im no electrician but it depends of wires as well...
example...
5-6years ago my grannys houe we got electrician to wire up a new cooker and when everithing was done and he turn the cooker on HE BLOWED THE FUSEBOX...becose house was old and they were aluminium wires...they are the most useless things ever...so end of the they we had to spend prob round 5000e to get full house re wired.just to be in the safe side...

best things for you would go some electricians or DIY forums...
good luck with your grow:thumbsup: