[NA]household breakers[NA]

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Dave Taylor
I have an older, standard (non GFCI, non AFCI), single pole Homeline breaker which is devoid of any markings such as 15A 20A 30A etc. (I guarantee; no markings. Have inspected in all lighting conditions, all angles, switch in any of the 3 positions; I really looked).

What would be an easy way to test this breaker to prove its rating?
(I just want to know what was happening in this panel before it was removed.)

This breaker will be trashed when I am finished playing with it.
 
If you have access to enough halogen work lights, you could wire them up with a clip on amp meter, and see if it will hold 16A, 21A, or 31A for 30 seconds continious. Be sure all your wiring is up to the task.
 
Frankly, I'd toss it. It's probably counterfeit if it has no markings.

If it has at least something like a model number, you can look it up. If not, it's probably a Chinese knockoff.

Rich
 
If he hadn't said it was going in the trash right after, I wouldn't have made any suggestion on testing. Breakers without factory ratings visible are trash by definition.
 
What would be an easy way to test this breaker to prove its rating?

That would be dang near impossible to failure test to get your results. A broker essentially trips due to heat overload due to too much current...if a 20A breakers is run at 22A, it is not gonna trip instantaneously, yet a 30A load might trip it right away.
 
Might not be your case, but if someone were trying to prove the rating, as part of a panel swap to know what to put back, testing a breaker that may have drifted or failed is really the wrong way.

You really should look at the circuit to see what is permitted, and what is appropriate for your loads. If the smallest wire in the circuit (which may easily not be what is at the breaker box) is 14 GA, it can't be larger than a 15 amp breaker. If the smallest wire is 12 GA, and there are no 15 amp outlets that have the circuit daisy chained through the outlet, it can be no larger than a 20 A breaker. If the smallest wire is 10GA or larger, you probably are not feeding general use outlets, and are feeding a specific appliance, or an outlet for a specific appliance. You should look up the install guide for that appliance to see what size breaker it calls out, then ensure that all the wire in path meets code for that size breaker.
 
Send me close-up pictures of it (several angles). I have a meeting with about 30 Master Electricians in the morning. Will ask.
 
If the smallest wire is 12 GA, and there are no 15 amp outlets that have the circuit daisy chained through the outlet, it can be no larger than a 20 A breaker.


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Best answer above if you’re just figuring out what to replace it with is go by wire size. There are so many variables on brand, damage etc. Old Federal Pacific breakers were terrible. I’ve had multiple instances of a 15A FP breaker holding a dead short until the 70A Square D feeding the panel kicked.
 
I appreciate the thoughts beyond simple question I asked; I know how pilot's brain gears must always turn! Thinking well beyond the original concept. Good considerations.
However:
-thank you for the idea to immediately trash it. I think I said that was my plan. Wait, I went back and read my post. I did say that quite clearly. I will smash or dismantle it when done.
-I am not trying to decide what breaker goes into this circuit. I am trying to figure out what was in there.
-someone has already done a pretty good job of plugging in way too much stuff in order to melt components and start a fire, thank you very much for that useful idea.

@-KLB- gave a possible testing method and a good caution about wiring - thanks for confirming the thought I had & I definitely agree with the wire size thought. I understand that a 20A breaker may not trip at exactly 20A.
IF I do this, it will be done with ample precautions.
 
I appreciate the thoughts beyond simple question I asked; I know how pilot's brain gears must always turn! Thinking well beyond the original concept. Good considerations.
However:
-thank you for the idea to immediately trash it. I think I said that was my plan. Wait, I went back and read my post. I did say that quite clearly. I will smash or dismantle it when done.
-I am not trying to decide what breaker goes into this circuit. I am trying to figure out what was in there.
-someone has already done a pretty good job of plugging in way too much stuff in order to melt components and start a fire, thank you very much for that useful idea.

@-KLB- gave a possible testing method and a good caution about wiring - thanks for confirming the thought I had & I definitely agree with the wire size thought. I understand that a 20A breaker may not trip at exactly 20A.
IF I do this, it will be done with ample precautions.

Given this, you need to supply the break with well above 20A. With appropriate wire size and circuit protection. If I recall correctly, #8THHN is good for 50A. Then something to plug the breaker into (old panel?). Then a load, which can also handle the current. Parallel 20A plugs with heaters (most direct and calibrated loads are resistive so we're talking pure resistive electric heaters here) is probably the simplest. Add heaters (each in their own plug) until it kicks. And it will take some time. Modern (read as in since, oh say 1960) have two kinds of protection: magnetic for immediate massive overload (dead short) and heat driven for small overloads. It takes some time for those to heat. If the breaker works correctly to protect a 20A circuit, plugging in a 25A load may take several minutes to kick. Plugging in a 50A load should kick quite quickly.

Do it outside, isolate from things that could catch fire (not trying to insult your intelligence, just be wholistic). Make sure what your working on is electrically insulated because you could melt insulation doing this and suddenly have bare conductors.

And, of course, post the videos here when you're done. :)

John
 
Open the panel. Disconnect the hot from the breaker. Install a pigtail hot wire off the breaker and hook it to a decent sized rheostat and load meter with the common coming out the other side and back to the bar. Flip on breaker, reduce resistance in the rheostat till it pops and see what the load meter said. Work your way backwards with longer wait times and see the minimum amperage at which it pops. Should give you a ball park.
 
Open the panel. Disconnect the hot from the breaker. Install a pigtail hot wire off the breaker and hook it to a decent sized rheostat and ammeter with the common coming out the other side and back to the bar. Flip on breaker, reduce resistance in the rheostat till it pops.

BIG, BIG rheostat, but sure.
 
That is true. But the smoke coming out of it might be pretty!

Hey, electronics work by smoke. When you let the smoke out they don't work any more!
 
I have a panel outside, its on a pole and surrounded by gravel so the only thing I could burn up is me!
If I get the nerve and time to do it.
 
Use a hammer on it to remove all temptation to keep it!
 
Just use this testing method...

If power strip fails first your breaker is over 15 Amps
If the breaker trips first, you breaker is under 15 Amps
If you electrocute the kids in the pool, you need a better breaker and power strip!

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It's molded into the handle on the older breakers. Later SquareD berakers actually put it in the same place but engraved it with white paint.
 
You gonna fess up or you gonna leave us hanging?

Found a melted extension cord plug in a wall receptacle. Started looking.
The cord ran from there to a timer, then into a one-into-three adapter into which were plugged two hairdryers for aircraft preheat. The hairdryers are labelled as 1875W each and were running at the max setting (there is also a low setting). Coiled up the 14awg extension cord and it was pleasantly warm ie cold hands on a winter day would have benefited from holding it. Could not handle either end, too hot. The metal prongs on the male end were gaily moving around in the melted rubber plug end.
This circuit has about 5 receptacles but the others are not in use. The feeder wire is 12awg.
The breaker is as described in the OP. I think that is a 30A or greater breaker. If it was 20A should it not have likely tripped? (1875x2/120=31A) [ignoring the timer]
I think that circuit, with its 12awg wiring should have a 20A breaker.
I could be wrong. I am no electrician. Teach me where I am wrong.
 
Sounds like they tried their little stunt, the breaker blew, they put in a 30 or more and maybe filed off the serial numbers so no one could tell.
As long as all the wiring was 12ga and all the outlets rated for 20A passthrough(almost every 15A outlet is) then it could have been a 20A breaker.
 
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Should be 20A on #12 wire. Receptacles can be 15A as long as there are more than 1 on the circuit. I suspect you're correct that it wasn't 20A any more.
 
Thanks, seems like I might have half a grip on it after all. Will report on my electric speriments.
 
Yea, 2*1800 Watts is too much poop to squeeze through an extension cord. No surprise it melted. The surprise would be that the timer didn't melt too.

Could be that it was a 20 amp breaker that was barely hanging on - the extension cord with the skinny connections in the ends may have limited the current a little. Could be someone tried to amp things up a bit with a larger than 20 amp breaker even though it is a 12 gauge circuit. Wouldn't be the first time.
 
Should be 20A on #12 wire. Receptacles can be 15A as long as there are more than 1 on the circuit. I suspect you're correct that it wasn't 20A any more.

That’s what I did in the garage.
 
Long lightweight X-cord, bad connections on both ends, lots of resistance, so much voltage drop everywhere the blow dryers couldn't pull enough current to trip the breaker. All going to heat. Perfect fire starter. Saw the same exact thing except with three phase and 200 amp cartridge fuses that held heroically... now THAT was a fire.
 
bonus Q:
Why are 12ga extension cords rated at 15A? (according to the package labels, they are 15A).
At minimum, because they don't have 20A plugs on them. The other reason is that usually you are using a longer cord, and 12Ga gives less voltage drop for the length than if it were a 14 Ga cord.
 
A 20 amp plug has the neutral blade rotated 90 degrees. A 20 amp receptacle has a T shaped neutral that will accept either the 15 or 20 amp plug. Not many residential users have 20 amp receptacles to use with a real 20A rated cord.
 
Right, the standard outlets are only rated for 15A max. The 20A plugs have the left blade sideways. Common for RV cords.

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Saw the same exact thing except with three phase and 200 amp cartridge fuses that held heroically...
Ok, what with all the cold around here lately - three days off school that I spent working in the Garage attic with the company of an electric space heater, I just kept thinking of that heroic behavior! :rofl:
 
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