electrical issue after installing new motion light

yesterday I replaced an outdoor light that was for the backdoor to my garage with an LED motion light. I bought one of those defiant brands at home depot, the one with the "plug in" wiring kind. I did not care for this plug in as it was a bit difficult to get it to set in place when I put the light onto the mount and made it difficult to tell if you had a solid connection. In any case, I got it installed ok and waited for it to get dark to test it out. Note that the circuit is from the sub panel in the garage (15 amp circuit) and is controlled by a 2 way switch. Anyways, when I went into the garage last night the first thing I noticed is that when I turned on the garage lights, they flickered. They would stop after a few seconds though. I went over to the new motion light and confirmed that the switch was "on", so I then confirmed the motion light worked, and it did. So I shut off the garage lights and turned them back on and once again they flickered. Suspecting the new light fixture, I shut off the 2 way switch that controls that, then again shut off the garage lights and turned them back on. They still flickered for a few seconds. At this point my son came into the garage and said the TV in the LR had gone off, and I went into the house at the main panel and found that the breaker controlling the outlets in the LR had tripped. It was a 20 amp breaker, one of AFCI breakers with a fault light on it. I reset it, went back outside and turned on the motion light, and the same breaker in the house tripped. I immediately disconnected the light fixture from its built in plug on the mount, and at that point I could turn on the garage lights without flickering. So I suspected either a faulty fixture, or more likely, that built in plug was not getting a nice tight connection, as its near impossible to tell as you have to fiddle around with it trying to blindly set it in while at the same time lining up the mounting holes. At this point I just wanted to return the light and get the old style kind where I wire nut together the connections, but as I was picking up, I noticed a burning smell at the electrical sub panel in the garage. The lights in the garage still worked, so the breaker was not toasted, but I obviously fear something sustained damage in that panel. I see nothing visibly burnt. Can a breaker put off that smell even if its still working? I could replace it myself, or I could bring in an electrician to take a closer inspection I guess. There are only a couple of breakers on the sub panel, so it would be no big deal to replace them. My bigger concern is why would that trip a specific breaker inside the house that is off the main panel? I did not observe any burning smell off the main panel, thankfully. do I have reason for concern here or would just having a less than solid connection at the light fixture cause all this?

 

What does that mean.That is what they call a 3-way switch in England. No such term in the U.S. Sorry I tried but without paragraphs or proper capitalization your post was just to hard to read.

 

I have no idea what type of light this is. Can you leave us a link for it at the Depot or a model number.

You had a branch breaker trip in the main panel inside the house but you smelled something burning in the sub panel in the garage ? I don't really see how the two are related.

 

they are definitely related, because as soon as the new motion light was turned on, the breaker for the LR outlets on the main panel was tripped. We tested it multiple times with the same results.

as for the question on a 2 way switch, maybe that's the wrong terminology, I'm just saying that the light is only controlled by a single pole switch by the door, there is no other switch involved like if I had the ability to turn on the light from more than one location.

and regarding the light, when I say its the plug in kind, I mean the mounting plate was a terminal connection block, so I take the incoming white and black wires from the circuit and they slide into a block that I tighten down with a screw (similar to the old electrical outlets). and then there is a ground screw where I wire nut that to the ground wire. so the light itself sits over the mount, and the male ends of the plug recess into the female plug on the mount, so its designed to be easy to use and more plug and play than the old style lights. The one I got from HD is Defiant 180-Degree 2-Head Outdoor White Flood Light-DFI-5936-WH - The Home Depot

 

Just to confirm you are saying the outdoor light is on the living room receptacle breaker. Is the breaker AFCI?Check that the ground wire isn't touching a hot.

 

no, the outdoor light is NOT on the LR receptacle breaker, which is why I am puzzled it tripped. The outside light is off its own circuit on the sub-panel.

I checked that the ground was not touching the hot, it was not. So I'm at a loss. at this point in time I would just like to know that if I smelled a burning smell at the sub panel, yet nothing looks melted or damaged, then what likely from that panel was causing the smell? keep in mine there are only 3 breakers inside the subpanel, so its easily to visibly inspect the wiring within it and it all looks sound. should I replace the circuit breaker despite that it still functions? would the circuit breaker put off a burning smell?

 

Tell us about the breaker that feeds the subpanel. Is the subpanel feed cable or conduit? Is it a 120/240 subpanel or 120 only?

 

the sub panel in the garage is a 100amp panel. The main panel in the house is a 200 amp panel. They connect via a cable feed. The garage is attached to the house so the feed is one of those heavy gauge gray cables that comes through the wall and down into the basement utility room where the main panel is installed. thank you

 

What size is the breaker in the main panel. What size is the cable? Is it 3-conductor plus ground.

 

the main panel has a 200amp breaker. I can't tell the gauge of the cable, but its quite thick. There are 3 big cables plus a ground wire coming out of the cable into the subpanel. 2 go to the main 100amp breaker, 1 goes to the right side and then the ground. It's also worth noting this is a new home construction as of 2012 so it should be up to latest code.

 

Actually those sound like wires in a cable. If the subpanel is more than six feet from the main panel it is suppose to be connected to a breaker in the main panel. Are you saying it isn't? If not how is it connected? http://www.doityourself.com/forum/li...rt-images.html

A picture of each of the panels with the front removed might help.