So, I had a friend wire my basement for me because even though I had a basic understanding of it, I wasn't 100% comfortable with doing it alone (he's been working construction for several years now). I noticed he wired a string of 8 outlets and then two can lights in the bar. He used 12 gauge wire for all the outlets but 14 gauge for the lights. All this is running on a 20 amp breaker. From what I've read, this is technically not code, but I'm not too concerned with that. I just want to know if it's safe. I also wanted to add an outlet to the circuit for under the bar for a mini fridge, so I'm thinking I need the 20 amp breaker for that reason, otherwise I'd just switch it to a 15 amp breaker. Any thoughts?
Not only is it "technically not code", it is not to code and could be dangerous. If you need a 20 amp breaker, then you have to change that wire to 12 AWG. It might be easier to run a new 20 Amp circuit to the bar and change the lighting circuit to a 15 Amp breaker although 8 outlets is a lot for a 15 Amp breaker. This is the kind of stuff that can kill a sale in the future or be a reason to insurance companies to drop you.
Giving your friend the benefit of the doubt, he may be misapplying exception 1 of 210.19(A)(4) exception 1a:
Exception No.1: Tap conductors shall have an ampacity sufficient for the load served. In addition, they shall have an ampacity of not less than 15 for circuits rated less than 40 amperes and not less than 20 for circuits rated at 40 or 50 amperes and only where these tap conductors supply any of the following loads: (a) Individual lampholders or luminaires (fixtures) with taps extending not longer than 450 mm (18 in.) beyond any portion of the lampholder or luminaire (fixture).
Basically this means you can use 14 AWG for pigtails for connecting light fixtures, when the light fixture is only rated for 15 amp or less, but those pigtails must be shorter than 18 inches. What your friend did, which was to use 14 AWG from an outlet or switch to the fixture, which almost surely exceeds 18 inches, is not allowed. If that 18 inches is exceeded the full requirements of 210.19(A)(1) must be met:
- General. Branch-circuit conductors shall have an ampacity not less than the maximum load to be served.
You should switch to a 15 amp breaker. And tell your friend he needs to review his material before he starts helping on other people's homes.
By the way, a mini-fridge could use a 6 amp breaker, if we even had that kind of thing in this country. Fridges are very small loads - stick a 'Kill-a-Watt' meter on one sometime.
Our own main fridge consumes 120 VA (1.0 amps) while it is running, and averages 36 watts (0.3A) on a continuous basis. I need just shy of 1.0 KWH per day to keep it going in an outage (which is important to battery sizing). We're talking a golf cart battery per day, more or less.
If you have anything important in that mini-fridge that would be hazardous if it spent time at room temperature, then I would have a dedicated circuit just for the fridge. You don't want a situation where the circuit trips, and later someone resets it because they need a different outlet to be hot, and never realizes the fridge was also on it and everything is full of bacteria now.
That also allows you to put bare minimum circuit protection (AFCI/GFCI) on it, to reduce the chance of a nuisance trip from those. Fridges don't really need GFCI protection, and on a dedicated fridge circuit, AFCI is fairly pointless if the cable is metal-armored.