 amp breaker with #12 wire.
But most are #14 wire with a 15amp breaker.

" Maybe I should know the outlet part of the question, but I guess I do not."
Thats what this forum is for.

**Jim Port** · 10-21-2009, 06:20 AM

To expand on Rick's answer. If it is on a 20 amp breaker a receptacle or lighting circuit must use #12.

With few exceptions like bathroom receptacles, small appliance countertop circuits required for the kitchen and the laundry receptacle there is no requirement for a 20 amp circuit, unless called for by the nameplate.

**Bruce Ramsey** · 10-21-2009, 06:22 AM

"I was asked today if it was a code requirement that all outlets be wired with #12 and on a 20 amp breaker."

If the circuit is protected by a 20 amp breaker, then #12 wire is required. Two 20 amp circuits are required in kitchen for receptacles.

"That lighting could be #14 and 15 amp breaker."

If a circuit is protected by a 15 amp breaker, #14 wire is adequate. #12 wire can be used in place of #14 if desired. Lighting circuits are commonly 15 amp but can be 20 amp.

The size of the breaker determines the minimum size of the wire to be used. Conversely if the wiring is already run, then it determines the maximum size breaker that can protect the circuit.

**Gunnar Alquist** · 10-21-2009, 07:00 AM

I believe that you will find that most receptacle outlets are rated for 15 amps. They do make 20 amp versions, but these are generally not used in most residential applications.

**Jim Port** · 10-21-2009, 08:19 AM

The number of appliances with a 20 amp cord cap in a residential settingis typically 0. Therefore no need for the 20 amp configuration in receptacles. Commercial and industrial is different.

A 15 amp duplex is still good for 20 amp feed-thru current.

**John Kogel** · 10-21-2009, 10:13 AM

Originally Posted by Jim Port

The number of appliances with a 20 amp cord cap in a residential settingis typically 0. Therefore no need for the 20 amp configuration in receptacles. Commercial and industrial is different.

A 15 amp duplex is still good for 20 amp feed-thru current.

Jim, I think you're saying that we can have duplex receptacles rated for 15 amps installed on a 20 amp circuit, because the appliances which could be plugged in will not draw more than 15 amps each? Is that what you're saying?

**Jim Port** · 10-21-2009, 11:28 AM

John K,

In the US if there is more than 1 place to plug into the circuit, you can have 15 amp slot devices on the circuit. A duplex counts as 2 places.

A simplex receptacle would need to be rated for the OCPD.

**Jerry Peck** · 10-21-2009, 01:19 PM

Jeffery,

20 amp rated circuits are only required for some receptacle outlet locations, as Jim Port said (bathroom, kitchen small appliance, laundry, and the like), leaving all other receptacle outlets being on 15 amp rated circuits.

Keep in mind that "outlets" means lighting outlets, smoke detector outlets, and receptacle outlets, so you need to define what you are asking by specifying "receptacle outlets".

As stated in posts above, as long as there are two more more "receptacle outlets" on a circuit, each receptacle outlet on a 20 amp circuit is allowed to be rated for 15 amps.

When there is only one receptacle outlet on one circuit, then the receptacle outlet needs to be rated for at least as much as the circuit is rated. This may seem odd, in that you are allowed to install a single 50 amp receptacle on a 30 amp circuit as the only receptacle outlet but are not allowed to install a single 30 amp receptacle on a 50 amp circuit as the only receptacle outlet.

You may be thinking 'But, if you plug in a 50 amp appliance the breaker will trip.', which is in fact true, and good.

The other option would allow a 30 amp appliance to be plugged into a 50 amp circuit on a 50 amp breaker, allowing the receptacle to burn up before the breaker trips. This would not be good.

Jeffrey L. Mathis · 10-21-2009, 02:39 PM

Thanks to all. And yes I meant receptacle outlets. It does all start with good language. I understand the wire size/breaker size relationship just fine. And I look religiously for that. But when my buddy said "Don't all receptalce outlets have to be on a 20 amp breaker?"
I did not have a clear answer.

JLMathis