Different versions of the national electric code have gone through revisions that might allow 14-3 for 20A. You would probably have to check with your building department which version they have adopted. Also, if your contractor used 75°C wiring throughout, they might be fine.

Having said that, the cost difference between 14 and 12 gauge really isn't that much over the entire project. This is extreme penny pinching and it can cause difficulties down the line, if you can't get a new building permit from your city until you rewire your house (because they changed their mind on whether this is acceptable). Or if your insurance company refuses to give you a policy until they can verify in your breaker panel that all 20A breakers have 12 gauge wires.

Have him fix it now before you are fully moved in, when these changes are much harder to make.

Also, you really don't want anything other than the fridge on that circuit. Breakers do trip. And I certainly have managed to trip my breaker with my microwave before. If that goes unnoticed, all your food could spoil. What a pain.

Yes, I would fight this. Builders always cut corners, and as a home owner you'll have to deal with the outfall of those decisions for years to come. Don't let them get away with it, when it is this easy to notice.

Thank you for your reply. I’m just concerned that neither Outlet is gfci (which I wouldn’t want the fridge on) and incase the draw were to exceed the wire limit from surges or failed appliances it would melt the wire. It’s in Wisconsin and they follow NEC 2017 I believe.

but I do plan on fighting this, because I thought the same with the low cost difference between 12-3 and 14-3 wire. Just getting others confirmation

"Building codes based on the National Electrical Code prohibit the use of 14-gauge wire anywhere on a 20-amp circuit. All wiring in such circuits must be 12-gauge or larger." -- SFGate

If you wouldn’t mind giving you opinion on another issue. there Are 2 20 amp circuits for The kitchen. one for each wall. And at the start of each run is a gfci outlet. my concern is with circuit B is that it’s a tad annoying that they have the floor dining receptacles tied with the ones on the counter. So if there is a fault in any one of them, it trips all of them. Is this code? Sorry for the poor drawing.

If you wouldn’t mind giving you opinion on another issue. there Are 2 20 amp circuits for The kitchen. one for each wall. And at the start of each run is a gfci outlet. my concern is with circuit B is that it’s a tad annoying that they have the floor dining receptacles tied with the ones on the counter. So if there is a fault in any one of them, it trips all of them. Is this code? Sorry for the poor drawing.

Point them at 310.15(b)(16) in the NEC. For 2017, you can find an (inofficial) excerpt at https://www.lapptannehill.com/pub/media/wysiwyg/pdf/AmpacityChart.pdf That should answer the question about wire gauges.

The rest of the wiring sounds OK to me. But don't take my word for it. I am no expert at reading the code.

As far as chaining GFCI outlets, I believe that is legal, even if it might be nuisance to the homeowner (and I think it requires labeling). But this is super easy to fix after the fact. Buy a couple of GFCI outlets. They are not that expensive, and replace the regular outlets. Don't forget to rewire the existing GFCI outlet so that it no longer daisy chains into the new outlets. The only thing you need to watch here is that this is an all or nothing deal. You shouldn't leave any unprotected outlets.

This should cost less than $100 in materials, even if somebody overcharges for parts.

20A circuits require 12 gauge wire. You can't put 14 gauge wire on a 20A circuit.

(Don't just look at the table in the previously linked pdf. Read the * note at the bottom of the table)

I'm not a code guru, but I believe that counter top receptacles can share their circuit with other areas related to the kitchen, so the dining room receptacles are probably fine. But I don't think the outdoor receptacle is allowed to be on that circuit. Hopefully someone else who is more familiar with the code will chime in and clarify that.

Is the house finished and has it already 'passed' inspection? Don't depend on an inspector to actually catch all the problems. Some inspectors don't even do an inspection. They just know a builder and trust that they did a good enough job and pass it and then go and have a 5 hour lunch.

Let your builder know that you'll be paying for an independent inspection and you'll raise these concerns with that person. He may suddenly remember that it might be a good idea to change these things that 'aren't really an issue'.

Thank you everyone for all your input. Unfortunately the upstairs is all finished but the basement is not And the floor trusses are wide open. So you can see where they ran all the wire.

I will be sure to note the above code refer poll reference. Yes it has already been inspected and passed but I like the idea of another inspection by an independent person.

If you are unable to get a second electrician's site visit, then familiarize yourself with practicing electricians' free advice on SABC's (Small Appliance Branch Circuits). Here's just to get you started:

Dining Room SABC

Thank you very much for that. I appreciate the help

So, last question. Isn’t it code as of NEC 2017 (which Wisconsin uses) that the microwave and fridge need to be on a 20 amp circuit? they were telling me that it is code to be 15amp so they don’t have to run new wire

I'm not sure what the code says, but from a practical standpoint, the microwave should be a 20A circuit because otherwise that will limit what microwave you can buy. Some require a 20A circuit because they can be big power draws.

I think the fridge would be fine on 15A.

But ultimately, you really should get your own inspector. You can't trust anything this builder tells you and the code can be a complicated thing to understand. You need someone with authority to be able to push back against your builder.

that was my thoughts too.

thank you @greg_2015 for your help. i have an independent inspector scheduled for next week.

There hasn't been any code out there (at least not in the past 40 years) that permits NM 14g cable to be protected by a 20A breaker.

I've never seen a countertop microwave with a 20A plug on it. Most of the monster "speedcookers" require hardwired 20A circuits.

Never seen a fridge need more than 15A either. The code allows a dedicated fridge circuit to be 15A as well under an exception.

You have a couple threads on the same thing goin on. www.houzz.com/discussions/6084029/nec-2017-electrical-question

Here's your NEC 2017 codes abbreviated to your questions, check local AHJ for amendments:

210.11(C)(1) - kitchen requires min (2) separate 20amp SABC

210.52(B)(1) - those (2+) 20amp SABC circuits shall supply receptacles for the kitchen, pantry, breakfast, dining, or similar areas, including all counter and refrigeration.

210.52(B)(1) Exception 2 - a specific appliance can be served by a separate min 15amp branch circuit (e.g. dishwasher, microwave, or refrigerator)

210.52(B)(2) - any of the (2+) SABCs cannot serve other areas not defined in 210.52(B)(1) or other outlets (e.g. lights)

210.52(B)(2) Exception 2 - those (2+) SABCs can power supplemental gas-fired equipment

210.52(B)(3) - kitchen specifically can have more than (2) SABCs, and can also extend to areas listed in 210.52(B)(1)

210.52(C) - dimensional and placement location of those receptacles required in 210.52(B)(1)

240.4(D)(3) - overcurrent protection device (your breaker) shall not exceed 15amp for 14ga copper.

240.4(D)(5) - overcurrent protection device (your breaker) shall not exceed 20amp for 12ga copper.