Getting ready to install dedicated circuit

muncybob

A good friend is an electrician but certainly not an audiophile. I defer to him on most all things electrical in nature and I defer to the more experienced people here on most things audio. My bud is going to install a dedicated circuit for the audio rig. It's a failry short run from the breaker box to the outlet location of apprx. 20 feet. To do this right the first time what materials do I need?
At this point about all I have on my list is 12(or should it be 10?) ga. Romex, 20 amp breaker(read somehwere that I should consider a thermal magnetic type?) and a 20 amp outlet(hospital grade good enough?).
Anything I should do differently? After this I'll be looking for a decent conditioner with surge protection but 1 step at a time for now as I'm not sure how much the initial materials will cost me.

dkg999

I just ran two dedicated 20 amp circuits in the house I am renovating. One goes to a floor outlet box in the HT room, and the other goes to the room my 2 ch rig is in. I used 12 guage romex (10 guage is over-kill and very hard to work with in a standard wall box) and Hubbell hospital grade outlets. I did use standard SquareD 20 amp breakers.

ibewbrother

I will add that you don't really need a hospital grade receptacle. I would just go with a regular 20 amp. Unless you are doing something unusual like isolated ground, it's not really needed. I would also recommend going with a double duplex. I have a 15 bank conditioner, but I still found myself using the extra added outlet for lamps, I-pad charger, etc. If you are cutting a hole in the wall anyway...just make it a little bigger.

Good Luck

Brother

Journeyman Inside Wireman

Also...copper is insanely expensive right now...you might want to ask your friend if he can get some at contractor price... keep in mind though, 1 inch too short is too short.

bikerboy

You have short runs so make sure it will have more than you will ever need. Its easy to do at once and a pita to do it later. I wish I have one more circuit and it is almost impossible to add one now. For my two channel rig I would/should have one for digital, one for analog and one for the amps. Then make sure you have lights, ect. Good luck and it will make it sound better!

SCompRacer

Since your bud is an electrician he should know about proper box fill. (Box fill is the total volume of the conductors, devices, and fittings in a box). I've seen many DIY electrical jobs end up with box fill violations.

I used 12 gauge for my dedicated 20 amp two channel outlet. It is an 18 foot long run. I used a Hubbell Hospital grade outlet for durability as I also unplug my two channel system when not in use. (I had one lightning strike get into the house through wiring and was glad I do unplug it). I also went with isolated ground although the benefits can be debated.

drumminman

If it was me I'd get the best materials I could find as the bulk of the cost of this type of project is usually in labor. I'm guessing your friend is doing this gratis or for a nominal charge.

Never used this stuff before but for the amount you need the cost is only $60: cryo'd 10awg romex with ground wire, found here: http://www.vhaudio.com/wire.html

I've bought many times from Chris Venhaus, and he's a stand up guy with quality products.

I would also spend for quality outlets.

Polkie2009

I've been thinking about having an electrician install a dedicated 20 amp circuit in my den which is on the opposite side of the house as the breaker box,probably will need to run about 70 -100 ft. of 12awg romex. If I want to add another dedicated 20 amp circuit in the den, does this usually end up doubling the cost of one dedicated circuit?

playback

I have a 12awg and 10 and prefer the sound of the 10 ( more refined and smoother):cheesygrin:, get the ten or at least one line in 10awg so you wont be thinking about it later

SCompRacer

Polkie2009 wrote: »

I've been thinking about having an electrician install a dedicated 20 amp circuit in my den which is on the opposite side of the house as the breaker box,probably will need to run about 70 -100 ft. of 12awg romex. If I want to add another dedicated 20 amp circuit in the den, does this usually end up doubling the cost of one dedicated circuit?

You can run three or four wire romex. Three wire would give you two circuits with a shared ground. To share a ground, the two hots must be connected to opposite 120 input phases in your breaker panel. If the hots are connected to the same phase, you can/will overload the ground wire. If you don't want to share the ground, have them run four wire romex.

Polkie2009

Appreciate the info SCR! Ibewbrother mentioned above about using an isolated ground , would that be an advantage if part of the HT rig is plugging into the existing 15 amp circuit in the den?

SCompRacer

Polkie2009 wrote: »

Appreciate the info SCR! Ibewbrother mentioned above about using an isolated ground , would that be an advantage if part of the HT rig is plugging into the existing 15 amp circuit in the den?

Per wiki.

http://en.wikipedia.org/wiki/Isolated_ground

"Isolated ground means the use of a local ground connection with a supply, one of the common earthing arrangements used with domestic mains supplies.

The primary reason for the use of isolated grounds (IG) is to provide a noise-free ground return, separate from the equipment grounding (EG) return. The EG circuit includes all of the metal conduit, outlet boxes, and metal enclosures that contain the wiring and which must be grounded to provide a safe return path for any fault current that might occur. "

So an isolated ground means a separate ground wire run from the outlet ground lug all the way back into the breaker panel. IMO, it can be an advantage but depends on the quality of the existing electrical work. We have the NEC and local code, but that isn?t always followed or enforced. A typical example of what I have seen in new home construction. You have a romex run into a metal electrical box. A spring clip holds the ground wire to the box. It might be coated in wallboard mud and primer/paint spray.

The yoke (mounting straps) of a standard outlet are connected internally to the outlets ground lug. The installer didn?t run a ground wire from the outlet ground lug to the box. Your ground is now through the screws that hold the outlet yoke to the box (and they are sometimes loose to allow moving the cover plate around when it is installed to cover that odd sized hole around the outlet). The job has been inspected and passed. Yet you can have a poor ground circuit.

With conduit, what if the connections are loose? Or pulled out?

With an isolated ground outlet like my Hubbell, the mounting yoke is not attached to the ground lug of the outlet. You attach the ground wire directly to the outlet ground lug and that runs all the way to the breaker box where it is grounded. Or attach a short ground wire from the ground lug to the box ground if you are not using it as isolated ground.

So if the grounds were done properly (short ground wire from outlet to box ground) you may not get any advantage from an isolated ground. IG is one of them things that with the right people can turn into a CP cable discussion.:cheesygrin:

Polkie2009

Thanks for the well explained info SCR, very helpful.