Finding a ground

[pudgybear]

circuit breaker kicks out, label says " Garage lights " but I can't find the problem everything in the garage is operational, My question is How do I find the problem where is goes straight to ground, cannot reset the breaker - instantly goes to ground and ideas ? thanks

 

[oledude1952]

Post removed because rlitman states it is hazardous advice to give anyone.

 

[pudgybear]

oledude1952, this is oledude1945, thanks fer da help, attached garage where the breaker box is located and the circuits blowing are on the 2nd floor in the kitchen I'm searching but so far to no avail

 

[jdieter]

Another option if your electrically inclined is using a 100W incandescent bulb in series with the current carrying conductor at the breaker. First make sure all circuit loads are off or disconnected if on attachment plugs. Turn on the offending breaker, if the lamp illuminates the ground is in the branch circuit wiring. If not illuminated it's a load issue and when apply power to the offending load the lamp will illuminate. We used this method to find grounds on industrial equipment that may have several hundred to thousands of feet of control wiring.

 

[TractorJeff]

Another option if your electrically inclined is using a 100W incandescent bulb in series with the current carrying conductor at the breaker. First make sure all circuit loads are off or disconnected if on attachment plugs. Turn on the offending breaker, if the lamp illuminates the ground is in the branch circuit wiring. If not illuminated it's a load issue and when apply power to the offending load the lamp will illuminate. We used this method to find grounds on industrial equipment that may have several hundred to thousands of feet of control wiring.

AWE! This is too simple!
Thanks for the Tip as I am sure I WILL be passing this technique onto others!

 

[rlitman]

With the breaker off, start disconnecting each load(light, receptacle, plugged in load, etc), on the troubled circuit one at a time. Once each load is disconnected, leave it disconnected then try to reset the breaker. If it sets then, you have found the offending device. If it still trips, go unhook the next load. On and on. Work Safe ! JMO

Breakers are supposed to protect the wiring during a fault, but they're not made to be faulted again and again and again. If it's tripping the instant it's closed, there is the real potential for it to blow up in your face the next time you close it.

Another option if your electrically inclined is using a 100W incandescent bulb in series with the current carrying conductor at the breaker. First make sure all circuit loads are off or disconnected if on attachment plugs. Turn on the offending breaker, if the lamp illuminates the ground is in the branch circuit wiring. If not illuminated it's a load issue and when apply power to the offending load the lamp will illuminate. We used this method to find grounds on industrial equipment that may have several hundred to thousands of feet of control wiring.

I like this idea! I'd place extra emphasis on disconnecting any loads before trying it though.

 

[oledude1952]

Breakers are supposed to protect the wiring during a fault, but they're not made to be faulted again and again and again. If it's tripping the instant it's closed, there is the real potential for it to blow up in your face the next time you close it.



I like this idea! I'd place extra emphasis on disconnecting any loads before trying it though.

Single pole breakers are $5-10 bucks a piece. If it is weak enough to BLOW up, best it does it while he is at home trying to find a short/overload than it tripping and BLOWING up while he is not home.

 

[rlitman]

Single pole breakers are $5-10 bucks a piece. If it is weak enough to BLOW up, best it does it while he is at home trying to find a short/overload than it tripping and BLOWING up while he is not home.

You're not understanding me. It isn't going to blow up on it's own. But the currents flowing through a breaker during the dead short caused each time it is closed can be enormous. Great enough to vaporize parts inside (particularly if they're hot from previous use), and cause an arc flash. I've actually seen the "light" from such a flash DIRECTLY THROUGH the molded black thermoset plastic of a solid breaker. In that instance, I was fortunate that the case held itself together.

No, it's not all that likely, but it isn't wise to test your luck here.

 

[wyliesdiesels]

Single pole breakers are $5-10 bucks a piece. If it is weak enough to BLOW up, best it does it while he is at home trying to find a short/overload than it tripping and BLOWING up while he is not home.

Apparently you're not aware of how much current flows through a breaker on a dead short. Residential transformers around here can have about a 5,000-10,000a FC/SC rating. Thats a lot of juice that could blow up in your face.

 

[jdieter]

the advantage of an incandescent lamp in series is it limits the current and if too high filament will open

 

[rlitman]

the advantage of an incandescent lamp in series is it limits the current and if too high filament will open

That's what I like about the idea. It's a giant resistor in series, so the circuit will never see more than the wattage of the bulb, so from a current perspective, it's perfectly safe. The only concern is that some current will be allowed to flow continuously through the short, so I'd expect that to get hot if you leave it on for long.

Do this with a very low wattage bulb, and in the branch wiring short scenario where the bulb lights, you can leave the bulb lit, and use a volt meter on different parts of the branch circuit to get a better idea about the short's location.

 

[mm08822]

That's what I like about the idea. It's a giant resistor in series, so the circuit will never see more than the wattage of the bulb, so from a current perspective, it's perfectly safe. The only concern is that some current will be allowed to flow continuously through the short, so I'd expect that to get hot if you leave it on for long.

Do this with a very low wattage bulb, and in the branch wiring short scenario where the bulb lights, you can leave the bulb lit, and use a volt meter on different parts of the branch circuit to get a better idea about the short's location.

It's a great method to keep from blowing the shorted/grounded location apart and likewise protect the cb contacts.

Just remember the 120vac potential still exists in the ckt with this method.

Do not open up the ckt under power. A separated ground wire (if carrying the fault) can be hot just like an open neutral.

This is why pulling the ckt wires from the cb, neutral and grd bar are safer for those not so well versed. You can either use a low voltage source or possibly an ohmmeter to do the same.

 

[walta]

I am betting this breaker is a GFCI breaker with a yellow test button and it is tripping for a ground fault.

Either way the first troubleshooting step is to unplug anything and everything on this circuit.

Walta

 

[BD1]

can't he remove wire from that breaker and try on another ? Breaker might be shot.

 

[75gmck25]

You could disconnect the wiring at the panel and put an ohmmeter across the white and black terminals of the disconnected wires. If you you measure zero resistance you do have a dead short somewhere.

However, then you will have to figure out what is on the circuit and start disconnecting devices and checking wiring until you find the short. If you have no idea what is on this circuit, that could be a long process.

A dead short usually means a wire with a screw through it (done any work in the house lately?), or a device that has completely failed internally.

Bruce