Thread: over fusing of electrical outlets

Recently, I have been calling out for safety and possible fire hazard, electrical outlets that are rated at 15 amps, where the main panel has 20 amp breakers. According to an electrical supply firm, I was told that ALL 20 amp outlets have a side ways "T" for the neutral wire. [With the cover off, the outlets are clearly marked with the amperage rating.] I do understand that a 20 amp outlet can be safely used with a 15 amp breaker.
Any thoughts on the do's and don'ts of this reporting?

Originally Posted by Stephen DeCosta

Recently, I have been calling out for safety and possible fire hazard, electrical outlets that are rated at 15 amps, where the main panel has 20 amp breakers. According to an electrical supply firm, I was told that ALL 20 amp outlets have a side ways "T" for the neutral wire. [With the cover off, the outlets are clearly marked with the amperage rating.] I do understand that a 20 amp outlet can be safely used with a 15 amp breaker.
Any thoughts on the do's and don'ts of this reporting?

15 amp receptacles are ok on 20 amp circuits (breaker and wire size) but 20 amp receptacle is not ok on a 15 amp circuit.

Originally Posted by Stephen DeCosta

Recently, .
Any thoughts on the do's and don'ts of this reporting?

In a nutshell I think you're wrong. I'm sure someone will post a code or something but as I remember it 15A receptacles are allowed on a 20A circuit with multiple receptacles - the theory being you won't use all the power through a single receptacle at once. The only time a receptacle must match the breaker is when it's a dedicated circuit to one receptacle.

I know I've seen hundreds if not thousands of houses over the years with 20A breakers and 15A receptacles.

Originally Posted by Vern Heiler

15 amp receptacles are ok on 20 amp circuits (breaker and wire size) but 20 amp receptacle is not ok on a 15 amp circuit.

Actually, 15 amp receptacles AND 20 amp receptacles (with the "T" slot) are perfectly okay on 15 amp breaker protected circuits with more than one receptacle (multioulet circuits).

Originally Posted by Jerry Peck

Actually, 15 amp receptacles AND 20 amp receptacles (with the "T" slot) are perfectly okay on 15 amp breaker protected circuits with more than one receptacle (multioulet circuits).

Excuse me. IMO you have that backwards.

Think aboiut it. A 20 amp appliance would have one flat prong. It can not be plugged in to a 15 amp receptacle, so there is no danger of a 20 amp load on that circuit.
If a 20 amp cicuit happens tp have 15 amp receptacles installed, there is no danger, just inconvenience for the owner of the 20 amp appliance, which I haven;t seen yet, but will soon.

• 

20 amp receptacles should not be installed on a 15 amp circuit.

A 20 amp device cannot be used on the 15 amp circuit according to the chart just posted.

On a side note, while I commend people trying to improve their knowledge, questions as basic as this make me wonder about the quality and depth of any of the training programs out there. IMO this information should have been covered before the first inspection was ever performed by someone holding themselves out as an HI.

Originally Posted by Jim Port

A 20 amp device cannot be used on the 15 amp circuit according to the chart just posted.

On a side note, while I commend people trying to improve their knowledge, questions as basic as this make me wonder about the quality and depth of any of the training programs out there. IMO this information should have been covered before the first inspection was ever performed by someone holding themselves out as an HI.

Jim, to come to the op's defense, think about how many times you have been in a class and the instructor got his/her reft and light mixed up! If there is not someone like me in the class (who questions everything and everybody) it goes down as gospel. Could be the case here.

There just seems to be a rash of questions like this popping up on the HI boards recently and it makes you wonder if there is that poor of a training resource available.

Originally Posted by Jim Port

There just seems to be a rash of questions like this popping up on the HI boards recently and it makes you wonder if there is that poor of a training resource available.

Which is why I believe there should be CE credits for being part of this board.

Originally Posted by Jerry Peck

Actually, 15 amp receptacles AND 20 amp receptacles (with the "T" slot) are perfectly okay on 15 amp breaker protected circuits with more than one receptacle (multioulet circuits).

Originally Posted by Brad Richter

Excuse me. IMO you have that backwards.

You are correct, I had that backwards. That is what I get for rushing to finish a post before heading out to inspections - me bad. Sorry.

Originally Posted by Jim Port

There just seems to be a rash of questions like this popping up on the HI boards recently and it makes you wonder if there is that poor of a training resource available.

I agree. And people are smart to, once explained the theory behind it they get it. I think extra training/material is a huge plus.

- - - Updated - - -

Anyway, a 20 amp circuit can have 15 amp outlets or 20 amp outlets, however it can not have a single 15 amp only and nothing else, it must be a 20 amp t slot. For example, a washer circuit which by code must be 12 gauge 20 amps can have a 15 amp duplex outlet, but if its a single plex like those for room A/C it must be a T slot.

A 15 amp circuit can have 15 amp devices but cant have T slots.

I still have a question of understanding the posts
If I have two 9.5 amp space heaters plugged into
a common dual electrical outlet that is rated for
15 amps. Then it will not trip the 20 amp breaker,
since the total amperage only 19 amps. Is that
what is being said as OK? Would not the 15 amp
breaker over heat?
What about reporting this situation to play it safe?

Even the 15 amp breaker may not trip due to the allowance in the trip curve for the breaker to handle 125% for 2 hours depending on the rate of rise.

A 15 amp receptacle is still rated for 20 amp feedthrough.

Originally Posted by Stephen DeCosta

I still have a question of understanding the posts
If I have two 9.5 amp space heaters plugged into
a common dual electrical outlet that is rated for
15 amps. Then it will not trip the 20 amp breaker,
since the total amperage only 19 amps.

Correct. That should not trip a 20 amp breaker.

Is that what is being said as OK?

No, a 20 amp circuit is only permitted to have 16 amps on it (not that there is any "Max Amperage Police" who will come looking for you if you do that).

Would not the 15 amp breaker over heat?

No, the 15 amp receptacle has 20 amp rated components in it (if I am saying it correctly, Jim Port will probably chime in and say it better ).

What about reporting this situation to play it safe?

Nope (regarding code and the 15 amp receptacle).

Yep (regarding the two heaters plugged into that receptacle on that 20 amp circuit as that is a potential hazard on the 20 amp circuit). It would be no different than finding those two heaters plugged into 20 amp rated receptacles on one 20 amp rated circuit - same potential hazard *for the circuit*.

Let's see if I did that better than this morning's post.

The 80% rating for breaker loads is only a factor for items that are considered continuous, which in code speak means 3 hours or more. Having a 19 amp load on a 20 amp breaker would not be an issue as the heaters will cycle.

Originally Posted by Jim Port

The 80% rating for breaker loads is only a factor for items that are considered continuous, which in code speak means 3 hours or more. Having a 19 amp load on a 20 amp breaker would not be an issue as the heaters will cycle.

You don't consider the heaters a continuous load?

Why would they be considered any differently than fixed space heaters or water heaters, both of which cycle off yet are considered continuous loads for branch circuit sizing?

The code wording could go either way, however (to me) it implies that the heaters could be considered to be continuous loads for branch circuit sizing.

Originally Posted by Stephen DeCosta

I still have a question of understanding the posts
If I have two 9.5 amp space heaters plugged into
a common dual electrical outlet that is rated for
15 amps. Then it will not trip the 20 amp breaker,
since the total amperage only 19 amps. Is that
what is being said as OK? Would not the 15 amp
breaker over heat?
What about reporting this situation to play it safe?

You are forgetting that a 15A duplex receptacle is TWO 15A receptacles on a single device yoke, with a 20A feed-thru rating.

Originally Posted by Stephen DeCosta

I still have a question of understanding the posts
If I have two 9.5 amp space heaters plugged into
a common dual electrical outlet that is rated for
15 amps. Then it will not trip the 20 amp breaker,
since the total amperage only 19 amps. Is that
what is being said as OK? Would not the 15 amp
breaker over heat?
What about reporting this situation to play it safe?

IMO it is not an inspector's job to report what ifs. Anyone could plug in three 1500 watt heaters on a 15 or a 20 amp circuit. You can't fix stupid.

This sometimes nothing more than a cost issue for the electrician and given the new requirements for receptacles is probably moot now.

Personally if I install a properly configured 20 amp branch circuit I would only place 20 amp receptacles on that circuit. Places 15 amp receptacles on a 20 amp circuit, while allowed in the code, introduces unnecessary confusion.

The 20 amp receptacle still serves as a connection point for a 15 amp device, but the circuit is visually easy to identify as a 20 amp circuit.

What is not allowed is to place a 20 amp receptacle on a 15 amp circuit. Again the reason obvious. That would allow the connection o a 20 amp device onto a 15 amp circuit.

Any way, just my personal opinion, for what that is worth.

Given the lack of appliances in a house with a 20 amp cord cap I see no need to waste money on installing a 20 amp T-slot device. The 20 amp device is not built any better.

Originally Posted by Stephen DeCosta

Recently, I have been calling out for safety and possible fire hazard, electrical outlets that are rated at 15 amps, where the main panel has 20 amp breakers. According to an electrical supply firm, I was told that ALL 20 amp outlets have a side ways "T" for the neutral wire. [With the cover off, the outlets are clearly marked with the amperage rating.] I do understand that a 20 amp outlet can be safely used with a 15 amp breaker.
Any thoughts on the do's and don'ts of this reporting?

WOOPS, You should not be calling that out as a safety hazard. Majority of receptacles in most homes are rated at 15 amps. They can be on either 15 or 20 amp circuits. As others have said, 20 amp receptacle's with T slots should be on a 20 amp circuit and nothing less.

Originally Posted by Donald Farrell

Personally if I install a properly configured 20 amp branch circuit I would only place 20 amp receptacles on that circuit. Places 15 amp receptacles on a 20 amp circuit, while allowed in the code, introduces unnecessary confusion.

I fully disagree.
This introduces NO "confusion" whatsoever. It is a typical installation, and has been for many decades.

Originally Posted by Donald Farrell

The 20 amp receptacle still serves as a connection point for a 15 amp device, but the circuit is visually easy to identify as a 20 amp circuit.

This I can agree with. The identification for a 20A circuit is a valid reason for using 20A receptacles.
Thing is, many people do not like to see those "weird" looking receptacle, and they are considerably more than 15A resi grade TR receptacle.
Having 20A receptacles for practical reasons is moot though. In all my years I have NEVER seen a portable residential appliance that had a 20A plug on it, with the exception of maybe an air conditioner or air compressor. Both of which would typically be on dedicated circuit anyway.

For quality reasons I only used "CR" spec-grade receptacles, regardless of the price, up until the nanny-state TR requirement came into my area. Now, spec-grade TR's are quite a bit more than either non-TR or resi-grade devices.
I do see a great improvement of plug retention over old non-TR resi receptacles so I am OK with using resi TR's now.

Originally Posted by Speedy Petey

I fully disagree.
This introduces NO "confusion" whatsoever. It is a typical installation, and has been for many decades. .

Speedy, the confusion I am referring to is visual identification. If I see a 20 amp receptacle, I know that it is on a amp circuit (or at least it should be) A 15 amp receptacle cab be on either a 15 or 20 amp circuit.

I don't now of many people who worry about how the receptacle looks, although I'm sure there are some. Most just comment that it looks different, strange, ugly, ect.