Outlets and Wire Gauge? - Please help!

Should note however that while GFCI’s are legal for 2 to 3 prong upgrades in old homes most surge protectors won’t work without a true ground. If you have expensive computers or home electronics and want surge protection you should get a ground installed.

@erik_squires, explain surge protection on a product with a 2 prong AC cord.

@erik_squires 

 

Typical MOV based surge protectors use the ground as a drain. At high surge voltages they attempt to short to ground and sometimes the neutral as well. Using a GFCI as a 2 to 3 pin adaptor won't create a magical ground path.  That is, there would be no ground to short to.

With any appliance the surge protector is trying to keep surges which (hopefully) are coming down the hot wire.  So, you have 600V suddenly on your hot. Where do you put it?  Neutral is 1 conductor, but having 2 conductors is better.  What if the surge happens on both neutral AND hot?  You need ground as your option.

A voltage, even a surge voltage, must be between two points. If all you have is line and neutral because you have a 2 prong plug, then those are the only wires the surge can come in on. If there is no other path to ground, than the ground connection of a surge protector can't help you.

Congrats man, you’ve just proven surge protectors can’t work. :) You are on your own now, and ignoring the fact that ground and neutral are bonded at the service entrance as well as basic MOV surge protection design. 

If you want to have those arguments you are on the wrong site.

I don't know why you are taking on an attitude. A surge protector will work just fine with a product using a 2 prong AC cord. It will protect against a surge voltage on line and neutral with which is the only surge voltage a product with a two prong plug can be damaged by, unless there is another path to ground. You are ignoring the basic principle that current or a surge cannot flow unless there is a path.  What does ground and neutral being bonded at the service entrance have to do with a 2 prong plug with no ground connection?

Typical MOV based surge protectors use the ground as a drain. At high surge voltages they attempt to short to ground and sometimes the neutral as well.

A typical MOV based surge protector will short the surge current to wherever the surge voltage exceeds the MOV rating. Line to Neutral. Line to Ground. Even Neutral to Ground. In commercial installations and outdoor installations, the wires are long enough that if there is a surge event, you can even get large voltage differentials between neutral and ground.

When we get speakers back and trace it to blown MOVs from a surge, it is almost always the MOV between line and neutral because the spike isn't from lighting, its from a generator or transformer failure and the surge current is carried on line and neutral.

@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.