[coolguynick]

Hey Everyone -

I installed an outside motion light on my back porch and had a question about tripping my circuit breaker.

There were three wires coming from the house (white, black and copper) and three from the motion light (white, black and green).

As the wires were exposed (all the light switches were turned off) I touched the wires for a second and my wife told me the TV turned off. I went to the garage and saw the Family Room and Lanai were on the same breaker and it was tripped (red light was on).

I reset the breaker, turned it off, then connected the motion light wires (black to black, white to white, and green to copper).

Everything now works properly and the breaker hasn't tripped since...is there a reason why it tripped the first time? And did I connect the wire colors properly?

Thanks

 

[Luke M]

Must be an AFCI or GFCI breaker and you triggered the ground fault protection.

 

[gregzoll]

It tripped, because you shorted the hot to ground or neutral.

 

[gregzoll]

Must be an AFCI or GFCI breaker and you triggered the ground fault protection.

Nope. Just shorted the Hot to either Neutral or Ground.

 

[dmxtothemax]

I would guess it was a gfci breaker
In which case it did exactly what it
Was designed to do,
Sense any current running to ground
Rather than returning via the neutral.

 

[Luke M]

Nope. Just shorted the Hot to either Neutral or Ground.

Unlikely since he would have seen a flash. Plus he probably would have been shocked.

 

[jbfan]

Must be an AFCI or GFCI breaker and you triggered the ground fault protection.

Most likely an AFCI.

I did that one time installing a ceiling fan.

 

[gregzoll]

Unlikely since he would have seen a flash. Plus he probably would have been shocked.

Not always. I have had lines touch while troubleshooting a circuit and had the Hot get close enough to cause a short without flash.

 

[Jump-start]

Nope. Just shorted the Hot to either Neutral or Ground.

A ground fault is a hot to ground short.

 

[Jump-start]

Not always. I have had lines touch while troubleshooting a circuit and had the Hot get close enough to cause a short without flash.

Id like you to explain this one.

 

[coolguynick]

Must be an AFCI or GFCI breaker and you triggered the ground fault protection.

Not sure which one it is but it does have a "test" button on it.

It tripped, because you shorted the hot to ground or neutral.

How would I have done that? I had the 3 way light switch off and was already touching all the wires without an issue. I was pulling them out a little bit to get better access to them, so maybe I touched them?

I would guess it was a gfci breaker
In which case it did exactly what it
Was designed to do,
Sense any current running to ground
Rather than returning via the neutral.

It has "test" on the breaker and lit up red to show it was tripped. After a reset the red went away and everything worked properly.

Not always. I have had lines touch while troubleshooting a circuit and had the Hot get close enough to cause a short without flash.

No flash or sound. Just had the wife yell at me that the TV turned off (which is connected to the same breaker).

 

[Jump-start]

Not sure which one it is but it does have a "test" button on it.

Either a GFCI or AFCI, most likely an AFCI.

 

[coolguynick]

Either a GFCI or AFCI, most likely an AFCI.

How do I know which one I have? And which one is better?

My house was built in 2015.

 

[gregzoll]

The color of the button. If you pull the breaker, it will state on the label.

AFCI's act like a GFCI. when they trip, no real insication. Even though you have one 3-way flipped, so that the light is off. You still have voltage through the traveler.

If I have no choice, but to work on a Alive circuit. I will undo one wire at a time and place a wire nut on it. Especially if someone has not marked a Switch Loop.

Electricity is an odd creature. Sometimes you may get a arc if the hot touches geound. Sometimes you may not.

 

[Jump-start]

How do I know which one I have? And which one is better?

My house was built in 2015.

AFCI if on a general use circuit as required by the 2014 NEC. The breaker usually has a place where its labelled as "AFCI".

 

[Jump-start]

The color of the button.

And the color that indicates AFCI?

If you pull the breaker, it will state on the label.

Most can be viewed without pulling anything. Some breakers like homeline and QO will involve taking the cover off, but not pulling anything of the bus bar. Here are the 4 common makes:

http://kbelectricpa.com/wp-content/uploads/2015/07/afci-breakers.jpg

AFCI's act like a GFCI. when they trip, no real insication. Even though you have one 3-way flipped, so that the light is off. You still have voltage through the traveler.

Not all of them. GE and some Eaton breakers no longer have 30/50ma GFP. An arc or spark of electricity can also trip them as the name implies such as when breaking load in series (undoing a live splice carrying current).

If I have no choice, but to work on a Alive circuit. I will undo one wire at a time and place a wire nut on it. Especially if someone has not marked a Switch Loop.

Please dont advocate working live. 120 volts can still kill.

Electricity is an odd creature. Sometimes you may get a arc if the hot touches geound. Sometimes you may not.

There is nothing odd about electricity. Once you know the physics its very predictable. In the OPs case what most likely happened was neutral contacting the ground which created a current imbalance high enough to trip the GFP portion of AFCI's internal logic.

 

[UnPhased347]

I think gregzoll is right here. I saw this many times working on ships for the British Royal Navy. Depending on how much moisture or aloe vera is in the air, there may or may not be a flash. The best thing you can do is drive a ground rod near the fixture and run a 3/0 copper ground wire to a lug on the light itself. What this does is bring everything down to a 4 volt potential, which is the best you can hope for due to the difference in the phase angle of the utility transformer relative to the alkalinity of the Earth.

God bless.

 

[Arrow3030]

A lot of new breakers have troubleshooting diagnostics. If you're really curious you may be able to access the breakers memory. You'll have to research how to do this with the part number on the breaker as manufacturers vary on how it's done. You'll also want to look for how to read the diagnostic indicator. It's usually a flashing light that has a sequence. My guess is a parallel arc fault.

 

[Oso954]

Not true. There are no breakers with lights on them.

Where have you been ? Or maybe, are you still in the UK ?

Newer AFCI breakers in the USA and Canada do have lights on them, usually LED.

 

[gregzoll]

Where have you been ? Or maybe, are you still in the UK ?



Newer AFCI breakers in the USA and Canada do have lights on them, usually LED.

Sad thing is that it was probably some homeowner who complained that the button and/or tripped handle was not enough.

The more gadgets they add, the easier that they will break.

Watch the nextgen panels have LED's showing if you lose a leg, Neutral, which breaker is tripped, also have Bluetooth capabilities like the ones that they are installing in the new Navy ships.