If the supply wire is 8 ga you should have no problem but MAKE SURE YOU HAVE THAT THING GROUNDED!! I always recommend enlisting the help of a pro who can look at this first hand just for safety sake. I am not saying I think you can't do this but to try and get advice from afar can be dangerous since it is all to easy to misunderstand unless one is there to look it over and with electricity being as unforgiving as it is the risk is too great. If you do it yourself please have someone with experience to look it over before turning on the power. If you have 8 ga wire coming from the breaker then you probably have a heavy breaker with the potential to cause some real damage if you make a mistake.