Lights come on for about 3 seconds then shut off. Tripping breaker

[Happ1]

We tried temping up lights and certain sections that had emergencies stayed on while the sections wit no emergencies and straight regular lights stayed on for about 3 seconds then kiccd off. Im guessing its over amping. But they are 18 LED lights in each section. They are being tested using a 20amp 120 receptacle and extention cord. I have eliminated loose neutral or metal to metal since nothing pops.. what am i doing wrong

 

[gar]

171024-2208 EDT

The obvious first question is how much RMS current does one LED use. Multiply this by 18. Your time delay to trip implies a sustained overload on the breaker. If it was a GFCI breaker then it might the summation of many small leakage currents, because there is time-current trip characteristic in a GFCI.

Inrush current to the LEDs is very short, and if it was the cause, then you would not likely expect a trip delay of 3 seconds.

 

[James L]

Depending on how far from the panel the lights are, it could be a short on a fixture wire inside the makeup area

How many circuits are acting this way?
What do you mean you're testing them with an extension cord?

 

[Happ1]

171024-2208 EDT

The obvious first question is how much RMS current does one LED use. Multiply this by 18. Your time delay to trip implies a sustained overload on the breaker. If it was a GFCI breaker then it might the summation of many small leakage currents, because there is time-current trip characteristic in a GFCI.

Inrush current to the LEDs is very short, and if it was the cause, then you would not likely expect a trip delay of 3 seconds.

So we got .064 and multiplied that by 18 which is 1.152 we did that while we had the issue. I should have noted that Im at home at the moment. They tripped almost instantaneously while connected straight to a receptacle (even when splitting them in half)but certain sections remained on while testing them one at a time (one section is 18 lights) and adding a surge protector to the equation. Once we reached a certain section we had the problem i mentioned.

 

[Happ1]

Depending on how far from the panel the lights are, it could be a short on a fixture wire inside the makeup area

How many circuits are acting this way?
What do you mean you're testing them with an extension cord?

There are only two circuits in the area. They are split down the middle. So the area that is acting up is circuit 3, area for circuit 3 is 2 sections of 18 lights. Circuit 1 is working fine but once we get to that first area of circuit three we have this problem.. so what i mean by extention cord is we havent pulled in permanent wiring yet so we are testing the lights. There are 4 rows of 18 lights we test. We plug in an extention cord to 20 amp recep in the trailer. Which happens to be shared wit a mini fridge. And take the cut femal of an extention cord and pigtail it to the hot and neutral allowing us to get the lights tested

 

[Happ1]

171024-2208 EDT

The obvious first question is how much RMS current does one LED use. Multiply this by 18. Your time delay to trip implies a sustained overload on the breaker. If it was a GFCI breaker then it might the summation of many small leakage currents, because there is time-current trip characteristic in a GFCI.

Inrush current to the LEDs is very short, and if it was the cause, then you would not likely expect a trip delay of 3 seconds.

Could the mini fridge connected to the receptacle we are using to test be making the overload occur

 

[James L]

There are only two circuits in the area. They are split down the middle. So the area that is acting up is circuit 3, area for circuit 3 is 2 sections of 18 lights. Circuit 1 is working fine but once we get to that first area of circuit three we have this problem.. so what i mean by extention cord is we havent pulled in permanent wiring yet so we are testing the lights. There are 4 rows of 18 lights we test. We plug in an extention cord to 20 amp recep in the trailer. Which happens to be shared wit a mini fridge. And take the cut femal of an extention cord and pigtail it to the hot and neutral allowing us to get the lights tested

It sounds to me like you have 72 fixtures all together, four groups of 18, and that you're putting two groups on each circuit?

Three of these groups are acting fine, and one group is tripping the breaker?

If you're using the same extension cord plugged into the same receptacle to test all four of these, and all of your groups are the same quantity of 18, then it's not an overload.

If you were to add together the length of your circuit to that receptacle, the length of your extension cord, and the length of wire connecting all of the lighting in that group, are you looking at 200-250 feet, or more?

I still think you have a dead short somewhere. And the length of wire you have before you get there he's adding enough resistance to make it act like an overload.

Break that group of 18 in half, and hook up 9 and try that and then hook up the other nine and try that. if one group of nine works okay and the other group of nine trips the breaker, then you need to be looking for a short. Maybe a conductor nicked inside an MC cable, or a fixture wire pinched

 

[ptonsparky]

OP, is this a GFCI protected circuit? Ref to Gar’s post.

 

[Electric-Light]

OP, is this a GFCI protected circuit? Ref to Gar’s post.

You don't have two neutral paths do you? If any portion of current is diverted into another neutral path, the GFCI will trip.

 

[infinity]

So we got .064 and multiplied that by 18 which is 1.152 we did that while we had the issue. I should have noted that Im at home at the moment. They tripped almost instantaneously while connected straight to a receptacle (even when splitting them in half)but certain sections remained on while testing them one at a time (one section is 18 lights) and adding a surge protector to the equation. Once we reached a certain section we had the problem i mentioned.

Sounds like a faulty light to me. Nothing in your current calculation gets you close to tripping a 20 amp OCPD.

 

[kwired]

You don't have two neutral paths do you? If any portion of current is diverted into another neutral path, the GFCI will trip.

But should trip immediately and not after 3 seconds.

Capacitive leakage because of a long run could be an issue though.

 

[Sierrasparky]

This sounds like a job in California, and a project with a jobsite trailer so I would assume permitted. So I would be these have 0-10v dimming being under the energy code. I would bet that this is temped in using a GFCI receptacle. There is probably a issue with current flowing back on another neutral or through the dimming.