MOAB is awesome. I have been using it and getting huge blooms and flowers with it. It is actually good to use it all the way through the bloom cycle with a constant ramp up.
you need to locate the breaker box and see how many AMPS each breaker, and the MAIN BREAKER are rated for. 20amps will keep things moving nicely. But you should Always consult a professional electrician believe me it is worth it.