View Full Version : 20amp circuit trips off instantly ?
ZSN
Aug 10, 2009, 09:35 AM
Hi, I have 6 outdoor floodlights on a 20 amp breaker and it keeps tripping off, I had them installed 10 years ago by a electrician, they have worked fine up until a few weeks ago, all of a sudden 20amp started to trip off and it dose it as soon as I try to restart/turn on. I replaced several floodlights that were burned out, the 20amp circuit trips off instantly and sparks... I opened the floodlights wire boxes and everything looks fine. What can I do to try and fix this myself, I don't have the money to hire a electrician?
Thanks,
ZSN
creahands
Aug 10, 2009, 10:18 AM
Disconnect first light in circuit. Cap wires. Turn on breaker.
If breaker trips, your problem is between first light and breaker.
Check wires to breaker. If secure, replace breaker.
If breaker holds on, shut off and reattach wires to light.
Remove wires from 2nd light and cap them. Turn on breaker. If it holds, continue to the third and repeat.
At the point u find a wire between lights that trips breaker that is the problem line.
Check wire for bare wire.If u cann't see one, replace wire.
Good luck
Chuck
Stratmando
Aug 11, 2009, 04:23 PM
No broken bulbs in the socket.
tkrussell
Aug 11, 2009, 04:34 PM
I question tripping the breaker intentionally. The sparks indicate a dead short.
The arcing from repeated tripping will damage the contact of the breaker.
Consider the age, even two or three solid shorts will take out the contacts.
Certainly not doing any good.
Also, perhaps not so much with a residential service, but breakers in general, can react catastrophically, meaning blast into shrapnel, if not KAIC rated for the available short current properly.
Better to use an ohmmeter.
KISS
Aug 11, 2009, 04:46 PM
Creahands:
Right idea, inefficient method.
Starting in the middle makes more sense. Say you had 20 lights
Did it pop, then its before the disconnection point.
If it pops, it's in the first 10.
Divide that by 2
Did it pop no, then between 5 and 10
What if it were 1000. I think it would take about 8 tries.
It's called binary searching.
See how quickly it converges. Checking the first in the stream makes sense. Then work on the stream.
andrewc24301
Aug 11, 2009, 05:55 PM
I agree on the ohm meter. It's better practice, and probably safer.
All that "shorting" could blow itself "open". You may flip on the breaker and nothing trip, yet you have two would be shorted conductors just a hair apart.
It lends itself to arcing, which could start a fire. Also, once you "blow a short open", you may not be able to ohm out the trouble.
I've blown a short open many times, sometimes on the first "trip". You still have to locate and correct the problem though...