fishnfever

Go with # 10 wire and try to stagger the lights when you turn them on. Turn on 3 first and then add one maybe two after the first three are heated up. I know this sounds like a pain but this may be what you need to do if you want to run that set up.I would agree with the above post if you don't want to do it this way you could try using 300 wattinstead of the 500.

Gnwdad

I may be wrong, but I don't think there is an amp drop on those lights after start up (like the hps lights). It is going to be your amp draw kicking the breaker out. Buy the correct size SO cord for amps drawn and a 30 amp twist lock plug and it should fix your problem.

Here is a link for you:http://www.elec-toolbox.com/calculators/voltdrop.htm