I do not know what
voltage we are working at exactly but when I
plug in an identical
fixture the issue is not replicated, it is just these two that have the problem I believe. Perhaps an issue with the cabling?
If you are plugging
in one identical
fixture, you aren't replicating the situation causing the problem. If you
plug in two identical fixtures, or unplug one of the fixtures from the
circuit and replace it with another identical
fixture, then you are replicating the situation.
Tripping the
circuit breaker results from one situation- overdraw of
power. This occurs either due to not adequately managing
power draws put on it, or an error in the
circuit such as incorrect
polarity in wiring or two one of the leads touching the
ground. Of course, if the
breaker is soft, meaning it no longer can allow as much
power to be drawn through it as it should before breaking the
circuit, it will trip prematurely.
Try what Derek said first. If one on causes no problem, good. If two on causes it, you know you are drawing too much
power.