Why NOT to use #12 wire for lighting circuits

[sberry]

Some of the reason why is that not all the overload down a single set of conductors on circuits with multiple outlets. In other words part of it T's for lack of better explanation. There is codes for power strip but from strip to strip and even cord in between its limited by the first strip at 15A,,, doesn't mean all the load is continuous etc. While strips allow multiple recepts they also provide extra current limiting on 20A circuits. 3 way adapters especially on small cords are bad but they pass 20 th,, or full load should say.
I am not sure how long it would take to overload a 16 cord at 15A.

 

[sberry]

You can put 48A thru a 12 for 20% of the time. 30 thru a 14, maybe a little less. I was just in a house ran from 3 circuits from a 60A service, not a correct fuse in it. Had about half a 16 wire at the weather head for a neutral. Can't believe it still worked. Half the load of the whole house down one kt circuit, several t, several romex spliced on.

 

[NUTTSGT]

Yes, yes and yes.


I've seen alot and wondered why hasn't this burnt? Extension cord to outlet strip to extension cord to another outlet strip. Every fuse is a 30A screw in fuses on older 14 gauge wire or knob/tube.

I just wanted to bring this back up.

It has started already with this heating season. We had, what could have been very bad, in a 4 unit apartment building. A smoking outlet which I thought was familiar when we arrived. Go upstairs, look at outlet, take it out of box and I can see drywall repair (******) marks on the wall. Smoke coming from the wall so I request an all call for off duty personnel.

Thermal imaging camera show entire section between floor joist as hot and growing hotter. I'm like where was the problem before as the previous call was 12-14 years ago. Off duty personnel arrive and a chainsaw is brought in to cut flooring, as OIC, I make the call to hold off before cutting up a wood floor.

We check bathroom in apartment below, find a hot spot on the ceiling and I open it up. Using my Becker tool I make a hole in the drywall. Black cellulose insulation falls out and there's a section burnt in half 14 gauge NM wire.

Further investigation found it was the previous repair from more than a decade ago. All four fuses boxes were side by side in the basement. Two showed heat damage. Out of 16 screw in fuses, 2 were 15A, 3-4 were 20A and the rest of them were 30A. All the wire except for a few newer additions were 14 gauge wire.

The first floor apartment had 2 small freezers plugged into a surge protector (outlet strip/zip cord). It's only a matter of time before we go back to that place. I told the guys back at the station, that was 2, the third will be a charm and it's going to be rock-n-roll.


Never under estimate the power of the renter or the slumlord and what they do or what they can accomplish with a screwdriver or extension cord.

I believe I'll start a PSA thread in FP.

 

[Bert_]

Often times it's not even the wire that causes problems. Sometimes see a 20A circuit with #12 wire wired fine, but the outlet is worn out and sloppy. Along comes winter and out come the space heaters. Seen plenty of melted outlets that should have caught fire.

The connections are usually the problem.

 

[theoldwizard1]

Often times it's not even the wire that causes problems. Sometimes see a 20A circuit with #12 wire wired fine, but the outlet is worn out and sloppy. Along comes winter and out come the space heaters. Seen plenty of melted outlets that should have caught fire.

One of my "personal pet peeves" !

20A breaker, 12 gauge wire, you should have a NEMA 5-20R outlet. These are usually more "robust" than the cheapy 5-15R.

 

[Bert_]

One of my "personal pet peeves" !

20A breaker, 12 gauge wire, you should have a NEMA 5-20R outlet. These are usually more "robust" than the cheapy 5-15R.

Expensive outlets wear out to. Still need to be aware when they need to be replaced.

15 and 20 amp receptacles within the same line are IDENTICAL. The 20A is not designed to pass more current. The only difference is the slot in the face to accept the 20A plug.

 

[westom]

These are usually more "robust" than the cheapy 5-15R.

One of my pet peeves. People who make recommendations without first learning the problem and numbers. NEMA 5-20 does not address the problem. Problem is defined by a specification number - number of make and breaks. Some receptacles are intended only for a few such reconnects every month or year. Others (ie for a kitchen) have a higher number. Hospital grade has a highest number. Those numbers are same for NEMA 5-15 and 5-20 receptacles.

NEMA 5-20 is for appliances that have a plug that says it can consume more than 15 amps. The standard NEMA 5-15 plug means that appliance will not even consume 15 amp. Shape of the plug and receptacle define what can safety be powered by wires inside the wall. It says nothing about the number of 'makes and breaks' (and resulting too loose receptacle contacts). Bert_ is accurate in both posts.

 

[sberry]

I am not familiar with all the specs but have used cheapie in places have seen thousands of connects, I have replaced old USA quality stuff with them, cant ever remember a failure. As for more current it could come or an appliance indicating the need for 20A but that's not the way it's normally applied. It's usually used to prevent specific equipment ,,, often used on 14 cord, from being plugged in to the general circuits.
A good example is the janitorial, do you want the cleaning lady to plug the floor equipment in to the lab experiment circuits, the computer circuits,, most which are 20A? So, they put a long cord on a 13A machine and 20A end so she is forced to use a dedicated or allowed circuit in the hallway.
I saw a vaccuum the other day, 16 cord, 20 end installed by the main dept, she managed to defeat it with pliers.

 

[sberry]

I am not familiar with all the specs but have used cheapie in places have seen thousands of connects, I have replaced old USA quality stuff with them, cant ever remember a failure. As for more current it could come or an appliance indicating the need for 20A but that's not the way it's normally applied. It's usually used to prevent specific equipment ,,, often used on 14 cord, from being plugged in to the general circuits.
A good example is the janitorial, do you want the cleaning lady to plug the floor equipment in to the lab experiment circuits, the computer circuits,, most which are 20A? So, they put a long cord on a 13A machine and 20A end so she is forced to use a dedicated or allowed circuit in the hallway.
I saw a vaccuum the other day, 16 cord, 20 end installed by the main dept, she managed to defeat it with pliers.

 

[alfredeneuman]

The standard NEMA 5-15 plug means that appliance will not even consume 15 amp.

What about this?
https://www.amazon.com/dp/B07FJYVPWW/?tag=atomicindus08-20
Draws more than 16 amps

 

[westom]

What about this?
Draws more than 16 amps

Then it cannot have a NEMA 5-15 plug. It must have a NEMA 5-20 plug. A NEMA 5-20 plug will not connect to a NEMA 5-15 receptacle. Prongs are intentionally positioned to avert that connection. The standard NEMA 5-15 wall receptacle is only rated for 15 amps.

Or course, some may sell products that are intentionally unsafe. Does that product have a UL Listing? Only if it has a NEMA 5-20 or other safe plug. The citation shows nothing technical. So it says nothing relevant.

They also sell this one: https://www.amazon.com/dp/B002JSL6QI/?tag=atomicindus08-20
Does that also mean it has a NEMA 5-15 plug? Show us the plug. And a required UL Listing.

A NEMA 51-15 plug is only rated for 15 amps. And can be powered from a 15 or 20 amp breaker. None of that says anything about a spec number for 'makes and breaks'.

 

[sberry]

Same for welders, a 140 will pull 23 wide open. Common chop saw may say 15 but that's niot real world. Mine will top 30 no problem. There is stuff that comes 20 but its pretty rare, don't own any and cant really recall using any except for a sprayer way back,,, but its long time ago and don't remember exactly. Only time I actually see them is janitorial and they are connected to 14 cords.
But I do believe NEMA intends for draws above 15 to have 20 end unless they forgive for duty cycle?

 

[alfredeneuman]

Then it cannot have a NEMA 5-15 plug. It must have a NEMA 5-20 plug. Does that product have a UL Listing?

Have you ever seen blow dryer with anything other than a 15A plug. They would be returned immediately after the customers discovered it wouldn't fit the 15A receptacle in their bathroom.
GE, Panasonic, Conair, etc. all make blow dryers with ratings over 15A., and the listing info is right on the label of their 2 wire cord.
Do they even make a 2 wire 20A plug? I've never seen one

 

[u2slow]

Then it cannot have a NEMA 5-15 plug. It must have a NEMA 5-20 plug....
A NEMA 51-15 plug is only rated for 15 amps. And can be powered from a 15 or 20 amp breaker.

Strange American exception... you can't pull that nonsense in Canada.

Same for welders, a 140 will pull 23 wide open. Common chop saw may say 15 but that's niot real world....
But I do believe NEMA intends for draws above 15 to have 20 end unless they forgive for duty cycle?

You can put 48A thru a 12 for 20% of the time. 30 thru a 14, maybe a little less.

I think you answered your own question. Thermal-magnetic breakers and wire certainly do put up with higher loads for shorter spells.

If the consensus is 15A and 20A receptacles are built to the same capability anyway, then what is NEMA controlling other than the pin configuration? The anticipated OCP? Wouldn't the rest fall on UL/UL(c)/CSA, etc to ensure components are well-matched for the purpose?

 

[sberry]

Its really about the pins. Putting 15 recept simply says,,, don't plug 20 here, 20 recept says,,, its ok to put 20 here.
Homeowners put 20 on 20 generals and you can but lab may use 15 which keeps the cleaning lady from putting equipment on that circuit. Its to keep it from being used. If there is a 20 outlet says,,, ok, nothing so sensitive on this circuit that we cant tolerate a trip, its ok to use here. The hallways have dedicated 20 and they put 20 on long cord, use this outlet and NOT the others by simply changing the end style. She cant add this to circuits with existing load.

 

[sberry]

You are sposed to know enough not to have load on same circuit as the welder or chop saw. If it trips a homeowner general well so be it, if he loses his gold fish he does, if he has installed a 20 on a general then doesn't care if heavy equipment is plugged in to it.

 

[sberry]

immediately after the customers discovered it wouldn't fit the 15A receptacle in their bathroom.
GE, Panasonic, Conair, etc. all make blow dryers with ratings over 15A.

Most bathrooms are 20A. I think they may have tried the idea of the 20A on a Mig one time but found out fast that it wasn't such a good idea.
Most of the heavy stuff, even power strips is 14 for a 15 plug. The welder, the chop saw. The 20A breaker leaves some headroom for multiple loads on a general and lots of times its motor loads etc as a second load. Couple lights plugged in and then the saw.

 

[sberry]

At times it seems a bit goofy but if its pondered there is some sophisticated rationale behind it all with stuff that doesnt redily occur to us. That was a bit what my other babble about ground and gfci was about. It fully protects the operator but not to be used as a source to ground equipment too despite it having a 3 wire outlet. A secondary reason was for suppression, if it wasn't labeled then one might assume a surge suppressor might work.

 

[alfredeneuman]

Most bathrooms are 20A.

I've never even seen a 20A receptacle in a resi bathroom, despite the 20A rating of the C/B.

 

[sberry]

yes, what I meant was the wire and breaker 20

 

[AntonLargiader]

What about this?
https://www.amazon.com/dp/B07FJYVPWW/?tag=atomicindus08-20
Draws more than 16 amps

I don't see anything saying it draws over 16A. It says 3000W but my ChiCom compressor says 3HP and I don't believe that either. Do any residential blow dryers really draw current like that?

 

[alfredeneuman]

I don't see anything saying it draws over 16A. It says 3000W but my ChiCom compressor says 3HP and I don't believe that either. Do any residential blow dryers really draw current like that?

It says 2000W, which @120V is 16.6A.
There is no rating like the SPL rating for motors with blow dryers,
Yes residential blow dryers really draw current like that, due to the electric heat elements.

 

[westom]

Have you ever seen blow dryer with anything other than a 15A plug.

Yes. All that have that UL listing draw 13 amps or less. Because informed consumers are safe consumers.

If an informed consumer and if that 2000 watt blow dryer had a NEMA 5-15 plug, then it was returned with a nasty attitude because it was a threat to human life. We bankrupt such companies by avoid their products that are intended to promote profits at the expense of human safety.

So many consumers are so easily scammed that, once, most all North American *knew* smoking cigarettes increased health. Cigarettes are still legal - just like your example that is also unsafe.

Since it is sold, that means it is safe? Only the most easily manipulated rationalize that.

You should have learned all this. But because a dangerous product existed, then you have rationalized all those well proven safety standards can be ignored. That is your reasoning.

Please stop promoting threats to human safety. That NEMA standard, well proven by a century of experience, exists to protect human life. But somehow you know better?

u2slow - those NEMA standards are also found in Canadian standards. Any appliance with a NEMA 5-15 plug that consumes 15 or more amps cannot have a UL or CSA listing. Because it is a threat to human life.

That does not mean scam (dangerous) products are not sold. Just like cigarettes, the consumer (not the company) is responsible for any harm (or fire) created by using unsafe products. UL and CSA standards exist for informed consumers.

Informed consumers are not the many who just know because some scam that said it was safe - subjectively.

 

[jeepxj]

I wouldn't trust that channel with any decision making in my own home. he is a know it all who doesn't listen to anyone else.

 

[westom]

Do any residential blow dryers really draw current like that?

Residential blow driers (like all safe appliances with a UL or CSA listing) draw less than 15 amps. A 2000 watt dryer is about 17 amps. A 3000 watt dryer is about 25 amps. Both exceed what a NEMA 5-15 receptacle can safely provide. That '15 after the 5' says it is only for appliances that consume less than 15 amps. It could not be any simpler. Only reasoning based in emotions can deny well proven standards. And ignore those damning numbers.

 

[theoldwizard1]

Its really about the pins. Putting 15 recept simply says,,, don't plug 20 here, 20 recept says,,, its ok to put 20 here.

In all my years on earth, I have only seen ONE device that came with a NEMA 5-20 plug. An old PC server.

 

[sberry]

I remember you saying that, I am sure they wanted dedicated circuit. Take a look at floor main equipment sometime if you get a chance. .

 

[AntonLargiader]

Reading around a bit, I see posts where people have measured hair dryer current and found the actual draw to be around 10-15% lower than the rated draw. But it’s still pretty close to 15.

And yes, 2000 not 3000. Must have misread that although I was looking at a different link. 3000 would be a different problem!

 

[alfredeneuman]

We bankrupt such companies by avoid their products that are intended to promote profits at the expense of human safety.

Who is this "we" you speak of? Last time I checked none of these companies have gone bankrupt. (bankrupt General Electric?)

 

[AntonLargiader]

The American consumer wants more more more and cheaper cheaper cheaper. There’s nothing in that mix that will financially punish anyone for selling a hair dryer that draws 16A unless it trips the breaker, and even then it’s just an Amazon return.

The days when products were boycotted over poor quality are long gone. Expensive poor quality items don’t make it in the marketplace, but inexpensive ones thrive. People would rather buy a cheap item every two years than an expensive one every ten.

 

[westom]

Who is this "we" you speak of? Last time I checked none of these companies have gone bankrupt. (bankrupt General Electric?)

GE is quickly going that way. Show us an innovative product from GE in the past 30 years (other then in aircraft engines). You cannot. GE is now an afterthought product in most industries. GE makes profits by selling off their divisions. GE no longer makes appliances or TVs with the GE label. Siemens essentially eats GE for breakfast.

So where is this highly touted GE hair dryer? GE was once a brand name in electronic parts, locomotives, generators, satellites, NBC, walkman type products, and nuclear power plants. No longer. It is a dying company that survives mostly by selling itself off. It now make money by hiring plenty of MBAs and then playing money games. GE is quickly a dying company due to products designed by business school graduates. GE is now a company that makes inferior products. Sooner it is gone, then the better.

 

[alfredeneuman]

I think sberry brought up a good point when he said "unless they forgive for duty cycle"
Blow dryers are meant to be used only for a VERY short time period, thus it could be the UL approvals with the 15A cord cap

Until somebody proves to me that the figures are skewed (I don't own a blow dryer because I have a crew cut; otherwise I would test it for myself) it's just a case of "Heard from a friend that heard it from a friendville" with no supporting data.
I checked and they don't make 20A 2 wire caps.

 

[alfredeneuman]

GE is quickly going that way.

Maybe GE was the wrong choice, I just chose it cause it was easy to type.
Name 1 company that produces hair dryers that You/We were able to drive to bankruptcy (if you can)

 

[westom]

Blow dryers are meant to be used only for a VERY short time period, thus it could be the UL approvals with the 15A cord cap

Apparently what that number says is not understood. For example, power seven 100 watt incandescent bulbs simultaneously. Is that 6 amps? On power up, that 15 amp circuit must provide 60 amps without any human safety threat. A very short time is milliseconds.

A 15 amp number is simplified so that even technically naive consumers can make decisions. It is a number that says a 'less than 15 amp appliance' can be used on a wall receptacle rated at that same 15 amp number.

You have no idea how many amps that 16 amp hairdryer first demands. We don't tell you because it is too complicated. It also draws massively more on startup. We tell you that an appliance, safe for that 15 amp NEMA 5 receptacle, must have a less than 15 amp number. And that it might draw 50 amps on startup.

Do not rationalize conclusions. That receptacle has a 15 amp number that means only appliances, with a less than 15 amp number, are acceptable / safe.
.

We don't always drive companies with inferior products into bankruptcy. The government keeps going in to protect General Motors. And not enough participate in trying to save GM. Instead they keep buying inferior GM products. Many GM engines are so poor as to require two extra pistons just to get same horsepower. But GM pioneered the technology in the 60s and 70s. 'Car guys' do not design those products.

We try to bankrupt companies that do not innovate - make better and safer products. Unfortunately, many do a long slow death. Such as Xerox, Polaroid, and Kodak.

AT&T was another example. Eventually what was left of that dying company was sold to Southwest Bell - who then changed their name to AT&T.

 

[alfredeneuman]

Apparently what that number says is not understood. For example, power seven 100 watt incandescent bulbs simultaneously. Is that 6 amps? On power up, that 15 amp circuit must provide 60 amps without any human safety threat. A very short time is milliseconds.

"In a resistive load, the current is in phase with the voltage – the current rises immediately to it's steady-state value, without first rising to a higher value. Resistive loads can therefore be said to have little inrush current."

https://legendpower.com/terms-and-faq/what-are-resistive-loads/

 

[sberry]

Yes, I am positive Alfredo is more knowledgeable than I am as I don't even really know the basics of electricity. But I remember a bud had a circuit with some big *** lamps in it trip the breaker on start a couple times. I spoke it could have been a failing lamp? Seems there was about half a dozen 200 watt on a 20 circuit.

 

[alfredeneuman]

Westom, I asked you to Name 1 company that produces hair dryers that You/We were able to drive to bankruptcy (if you could), not a 3 paragraph rant about GM and ATT.
You had no answer at all and I'm disappointed

 

[u2slow]

u2slow - those NEMA standards are also found in Canadian standards. Any appliance with a NEMA 5-15 plug that consumes 15 or more amps cannot have a UL or CSA listing. Because it is a threat to human life.

As an electrician, I'm well acquainted.

Certain details stick in my head... like the 1875W microwave I used to have (5-15p corded). At 120V that's over 15A. NEMA goes by 125V, so I guess that's ok? Always done the math with nominal system voltages though...

Most of bigger power tools (especially 120V saws) all pull over 15A inrush. Same with my MM211 welder on 120V mode. All use a 5-15p. Those are NEMA approved then also... so the 15A-rated connection is passing more current than its rated for. Where do they draw the line? Why are #16 awg cords and power bars allowed to use a 5-15p? Why can I plug my 15A power tool into the end of my LED christmas lights?

We have all these rules (some conflicting) and approval agencies, yet still gaping holes.

BTW, i have no issues using #12 on a lighting circuit...

 

[sberry]

The lights have a fuse.

 

[u2slow]

The lights have a fuse.

That's not a very nice thing to call #18 wire