[Wayner]

Lee,

Glad you found the appropriate section of the NEC. I have it at work..or did have it but it (as usual) found legs and walked away. The point is that the circuit breaker (or fuse) controls the ampacity of the outlet in this case.

You can put a 1 amp breaker on a 20 amp outlet and if you hit 125% of the rating...pop!

People, just use your head and alway replace with same rated devices, or get an electrician to do it.

Wayner

[cryoparts]

Great advice there!   aa

Peace,

Lee

or get an electrician to do it.

[mjosef]

FYI--While I neither endorse or recommend that a person installs a 20A receptacle on a 15A circuit, it is done all of the time by audiophiles.

Lee

  Audiophiles have been known to defy laws and codes.

[cryoparts]

Nah...really?   

Lee

FYI--While I neither endorse or recommend that a person installs a 20A receptacle on a 15A circuit, it is done all of the time by audiophiles.

Lee

  Audiophiles have been known to defy laws and codes.

[yooper]

Damn!    I picked up a couple 20a outlets from Lowes today, but am now worried about installing these things on 15a circuits!!!

It seems as long as you only plug 15a plugs into them you would be fine, but I also read that if you have a house fire for any reason, and the fire inspector notices 20a outlets where 15a belong........ no coverage... that would be bad.

Looks like I may just hold off on the tweak and get the 15a outlet.

Mark

[ctviggen]

Damn!    I picked up a couple 20a outlets from Lowes today, but am now worried about installing these things on 15a circuits!!!

It seems as long as you only plug 15a plugs into them you would be fine, but I also read that if you have a house fire for any reason, and the fire inspector notices 20a outlets where 15a belong........ no coverage... that would be bad.

And where did you read that?  Unless they can point to that as being the cause, there should be no way they could deny coverage for that.

[zybar]

Damn!    I picked up a couple 20a outlets from Lowes today, but am now worried about installing these things on 15a circuits!!!

It seems as long as you only plug 15a plugs into them you would be fine, but I also read that if you have a house fire for any reason, and the fire inspector notices 20a outlets where 15a belong........ no coverage... that would be bad.

Looks like I may just hold off on the tweak and get the 15a outlet.

Mark

I don't see how having a 20 amp outlet on a 15 amp line would cause any type of safety or insurance issue.

Now a 15 amp outlet on a 20 amp line is a different kettle of fish...

George

[cryoparts]

It is.  It's an NEC thing.  A few posts back I posted a link to the actual code document. 

A 20A receptacle on a 15A line (which is determined by the breaker and wire size) is a violation of code.  A 15A receptacle on a 20A line is fine.

Here's a good discussion:

http://forums.mikeholt.com/archive/index.php/t-75966.html

Peace,

Lee

Damn!    I picked up a couple 20a outlets from Lowes today, but am now worried about installing these things on 15a circuits!!!

It seems as long as you only plug 15a plugs into them you would be fine, but I also read that if you have a house fire for any reason, and the fire inspector notices 20a outlets where 15a belong........ no coverage... that would be bad.

Looks like I may just hold off on the tweak and get the 15a outlet.

Mark

I don't see how have a 20 amp outlet on a 15 amp line would cause any type of safety or insurance issue.

Now a 15 amp outlet on a 20 amp line is a different kettle of fish...

George

[yooper]

And where did you read that?  Unless they can point to that as being the cause, there should be no way they could deny coverage for that.

I spent some time googling and ran across a few snippets on forums mentioning the insurance thing.  Granted, the information can certainly be incorrect and more than likely, I'm thinking to much about nothing.  

But I agree, coverage should not be an issue.  Unless the fire was intentional and proven as such, there should be no denial of coverage.   But I don't know for sure and if I can't be 100% certain, it just seems less problematic to use the 15a hospital grade instead.

I certainly didn't mean to change the topic of this thread... don't mind me..... carry on.

Mark

[Wayner]

According to table 210.21(B)(3) of the NEC code, a 15A branch circuit can only have a 15A receptacle attached.  A 20A branch circuit can have either a 15A or a 20A receptacle attached.

I don't see how have a 20 amp outlet on a 15 amp line would cause any type of safety or insurance issue.

Now a 15 amp outlet on a 20 amp line is a different kettle of fish...

George

Lee and George have hit the nail on the head and some of you are not listening.

To keep it simple, lets forget about the wire gauge for this discussion.

If you have a 20 amp breaker, you can use a 15 or 20 amp receptacle.

If you install a 15 amp outlet on a 20 amp breaker, you have under-protected the outlet by 5 amps. Besides being illegal, if you plug a device capable of more than 15 amps of current draw, the ampacity of the 15 amp outlet will be breached and melt down will start to occur in the outlet because the 20 amp breaker will not trip. Then you will have fire. Very bad.

1. To play it safe, always replace outlet with same amperage rating as circuit breaker.
2. Never change out a 15 amp breaker with a 20 amp breaker (unless you change the wire gauge).
3. Install wires according to instructions that came with the outlet.
4. Better yet, have an electrician do it.

This is the best advice I can give.

Wayner

[Wayner]

George,

de-rating a 20 amp outlet with a 15 amp breaker is OK in my books and in the industrial setting, de-rating happens all the time. Yesterday I fused some 15 amp receptacles with 6 amp fuses because we didn't want that high of an over-load to trip point. Again, this is in an industrial setting!

In residential wiring, I can understand why the NEC doesn't like this because it allows an over rated device to be plugged into the outlet. Of course, if the current goes over 15 amps, the breaker will trip, but the door mat says "20 amps welcome", when it's not.

How's that for a bad explination?

Wayner

[cryoparts]

To keep it simple, lets forget about the wire gauge for this discussion.

If you have a 20 amp breaker, you can use a 15 or 20 amp receptacle.

Yes!

If you install a 15 amp outlet on a 20 amp breaker, you have under-protected the outlet by 5 amps. Besides being illegal, if you plug a device capable of more than 15 amps of current draw, the ampacity of the 15 amp outlet will be breached and melt down will start to occur in the outlet because the 20 amp breaker will not trip. Then you will have fire. Very bad.

Yes!  For anyone that needs a reference, please check table 210.21(B)(3) of the NEC code, a 15A branch circuit can only have a 15A receptacle attached.  A 20A branch circuit can have either a 15A or a 20A receptacle attached.

The danger is that a 20A device could be plugged into a 15A circuit, the breaker fail and not trip, and start a fire.

A 15A device plugged into a 20A circuit can draw 15A all day long and all will be well.    A 20A device plugged into a 15A circuit would be bad, in the event the breaker did not trip.   

FYI--most commercially made receptacles 15A and 20A receptacles have the same guts, just different face plates. 

1. To play it safe, always replace outlet with same amperage rating as circuit breaker.
2. Never change out a 15 amp breaker with a 20 amp breaker (unless you change the wire gauge).
3. Install wires according to instructions that came with the outlet.
4. Better yet, have an electrician do it.

Yes!  #4 is fantastic advice, thank you Wayne!

I don't want to keep beating a dead horse here, but, I want to make sure the correct information is relayed.

All of this being said, 20A receptacles are installed all the time on 15A circuits by audiophiles.  Just be aware, it does not meet code.  That's all I wanted to get across.

Peace,

Lee

[cryoparts]

In residential wiring, I can understand why the NEC doesn't like this because it allows an over rated device to be plugged into the outlet. Of course, if the current goes over 15 amps, the breaker will trip, but the door mat says "20 amps welcome", when it's not.

Exactly.  The fear of the NEC is that the breaker will fail and a fire will somehow start.

Lee

[Wayner]

Lee,

re-read my post. We're saying the same thing.

If you install a 15 amp outlet on a 20 amp breaker, you have under-protected the outlet by 5 amps. Besides being illegal, if you plug a device capable of more than 15 amps of current draw, the ampacity of the 15 amp outlet will be breached and melt down will start to occur in the outlet because the 20 amp breaker will not trip. Then you will have fire. Very bad.


No.  Please check table 210.21(B)(3) of the NEC code, a 15A branch circuit can only have a 15A receptacle attached.  A 20A branch circuit can have either a 15A or a 20A receptacle attached.

The danger is that a 20A device could be plugged into a 15A circuit, the breaker fail and not trip, and start a fire.

A 15A device plugged into a 20A circuit can draw 15A all day long and all will be well.    A 20A device plugged into a 15A circuit would be bad, in the event the breaker did not trip.   

FYI--most commercially made receptacles 15A and 20A receptacles have the same guts, just different face plates

[cryoparts]

Duh. We sure are.  Ha!     I'll go do some editing.

I'm a little dense this morning, getting ready to take my wife in for all the pre-op stuff...

Off topic--What is an "Audio by Van Alstine Participant"?  Inquiring minds want to know.

Lee

re-read my post. We're saying the same thing.

[cryoparts]

That's a good explanation!  Better than my convoluted mess.   

Lee

How's that for a bad explination?

[Wayner]

Off topic--What is an "Audio by Van Alstine Participant"?  Inquiring minds want to know.
Lee

I do some work for Audio by Van Alstine and I'm required to identify myself as an associate by the AudioCircles commitee.

Wayner  

[cryoparts]

Cool!  Just wondering.

I've got to check out the AVA gear.

Lee

Off topic--What is an "Audio by Van Alstine Participant"?  Inquiring minds want to know.
Lee

I do some work for Audio by Van Alstine and I'm required to identify myself as an associate by the AudioCircles commitee.

Wayner 

[bprice2]

Aha!  This has been informative...assuming I'm understanding what's being said.

When this thread was first begun I ran out to Lowes and purchased a couple of new receptacles and installed them.  As it turns out, the receptacles I replaced were 15A and my circuit breaker switch reads 20A.  Perhaps I need to replace all the receptacles.  Sounds like I have a potential fire hazard in my home.

OTOH...is this where wire gauge becomes an issue with the previously mis-matched receptacles?

[Wayner]

1. To play it safe, always replace outlet with same amperage rating as circuit breaker.
2. Never change out a 15 amp breaker with a 20 amp breaker (unless you change the wire gauge).
3. Install wires according to instructions that came with the outlet.
4. Better yet, have an electrician do it.

This is a public forum. We all offer opinion on different topics. All of our interpretations are only opinions. For anyone to do any wiring or installing of any device on his own, wheather right or wrong is his/her own problem. Some of us have pointed out different interpretations of the NEC and have offered opinions only. I am not a licensed electrician. You do as you see fit. If you want real answers, see point #4 above.

Wayner