Dedicated circuits

A 15A breaker for an electrical outlet is anything but a 'robust power supply'. It's code minimum, regardless of the wire gauge.

You can plug numerous items into a 15A receptacle that exceed 15 amps, portable heaters come to mind. My Skilsaw. The outlet is undersized for the circuit, and the potential load(s).

That's incorrect. A 15A outlet shouldn't used on a 20A circuit.

immathew, that was my point. Or more properly, that the outlet should be sized correctly at 20A rating, not undersized at 15A.

In your case, with 15A breakers on 12 gauge wire, you haven't done anything unsafe, but you have placed an unnecessary restriction on your circuit.

jea48, thanks for all you do here on these threads, it’s appreciated.

As an aside, we had a job 10 years ago with in-floor heat, continuous cable laid under stone tile. The largest zone was apparently a bit too big, on a 20A breaker, and pulling a consistent 17-18 amps. The breaker would hold it for hours, but then finally trip.

jea48, my apologies, I left out one important detail. The heat cabling came in pre-configured lengths from the manufacturer, with factory terminations. The heat zone in question was the maximum length offered. The electricians knew their job, but in this case merely read the literature and provided the specified cable in the thermostat box. You can probably guess what the solution was.

Good call eliminating the stab connections. They're poor.