I have a 20 amp breaker that keeps tripping. I have replaced the breaker and that did not resolve the problem. The circuit was added after the house was built and the only thing on it is the sprinkler system timer and one of the large outdoor floodlights. I think it is a high pressure sodium light. The light has a photo cell, but it does not work. The breaker only trips when the light is left on for more than 48 hours and if the sprinkler system is turned on. I can leave one or the other on for an indefinite amount of time with no problems.

The sprinkler system uses a dc brick and pulls a very small load. I think it is something like 24 watts and 800 milliamps. I do not know what the light pulls.

Should I just split them up to different circuits, or do I have a different problem?