Tripping...the breaker

So I have been using a T5 setup since about Oct. 1. On the 31st I decided they were ready for some real light so I hooked up my 1k hps instead. Ran it all day Thur and all day Fri until about 9pm. I discovered a major light leak so I tried to swap back to the not so bright t5's until I a resolve the problem. Went to plug the t5's in and it tripped the breaker immediately. Never had an issue the month it was plugged in until I tried to switch back to it. Tried several times with same results so I did a quick fix on the light leak and plugged in the 1k again. No tripping of the breaker. Until now. Lights came on at noon fine, went to check on them about 1 and the breaker had been tripped. What happened? Nothing changed as far as I can tell. Only other thing running is an oscillating and has been since day 1. Need to get this solved, would like to flower soon and can't with an issue like this.

Overload...to many things on the circuit. are you in a older home?

Could have a breaker going bad, or you may have a loose connection in outlet itself, or bad outlet.

Try changing the breaker, maybe be worn out, check your outlet as nick88 suggested.

yep you either have a bad breaker or some power trying to run loose and the breaker is doing its job, make sure your not shorting out somewhere.

try running an extension cord from another outlet thats on the same breaker and see what happens, if it dosent pop the breaker then you know the breaker is good and its something in the outlet or past the outlet, could be something in your equipment as well but if it happened with both lights then chances are its not the lights, maybe the fan has a bad wire...

Thanks all for the input. I believe I have found the problem. There is a window unit that I didn't think was on the circuit, turns out it is. I have turned it off and reset the breaker. I will be checking it in an hour or so to see if everything is still on. Again, thanks for the responses.

Simple trouble shooting. Get everything off that circuit. Most outlets are on a 15 amp circuit.
Work backwards from your grow setup to your breaker.

I'm in an older home and used to have the breaker issue... problem was hidden junctions a previous owner had done, with the circuit stretching to outlets I never considered.

Do yourself and your family a favor and make it safe. The largest cost in new circuits is really the wire. Circuit breakers (110v 15AMP) are $10 and you can isolate your grow to a dedicated circuit. I've had 1K lights MELT the 110v AC outlet due to lose plugs/worn outlets. 1K lamps will be in the 9 to 10 amp range on 110volt leaving you a few amps to play with.

Check for heat, examine your cords, check the outlets... it needs to be safe. Consider dedicated circuits.