Single Point Ground


I'm going to have a new room wired with two dedicated power circuits. I've read a single point ground is recommended. Can someone tell me if this is worth the effort and how it is done. I assume it is only important for the dedicated audio circuits.

thanks for any comments,

rogerdn
rogerdn
Rogerdn,

Isolated grounds?

If the gentleman was speaking of NEC approved branch circuit isolated equipment grounds, as used in commercial or hospital occupancies, then I assume he is talking about the use of isolated grounding type receptacles with insulated equipment grounding conductors.
Regardless, the equipment grounding conductor still has to terminate in the same panel the branch circuit is fed from.

Unless you are going to have the electrician install your two dedicated branch circuits in metallic conduit I see no need for using isolated grounding type receptacles.

If your electrician can use and install NM-B sheathed cable, (Romex is just one manufacture of NM-B), this is considered the best way to go. One cable for each dedicated branch circuit. Dedicated branch circuits only.... No shared neutral multi conductor separate circuit branch circuits!

If the distance from the panel to the outlets is less than 40' to 50' (12-2 with ground) would be ok. Over 50' I would recommend 10-2 W/grd. Many recommend 10 gauge period! One thing about if you install #10 now.... you won't wonder at a later date, what if......

Have the electrician use plastic rough-in boxes for the receptacles if at all possible.

Nylon flexible duplex cover plates.

At the electrical panel make sure the electrician connects the hot conductors of both branch circuits on the same Line, leg, in the panel. If he can on 20 amp breakers directly across from one another.

If you do have to use some type of metallic raceway, conduit, ask him if he can use MC aluminum armor cable.
Solid core copper only, three insulated conductors in each MC cable. Hot, neutral, and equipment grounding conductor. If he can, stick with the plastic receptacle rough-in boxes.

Your electrician not only has to follow NEC but AHJ (authority having jurisdiction) in your area.

Thks both of you for the detailed replies.

Jea48, pls clarify your comment 'If you do have to use some type of metallic raceway, conduit, ask him if he can use MC aluminum armor cable'. Would that be because of a Code requirement ?

If so I am not aware of any, pls confirm you are not recommending a metallic conduit unless required by code.

Is all NM-B sheathed or is there an unsheathed version ?
And what is the sheathing for ?

Is this different from regular cable I would buy at Home Depot ?
Jea48, pls clarify your comment 'If you do have to use some type of metallic raceway, conduit, ask him if he can use MC aluminum armor cable'. Would that be because of a Code requirement ?
Depending on the wiring method the electrician may have to use, he may not be able to use NM-B cable. Might be a (AHJ) issue. If he cannot use NM-B can he use MC cable?

My choice of aluminum armor MC instead of steel armor MC is only because aluminum is non ferrous. Has nothing to do with code.

Is all NM-B sheathed or is there an unsheathed version ?
And what is the sheathing for ?

Sheath only refers to the outer jacket of the NM-B cable.

One other thing I forgot to mention. Have the electrician cut in two separate openings in the wall for each rough-in box for the duplex recepts. Gives you more flexibility on down the road if you want to experiment with receptacle cover plates .

Like I said your electrician will know what needs to be done to meet NEC as well as (AHJ) for your area.

Make sure he goes over the entire job with you before he starts. Asks lots of questions. Make sure he is licensed....
Use 'Nylon flexible duplex cover plates'.

Why this recommendation Jea48 ?

thanks to all for the comments, this has been very helpful.