Re: building codes.
Not sure if this is his particular issue, but let me tell a story.
I knew a guy who wanted to run an outlet to plug in a lamp. That’s it a simple lamp. He went to the store. He bought an outlet. He bought a 15 amp breaker. He bought 18-gauge wire. Installed the breaker and ran the wire to the new outlet. Burned half the house down.
When running a 15 amp circuit, BUILDING CODE in the US requires the use of at least 14-gauge wire (18-gauge being less than half the diameter), because that’s how big the wire has to be at minimum to properly dissipate the heat should that 15 amps actually be drawn for any reason. Basically, the breaker is supposed to always be the weakest point, not because some dumbass made a rule, but because then the breaker trips and cuts off the current, so the wire doesn’t overheat and start flaming up everywhere, and burn your house down.
Those other building codes? Yeah, they have similar reasons.