Outlets and Wire Gauge? - Please help!

@raysmtb1 I work in IT now. As a young man I worked for a motion picture audio company, and much later picked up what little I know of the NEC when I re-fitted a basement for woodworking. I purchased an actual textbook (not a DIY guide) and poured over the relevant sections. I’m sure others here understand the NEC better than I do by far, and certainly better than I do now, being decades away from what I learned, and the peculiarities of my state’s (Massachusetts) variations of it.

I just moved into a 17 year old house which was a rental for it’s entire life, so that sent me back to it again. It wasn’t terrible but after looking at what the home inspector tagged, the "haunted" lights and inspecting a couple of outlets I decided to overhaul all the outlets, switches and 120V breakers. Things have changed since my wood shop. In-panel surge protectors are now mandatory and CAFCI breakers are required in all 120V circuits in a home. Some outlets which were OK not to be GFCI’d now require it, and home outlets now have to be Tamper Resistant as well. Puts a damper on a lot of those boutique outlets people are buying. 😁

My Home Theater setup is attached to an isolated ground (ask your electrician). It helps prevent hum.

@erik_squires  I too am in MA, western MA.

@jimf421 My electrician mentioned my new runs being on isolated grounds.

Like Erik, I too am in IT but spent three summers in my youth renovating turn of the century houses where I had to replace all electrical and plumbing. My education was outside of books and for a man, who was a master in my eyes but I will never know if he was licensed or not. He owned all of the houses. I know nothing of the NEC.

@jimf421 

You don't need an isolated ground to prevent hum. What may prevent hum is ensuring all your equipment is wired to a ground that is at the same potential. Multiple separate outlets where the ground reference is 30 feet back at the electrical box is a way to get hum.

Better way to eliminate hum is to use balanced connections.

If you have balanced connections and you still have hum, you have a problem you missed. Bad equipment, a cable TV connection you forgot about, another load on the line making a lot of noise on the AC.

Ground loop hum is because ground currents are flowing in signal wires that should not be. For that to happen, there must be a difference in ground potential of the two pieces of equipment. An isolated ground does not help that as it must be connected back to the panel with your other ground. The new ground didn't fix the problem. Isolating the AC runs may have.