Later this week I will be going on in inspection to a home that I already know has a situation I am not familar with. The older part of the home has the old fuse panels, main power for the home and lights. The furnace/AC, hot water heater, W/D are all on a new breaker box. My question is this..can u use both within the same house? Sorry no photos yet...if needed I can have some here Thursday night. thanks for any input.