We have a 20amp-120v ballasted lighting circuit that opens after 48 hrs of non continuous load. It operates 3 - 3.6 amp ballast's that are all in their range according to Advance, and they run through a 25 amp photocell. All fourescent sign lights are working & we have changed the breaker & phtotcell & one leaking ballast.
Thanks, Mike

Have you put an amprobe on the circuit to verify that 10.8A is in fact all you are drawing? Maybe there is something else on the line you don’t know about.

Nick,

Thanks for your input, we used a clamp on amprpobe and got just under 11amps total.

You may have to rent a recording ampmeter and check the loads. This way you can tell when the circuit peaks and trips the breaker which may give you some clues as to what is happening. I think GE Supply rents this kind of equipment.

My bet is one of the other 2 ballasts is going out. I would replace the other 2 now. I am assuming you have already replaced all 3 lamps.....

Thanks for your input.

I checked to make sure all that was on this line was the 3 ballasts. I isolated them and each draws 3.6 amps each.
The load has been continuous for 36 hrs now and the 20amp breaker is warm to the touch. 12 gauge wire to the panel.
Should we separate these signs and give them each their own circuit?
1 has 4- 10 foot HO lamps= 1 ballast.
1 has 10- 6 foot HO lamps= 1 ballast per 5.