that's some old electrical wiring you;ve got there. you need 10 amps just for the hps and then more for the other lights, fans, etc.
read the amperage of the fuse for the circuit to your grow room. add up the amps from everything else on that circuit. if the total added amperage is lower than the fuse you are ok. if not, you need a new circuit or to move some of the devices to a different circuit.