Dedicated Tv / Flatscreen Circuits?

CNC

Dedicated Tv / flatscreen circuits?
Im adding some recepticles for a customer behind his new flat screen tvs, is it a common practice to dedicate these? its a brand new house, but its done, so its all remodel work, so i of course am fishing. So i know the circuits arent stingy as they would be on an older house, so if i have to juntion off existing plug circuits within the actual room the tv is in, i wont be concerened with the load.
IM just curious because of the fact that its a high end tv if its a good idea to dedicate? and if so what the reasons are? Basically i have heard for equpiment like this its nice to isolate a ground? which i dont know could be a load of BS. just seeing if anyone has some technical insight with this stuff.

do any of you use the recessed clock plugs for these types of tvs? for some more clearance?

randomkiller

I would do isolated ground to avoid electrical noise that may cause issues with hard drives etc. I always use the recess boxes that have the cable connections and recepticle adjacent to each other on opposing 45 deg angles, so it's all hiden behind the tv.

220/221

It's always a good idea to dedicate but it's not generally necessary.

GregS

If it's a large system that is going in, yes definately. 20A circuit just for the equipment, and a 15A circuit for the display is fine.

All the equipment goes through some power conditioners and battery backups, so the isolated ground may not be needed.

goose134

As stated earlier, some of larger screens will definately draw a lot op power. I once installed an 86" plasma that was around 1800 watts. Considering the investment that some of these TV's entail, it never a bad idea to put a TVSS receptacle on them.

mdshunk

I try to dedicate a circuit to the larger one's if the customer can fit it in the budget. Also, strongly consider using one of these new puppies for the receptacle set-up behind the TV. They're only about 20 bucks, from Arlington Industries:



http://www.aifittings.com/whnew98.htm

GregS

Or put a piece of 2" vac pipe behind the display to the basement or where ever is best for the components. No point in locking yourself in to a cabling type when it will all change again in 5 years.

randomkiller

That's a tad larger than the ones we get at work, I don't know the brand and of course I don't have one on the truck right now.

mdshunk

Yeah, Arlington makes smaller one's too. I just posted the biggest one for no special reason. They're still very helpful if all you want is the receptacle and an empty pipe to the basement or A/V closet. Note that the big one has lots of box knockouts for whatever you want to do. Here's a smaller one:

randomkiller

Never saw that little one, that would be great for refrig. outlets. I don't get into resi so unless we are doing a kitchen or bar in an office that is behind schedule I don't get into stuff like that.

mdshunk

Yeah, it's reminiscent of the old clock-hanger receptacles, but it takes whatever type of device you want to put in it. They make a 2-gang also, that has a low voltage barrier if you want to use it that way. I can see using the 2-gang for more wall-hung TV's than any other type. Receptacle in one half, and the empty low voltage pipe behind the other half. These are handy too (They take a regular Decora cover plate):

randomkiller

The last ones I put in were the same overall size (15 3/4") long as the one you showed with the knockouts but, all it had in it was a single gang for an outlet on one side and blank area about 4x4 on the other side with the small knockouts for modular (RJ/phono/coax) plugs.

kbsparky

Isolated ground receptacles are a waste of time/money if you are using NM cable and plastic boxes ....

CNC

Agreed.
I was just refering to isolating the gorund with a dedicated circuit. can someone ched some light on why in fact some electronics call for an isolated ground/ isolated ground recepticle? more for sensitive audio equipment and ground noise? what about video?

Neat stuff guys. Just the regular clock hanger recepticles will do also, right? easy to find, but they do have those annoying hooks, that are an eye sore if not being used.

Id like to stock up on a few of those box combinations, doubt my parts house has any. Any one mail order?

mdshunk

Just order them at your supply house. They pretty much all deal with Arlington now, and AI stuff ships really fast. You'd probably have it in a couple days.

goose134

IGR's are just like normal recepticles except for the lack of a connection between the yoke and the ground. This effectively removes the normal bond that you get by screwing an outlet to a metal box. The reason that they say they do this is because of 'electrical noise'. An EGC MUST be run to the receptacle in order for it to have a viable fault path to ground.
I believe NEC allows for the IGR's EGC to be terminated in a panelboard, but I could not confirm. Usually, an isolated ground bus is added, which is bonded to the building ground (at least in Chicago).