Outlets and Wire Gauge? - Please help!

The install was just completed and I am now afraid to connect my gear. Both my PS Audio PowerPlant 20 and Puritan Labs PM156 both say it is okay to connect to a 20A outlet, but the labels on the back of each read 12A Max and 15A, respectively. I have direct communication with each saying it is okay to do so.

Yes, it is. It's quite common, especially in the kitchen where 20 A circuits are run to multiple 15A outlets.  Of course, requires 12 gauge wire + 20A breaker, but this is absolutely routine.

The use of 20A circuits is recommended for multiple outlets, and sometimes required.  For instance, if your refrigerator is run on a circuit with other outlets that circuit should be 20A.

PS - When measuring voltage drop make sure you include the hot and neutral both. Meaning, for a 50’ 12 gauge Romex we expect ~ 3.2V drop per current carrying conductor, of which there are two: Hot and Neutral.

So the total effect of the voltage drop would be 6.4V total dropped (available) at the appliance, a little over 5%.

Assuming linear amps with unregulated supplies:

The lower the AC voltage the longer the recovery time for the amplifier storage capacitors, After an amp has been turned on and warmed up caps will only charge at the peak of the AC waveform so this becomes a bit of self-maintaining situation.

Whether or not it will affect your listening is another subject altogether, but personally I run all my gear after a Furman voltage regulator which keeps the incoming AC within 5 V at any point in time.  After my amp has turned on the biggest issues to my AC voltage are my heat pumps, oven and normal hourly variations in power supplied from the transformer.  My modest 100WPC integrated just doesn't stress the circuit very much.

Most other audio devices are fully regulated, and, with enough excess storage capacity, may never feel any difference between 100V and 130V.

Just want to get on my soap box here a little:

The best place for MOV surge protection is in your panel. Now required by the NEC, however they still have high let-through voltages. The NEC, and all major panel makers recommend you supplement them with point of use surge protectors.

Based on the Wirecutter testing, which AFAIK is the only reviews which include actual surge testing done in the past 10 years, the best are Furman and Trip Lite.

@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. 😁

@thespeakerdude

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 remember before arc fault protection came along that GFI was a ground fault breaker and that GFCI was a ground fault receptacle.

@evelyn1 The same feature (GFCI) is available in either a breaker or outlet. It’s more convenient as an outlet if you are in the kitchen and trip it. Dry your hands and reset the outlet. I use the term interchangeably and I think most do as well (see below).

It’s less useful to have a GFCI outlet for a fridge or range because you have to pull the unit out to get to it. 🤣 This is why GFCI breakers are convenient. However the behavior is 100% the same.

(PS - I just checked the Siemens site and they call them GFCI breakers too)

@thespeakerdude

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

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.

Pure series mode surge protectors like SurgeX and Brickwall are exceptions. Furman / Panamax with SMP uses a belt and suspenders approach though, so while they are mostly series mode, there is some shunting possible, and they need that ground.

Based on the latest testing I’ve seen however Furman and Tripp Lite have the lowest let-through voltages, not to mention a plethora of features so I continue to recommend them first.

Doesn’t afci/gfci refer to duplex receptacles that are used when there isn’t a ground wire present? You can buy them at Home Depot.

@evelyn1

They are 2 different types of protection. GFCI protects from shock, AFCI from fires, and the requirements are different.

GENERALLY speaking, GFCI is required near water (bathrooms, kitchens and outside) or to replace 2 prong outlets when a true ground isn’t present. The Ground Fault (GF of GFCI) happens when you become part of the electrical current pathway.

Arc Fault Circuit Interruptors, now upgraded to Combined AFCI (i.e. CAFCI), detect sparks that happen in the walls or junction boxes. While GFCI is required near anything wet, CAFCI is now required on ALL residential 120V circuits.

So, generally speaking, CAFCI gets implemented in breakers, GFCI on outlets, but there are combined breakers and outlets that do both.

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.

Historically, GFCI predates AFCI by decades, but the NEC has continued to expand the requirement for them. Now you may need GFCI on your range or refrigerator depending on where they are in your kitchen, and those are most convenient with GFCI breakers.

Of course, these requirements are only enforced with new construction and updates. You aren’t required to retrofit old circuits but you may.

You can’t back stab anything larger than 14 gauge. The holes are too small for anything bigger. You can back-wire, which is entirely different.

To be clear, back stabbed connections don’t use screws. They use spring loaded prongs which have a tendency to have poor connectivity and come lose. IMHO you should get rid of 100% of those from your home.

Back wired connections also use a straight in approach but the wire is clamped down by the force of the screw, and is held by two solid metal plates on either side. It IS a little more susceptible to losing it’s grip than wrap-around wiring, but a lot better than back stabbing.

Well, usually #10 is overkill, but your electrician is mistaken.  He is mistaking minimum required for maximum allowed. Here’s a listing from Lowe’s for a typical Commercial/Residential. Says clearly:

Convenient back and side wire connections allow for use with #10-#14 AWG solid or stranded wire

The Eaton website says the same thing. 15A outlets will take 10 gauge wiring but worthwhile checking on a case by case basis.