Disclaimer: Electrical work can be very dangerous! I did this with nothing more than my wits and a few books on electricity. Only do this project if you are familiar with electrical safety! I take no responsibility for any electrical shocks, fire, or damaged equipment. 30 amps of 220v power is enough to cause serious injury and even death. That being said, Ive run two of these at maximum capacity for the better part of year with no problems.
Not to mention in America it's required that you get a permit and have a license electrician do the work, this was if there is ever an electrical fire in your house due to your lack of getting a permit from the city and hiring an electrician your insurance company will walk away as they are not required by law to fix your house if you didn't follow the by-laws.
I knew someone who did this and suffered dearly when their wiring shorted out causing a major fire. Once the fire marshal determined it was an electrical fire due to improper wiring the insurance company asked the home owner to see the permits on the house, when the saw there were no permits they walked away leaving the home owner empty handed and having to fix/rebuild their home.
from my understanding homeowners CAN do their own wiring..if you have an electrical inspector come and check it and he signs off on it (50 buck) no problems...and most would be nice enough to tell you what was broke allow you to fix it and check again (at least in my experience)
but yeah if you skipped the part about being inspected....but then again ANY inspection by an inspector of your work (or even if you had added an extra circuit or two later that caused probs) how would they tell the inspector that looked at my bsmt when the panel was changed...he just went around looked at the ceiling boxes all looked well and that was it..only glanced up with the eyeball only opened the panel to look all else was a glance
anyway safe bet is to just do the wiring look on ...youtube or some friends with experience skills can help ...get it inspected ..if it is ok you saved a few bucks if not he will tell you what is wrong...worse case you can just get an electrician
anyway from my experiences....to be safe just get an electrician if nothing else he or the inspector may find OTHER REAL PROBLEMS that have nothing to do with your additional stuff...that would be safest
again just from my experiences re-wiring knob and tube wires in my basement mainly and house
then again anything is better then 1920 wires so maybe he was just pleased at that!