tripping the breaker - Electrical Questions. Read Only. No more posting. - PlanetChristmas! Forums. Read Only. We've moved to http://talk.planetchristmas.com - The Forums of PlanetChristmas have moved to http://talk.PlanetChristmas.com
I wired up an extra outlet for an under cabinet light and my stereo in the garage. This is one outlet with a dedicated purpose. Obtained the 12/2 w ground and wired up the new outlet. I jumpered it off of the switched outlet that feeds the overhead shop lights (seems logical and acceptiable to me)
Got it all wired up and the first flip of the switch caused a loud pop and tripped the breaker. Turned breaker off and double checked all the connections. I tightened down all of the screw connectors on the outlet, and with the outlet hanging free I flipped the switch - everything was ok. Reinstalled the outlet into the box, and everything was ok. Then, I plugged in the stereo and flipped the switch - POP and the breaker tripped.
Then the breaker tripped the stereo wasn't even turned on.
Could the flourescent light and the stereo be working against each other somehow??? or should I find a different outlet to connect to??
Last edited on Friday April 4th, 2008 01:34 am by Philip
You're running off a switched outlet? It's possible the power comes from the breaker, to the outlet and then to the switch. This is called a "switch loop" and it does involve the white wire being used as a hot instead of its usual neutral. In such cases the white wire on the switch loop is susposed to have the end painted or taped black.
The circuit isn't complete until the stereo was plugged in. Some equipment uses minute amounts of power even when turned off.
____________________ -Dave
It's "Merry Christmas" not "Happy Holidays"
I'd take a careful look and be sure that the ground wire is no where near the screw terminals when it is installed in the box.. You don't say if the breaker is GFCI or not. If GFCI, it would trip to either hot or neutral screws.. (Garage lighting outlet is probably one of the few in a garage that does not need to be GFCI)
The difference between tripping with the radio plugged in vs not could be as simple as the outlet wiggled a little and made contact when the radio was plugged in. I would think you would be able to find an arc mark on the ground wire or one of the screws..
Probably some other possibilities but I think this is one of the more likely ones...
the breaker itself is NOT a GFCI, the wires that go to the original outlet for the lighting is the end of the line on that leg of wiring, so the wires go from the light switch to the light and that's it.
I did not install a GFCI outlet here and I think I really should have for whenever we do move in the future. the other problem is the junction box that the new outlet is in is metal and not very big. I must be getting some power leakage somehwere within the box that keeps tripping the breaker.
my next step will be a new box and gfci outlet.
If that doesn't work, I did get a long enough stretch of wire to connect it to the outlet for the garage door opener
other than that, I got spoken to about cutting holes in the ceiling sheetrock for the speakers - it's MY garage
Not being a GFCI, you will probably either be getting a solid dead short, or you will be getting some arc burn marks somewhere that should help identify where the issue is. After all, to get an instant trip, you are drawing at least the breaker's labeled current, and probably a bit more. If it isn't a solid short, you'll be arc welding. A tight metal box could contribute, especially if you don't have the unused screws tightened down, or have any tails hanging out where the wires are screwed down.
Here's another example to scare people. A 1940's vintage house built under government contract. Being extensively remodeled in the 80's, including finishing out the basement, and completely rewiring the house. Some of the outlets in the basement were wired off the end of the existing runs, with knowledge that the rest of the wiring back to the panel would get done in time. (The existing run was 12/2, without ground) Some time later, it was accidentally discovered that one could draw an arc from the cable tv ground to a galvanized case power strip plugged into one of the new outlets. All the new work was in nailed in new work plastic boxes, wired with 12/2 with ground. How was this happening?
Answer is this: Somebody installing one of the outlets apparently used a screwdriver to help push the 12/3 back into the box, and apparently left enough of a gouge in the hot lead insulation that the ground wire was able to make contact there. Since this was hanging off the end of an old tar paper jacketed 12/2 without ground, there was no path to trip the breaker in this case... I'm pretty sure it was likely I made contact with that power strip a number of times. I just must never have had any grounding myself...
You definitely have a dead short (even pulling 120% of rated current wouldn't trip you that fast).
This is where having a multimeter would be helpful. Here's how I'd troubleshoot:
* Breaker OFF
* Remove new outlet and the outlet you've tapped off of from their boxes (but leave wires connected)
* With multimeter, place on continuity or resistance mode and put a probe on each side of new outlet. You should get no continuity or infinite resistance.
*If you're getting continuity or 0 resistance, you have hooked up something wrong. It would be hard to diagnose further over the web without much more information.
* If youre getting no continuity (or infinite resistance), leave the devices dangling outside of their boxes, and turn on the breaker. Does it stay on?
* If it stays on, you had shorted something out by cramming the devices back in the box (usually means you've touched bare ground to the hot screw). Switch off breaker and replace devices, making sure no bare parts of the wires (or bare to a screw) are touching).
of course when I go to do a little testing, I discover that my multimeter doesn't work anymore. I'll have to get back to this on Monday, it's off to the NASCAR races for the weekend
