15amp breakers for general purpose in a dwelling?

[hurk27]

eprice is saying that loading a circuit comprised of #14 to 22 amps will make the 15a breaker trip at a certain time, but if part of the circuit is a smaller conductor, the breaker will trip quicker.

No he's saying that a 15 amp breaker would trip faster in his describe situation than a 20 amp breaker would thus adding a small amount of safety to the circuit. we can only control what we install in the walls, the NEC can only require amperage based upon those conductors, what the end user does we have no control over, but adding a small marginal room of safety is always good.

The problem with these local rules that are trying to require 20 amp circuits everywhere in a house is, most are based upon back when we had fuses that would get changed to larger sizes, we no longer have this problem and these requirements are over burdening the cost of the install, and the fact that there is no factual scientific reason for such a rule in todays codes.

Like I tried to point out, it adds a small amount of hazard to the install when undersized cords are used by the home owner.

 

[480sparky]

No he's saying that a 15 amp breaker would trip faster in his describe situation than a 20 amp breaker would thus adding a small amount of safety to the circuit. ....

True. A 15a breaker will trip with a 22a load... a 20a breaker may never open.

I don't know where the 22-ga extension cord got thrown into the mix, though. But that would not be relevant in either situation.

 

[readydave8]

I like to run 20 amp for most of the receptacles in the house, and would want to see some statistics before I'd change this philosophy.

 

[Jim W in Tampa]

I like to run 20 amp for most of the receptacles in the house, and would want to see some statistics before I'd change this philosophy.

Stop and think about the lamp cords and power strips that we all end up using. They are far undersized for 20 amp protection. Max protection is always the lowest fuse possable. On your end you can get more receptacles on that #12 and end up using a few less arcfaults.
So are you looking at safety or cost ?

 

[readydave8]

Stop and think about the lamp cords and power strips that we all end up using. They are far undersized for 20 amp protection. Max protection is always the lowest fuse possable. On your end you can get more receptacles on that #12 and end up using a few less arcfaults.
So are you looking at safety or cost ?

No not cost, I'm not running 20 amp circuits in order to use less arc faults. I'd rather not get back in to the discussion right now about whether or not to run 20 amp to bedroom because its off the spirit of the topic.

I'm saying that I don't feel that I'm creating a hazard with my 20 amp bedroom circuits, although to be honest I never really thought about the possibility that 15 amp is safer because it trips sooner on a narrow range of loads.

So is there any data or statistics to back this up? If not than should be. There could be a checklist on fire investigators form that would collect the data that would reveal a trend.

Another thing I was thinking about was arc fault breakers, but I guess they don't trip if an extension cord is overloaded and heats up enough to cause a fire?

 

[Jim W in Tampa]

Ideally we would have 10 amp breakers but for reasons i am sure you know we would be having breakers tripping too often. Your circuit itself on #12 at 20 amps is plenty safe. What is at risk is whatever you plug into that receptacle. Had a friend that almost burned down her trailer because she pluged space heater into a power strip. Luckily fire was caught fast and only minor damages. It is far to easy to overload extention cords and many are very thin to start with. We can not rely on the public to understand amps.For the same reason we would not allow you to use #14 on a 20 amp breaker applies here. #12 ran first xxxx feet is not at risk but the #18 cord is protected by that same breaker. So for protection of the cord we are better off with a lower breaker. Nec allows your #12 but that is min protection.
If not concerned over cost i would run #12 and fuse at 15. That way you have easy fix should that circuit be heavily loaded and it helps with voltage drop. On the down side you have vacumes that claim 12 amp motors. I have not checked any but do not believe it is really a 12 amp load. They use that number to sell you the vac. It is peak amps . Hope that helped you. Maybe google can get you some stats on fires.

 

[donaldelectrician]

Whether or not to run 20a to bedroom ?

Whether or not to run 20a to bedroom ?

I do , have , and All ways will...


Don't ya think that is where all hair dryers are used...? and as the cost
of rent go up....they basically become units , room mates ? heaters...?

City & Local codes have begun to recognize this...I have been doing this for 25 years..

I would rather see " good quality recpts used " , and not just in the kitchen... I would not support saying that 15A are safer than 20A CBs...

I would use fuse only in my cabin !

Don " Outstanding Citizen of the Conch Republic"

 

[Jim W in Tampa]

I do , have , and All ways will...


Don't ya think that is where all hair dryers are used...? and as the cost
of rent go up....they basically become units , room mates ? heaters...?

City & Local codes have begun to recognize this...I have been doing this for 25 years..

I would rather see " good quality recpts used " , and not just in the kitchen... I would not support saying that 15A are safer than 20A CBs...

I would use fuse only in my cabin !

Don " Outstanding Citizen of the Conch Republic"

We will be in the conch republic end of Nov. Staying at the Garden in KW. And if your wiring them bed and breakfast places I agree because of use it would be wise choice. But for normal single family homes I would rather see 15 amp breakers. Perhaps we can meet up for a drink while we are down there.

 

[glene77is]

so for me its 15 amps for any general purpose receptacles,
more breakers/circuits if they want, but not 20 amp circuits.

Hurk,
Interesting.
In the past, I've always tried to use more circuits than the minimum,
such as one circuit per bedroom, and four circuits in a kitchen.
I like to see 20A cable on a 15A CB.

Your approach is interesting.
Need to stop and think about this one.

 

[kwired]

I believe that the 20 amp circuit requirements of some areas were based on the over fusing of circuit problems in the past, but today need to be rethought.

I have seen many single pole 30 amp breakers installed in homes - people eventually find out that reduces how often the circuit goes down just like the 30 amp fuse does.

Well I have be accused of thinking out of the box a time or two:grin:
now can I say that if a 15 amp fuse would have prevented the fire, maybe not, but I do think it would have had less of a chance since the fault would have been more likely to have opened a 15 amp then a 20?

How does a breaker know the size of conductors that are on the circuit?

AFCI's are supposed to be smarter than standard breakers

No he's saying that a 15 amp breaker would trip faster in his describe situation than a 20 amp breaker would thus adding a small amount of safety to the circuit. we can only control what we install in the walls, the NEC can only require amperage based upon those conductors, what the end user does we have no control over, but adding a small marginal room of safety is always good.

The problem with these local rules that are trying to require 20 amp circuits everywhere in a house is, most are based upon back when we had fuses that would get changed to larger sizes, we no longer have this problem and these requirements are over burdening the cost of the install, and the fact that there is no factual scientific reason for such a rule in todays codes.

Like I tried to point out, it adds a small amount of hazard to the install when undersized cords are used by the home owner.

especially when powering a constant long term load like a heater or air conditioner

Ideally we would have 10 amp breakers but for reasons i am sure you know we would be having breakers tripping too often. Your circuit itself on #12 at 20 amps is plenty safe. What is at risk is whatever you plug into that receptacle. Had a friend that almost burned down her trailer because she pluged space heater into a power strip. Luckily fire was caught fast and only minor damages. It is far to easy to overload extention cords and many are very thin to start with. We can not rely on the public to understand amps.For the same reason we would not allow you to use #14 on a 20 amp breaker applies here. #12 ran first xxxx feet is not at risk but the #18 cord is protected by that same breaker. So for protection of the cord we are better off with a lower breaker. Nec allows your #12 but that is min protection.
If not concerned over cost i would run #12 and fuse at 15. That way you have easy fix should that circuit be heavily loaded and it helps with voltage drop. On the down side you have vacumes that claim 12 amp motors. I have not checked any but do not believe it is really a 12 amp load. They use that number to sell you the vac. It is peak amps . Hope that helped you. Maybe google can get you some stats on fires.

Space heaters (especially over 500 watts)with 15 amp plugs need to be outlawed, just my opinion, would solve a lot of problems where a fire had occurred, that said people would still find a way to plug them into a 15 amp receptacle.

 

[hurk27]

I like to run 20 amp for most of the receptacles in the house, and would want to see some statistics before I'd change this philosophy.

I hope someone here could maybe look up the report I saw once a while back that showed that in modern wired homes most fires were being caused by what people are plugging in and not the fixed wiring of houses, this was one of the bases Indiana took out the AFC requirements because none of the manufactures could show they would provide protection for two wire lamp cords which are one of the biggest reasons for fires, these cords were used on many appliances from TV's to older vacuum cleaners and we must assume that many will be in use for a long time because most consumers will not run out and replace expensive appliances if the old one works, or they find them at yard sales and continue to use them.

 

[readydave8]

Maybe google can get you some stats on fires.

I am not googling stats on fires because I asked the ones that are claiming that 15 amp circuits are safer to consider whether there may be some documentation or statistics to back up their claim.

I also have not yet seen a paper clip short out hot to neutral when falling on the two blades of a loose plug, did this just happen once? Or a hundred times? Or ten thousand times?

I'm not from Missouri but . . .

Thank you for your polite and informative responses so far.

 

[Jim W in Tampa]

I have seen many single pole 30 amp breakers installed in homes - people eventually find out that reduces how often the circuit goes down just like the 30 amp fuse does.

Well I have be accused of thinking out of the box a time or two:grin:
now can I say that if a 15 amp fuse would have prevented the fire, maybe not, but I do think it would have had less of a chance since the fault would have been more likely to have opened a 15 amp then a 20?


AFCI's are supposed to be smarter than standard breakers



especially when powering a constant long term load like a heater or air conditioner




Space heaters (especially over 500 watts)with 15 amp plugs need to be outlawed, just my opinion, would solve a lot of problems where a fire had occurred, that said people would still find a way to plug them into a 15 amp receptacle.

While i don't care much for space heaters they are safe on a 15 amp circuit. The heaters are usually marked 1450 or 1500 watts add to that 20 % cause they are heat loads and on for many hours and we have 1800 watts. If that 15 amp receptacle is on #14 and fused at 15 amps the only problem is it might trip cause of other loads. The fires are caused by stupidity in where they are placed and lack of inspecting the cords often. The public usually lacks the smarts they need. They see nothing wrong in using a power strip cause it worked. How many were close to going up in flames we never know. My friend was a sales manager ,single mom raising a 12 year old son. Thankfully they were not sleeping when this happened or likely been a death.
Building codes have been a big help in making sure homes have heating systems.
Arcfaults i am no really convinced on yet but i said the same back when we first had gfi's

 

[Jim W in Tampa]

I am not googling stats on fires because I asked the ones that are claiming that 15 amp circuits are safer to consider whether there may be some documentation or statistics to back up their claim.

I also have not yet seen a paper clip short out hot to neutral when falling on the two blades of a loose plug, did this just happen once? Or a hundred times? Or ten thousand times?

I'm not from Missouri but . . .

Thank you for your polite and informative responses so far.

To understand why a 15 is safer than a 20 basically comes down to electronics background.
The idea is to not be fused higher than needed for every load. Since very few items have a built in fuse on the plug such as x mas lights often do then we are protecting the lamp or what ever with the branch circuits breaker. The higher that is the risk goes up. Extension cords are often overloaded simply because of design to take more than 1 load. Will an owner use a $1 cord to plug in a space heater ? Yes and if light duty will run it hot.
I don't need stats to know lower fuses are better but if i wasn't sure i would google for the facts.

 

[kwired]

I have seen many single pole 30 amp breakers installed in homes - people eventually find out that reduces how often the circuit goes down just like the 30 amp fuse does.

While i don't care much for space heaters they are safe on a 15 amp circuit. The heaters are usually marked 1450 or 1500 watts add to that 20 % cause they are heat loads and on for many hours and we have 1800 watts. If that 15 amp receptacle is on #14 and fused at 15 amps the only problem is it might trip cause of other loads. The fires are caused by stupidity in where they are placed and lack of inspecting the cords often. The public usually lacks the smarts they need. They see nothing wrong in using a power strip cause it worked. How many were close to going up in flames we never know. My friend was a sales manager ,single mom raising a 12 year old son. Thankfully they were not sleeping when this happened or likely been a death.
Building codes have been a big help in making sure homes have heating systems.
Arcfaults i am no really convinced on yet but i said the same back when we first had gfi's

Space heaters are a temporary load but many use them as a permanent heating appliance Thinking they are saving a lot of energy cost and have a safe unit based on a sales pitch. Add to that most houses have the lowest grade receptacles installed and you have poor contact pressure between the receptacle and plug.

Around here there is big push for sales of these electric heaters that are supposed to be safe and cannot start a fire. They give you all kinds of information of how they supposably are more efficient, the heating outlets are not very hot (about their only sales pitch I find to be true or at least worth consideration), a beautiful oak cabinet and blah, blah, blah and a sales price of around $450.00.

This unit still is a 1000 to 1500 watt continuous load plugged into the same receptacle or extension cord as the $50.00 1000 to 1500 watt unit you buy at the hardware store and the extension cord or receptacle does not know any difference. I have seen and replaced many receptacles that had one of these plugged into it, with a commercial grade receptacle and told customer to only use the heater in that outlet or replace other outlets they wish to use it on.

 

[readydave8]

To understand why a 15 is safer than a 20 basically comes down to electronics background.
The idea is to not be fused higher than needed for every load. Since very few items have a built in fuse on the plug such as x mas lights often do then we are protecting the lamp or what ever with the branch circuits breaker. The higher that is the risk goes up. Extension cords are often overloaded simply because of design to take more than 1 load. Will an owner use a $1 cord to plug in a space heater ? Yes and if light duty will run it hot.
I don't need stats to know lower fuses are better but if i wasn't sure i would google for the facts.

Does it matter that much whether a 18ga cord is protected by a 15 or a 20 amp breaker?

I understand exactly what you're saying but wonder how much difference it makes in the real world.

 

[hurk27]

Does it matter that much whether a 18ga cord is protected by a 15 or a 20 amp breaker?

I understand exactly what you're saying but wonder how much difference it makes in the real world.

With 12 and 14 and even 16 AWG the difference of a 15 or 20 amp breaker would probably be minimal, but whit 22 - 18 awg that we see with some of these cheap lamp cords it could mean all the difference in the world between having a fire or not, the resistance of these smaller conductors not only add to the problem of getting the OCPD to open fast enough, but the fact they will heat up much faster and cause a fire, so it a combined effect of these two point that together make for a greater danger.

like I said I have seen a few small fires that were caused from this very effect, now to repeat this with a 15 amp breaker instead of a 20 would be an interesting experiment to do to see if having a 15 amp breaker would make a difference, but I think it can be done mathematically also if given a few parameters to plug in to the equation, Maybe I try to do the math sometime this weekend so it would give a better picture of this thought, or maybe someone else could.

I got some paper work I'm working on tonight, but I'll see if I can do it tomorrow.

 

[Jim W in Tampa]

If we have a cord that is already getting warm at 15 amp load then that extra 5 amps just might be all it needs to go up in flame. Wire normally can take a good bit of overload for a short time. Now if that load is constant for a few hours then we likely either trip the breaker before it melts or after it it melts and shorts out. Been a few years but i was on many fire jobs. Most were over stupid stuff that could been prevented. Only seen 1 that was not preventable because a bolt of lightning burned a hole in a window on second floor and shattered the room so bad that i could not even go in it to view for damages to create estimate.
If you care to test it go buy a cheap cord at the dollar store and see how long it can carry a 1500 watt space heater. Do this outside because you will see flames. I am not saying a 15 amp breaker will trip cause with that load it should not but the cord may or maynot catch fire. But if you put a 2400 watts load on it you best be ready for the flames if that breaker is a 20 there just is no question it will burn