can you have to much power

i have a problem. i set up some power for a friend. he wanted enough power for 3 600w lamps. so i go a 30amp breaker but he didnt have any space for a new breaker but he did have a 50amp breaker that wasnt in use. so i ran the power throw that. when we pluged in a fan to test if there was power the fan seemed to be moving a lot faster then it usually does. i was wondering if the 50amp breaker is to big. and if it is save to run the balasts on the outlit that its hooked up to

If there is a malfunction, it will draw more power to trip the 50. They sell double polls that equal 30, 15+15 that should fit were the 50 is. 15 amp will handle 1800 watt indefinetly. But like you said if you got a fan etc.. 30 would be better. imo

IS the house wire that goes to that 50 amp circuit the correct guage wire? It would have to be heavier wire then the standard wire for 15,20, or 30 amp usage.It has to be able to handle the 50 amp load and if its not heavy enough it can easily cause a fire

i bet what was going on was that the fan was normally on a circuit that has a lot of other stuff so there was less voltage, even 2-3 volts will be noticable, but yeah, if the house is old i would go ahead and toss the 50 amp and install a new one with proper size wires of course, the fact that its a 50 amp is not a danger, i mean if you think about it say you only have one small light on in your house and its on a 20 there is no danger, if you do decide to run the 50 just make sure you have the proper size wire so if there was a problem the wire would not fry before the breaker tripped