check first what wires you have..turn the power circuit off and un screw the socket..you will see then that are they 1.5 2.5 or 3.5..
cos i had 670w before behind 2.5 core what is normal wire for lights..
and when i bought the wire the man in the electrical shop said thats it allright?
mayby he was right mayby he was wrong..but it did work for me..