Electrical question... UF inside walls?

[Inspector507]

Richard, as far as to your question.....UF inside walls?
Yes you can, according to the 2008 NEC. NEC Article 340 covers Type UF cable. Article 340.10(4) reads.......
Installed as nonmetallic-sheathed cable. Where so installed, the installation and conductor requirements shall comply with Parts II and III of Article 334 and shall be of the multiconductor type.

Parts II and III are Installation and Construction Specifications. Both UF and NM cable conductors are required to be 90ｰC rated. However they can only be used at their 60ｰC ampacity. In certain cases where installed in contact with thermal insulation, ampacity adjustments may need to be applied.

 

[eepete]

@kenstrac: Indeed my problem was that the big box store UF was 60 degree C. The cable you had specs for would be fine. My inspector didn't care about the box external to the can lights as far as temperature rating. Don't know if that's right or wrong, but it does say to me that if you can bounce something off the inspector before hand it could avoid a fun discussion about interpreting the code.

@Richard: When I did my theatre, I just made sure all power for everything was on the same phase (side of the 240) and nothing else was on the circuit(s). Some of this comes down to your equipment too. My amps had an RCA connector on them, but it was actually a differential input so hum was not a problem.
I made the mistake of putting the amps close to the speakers. That means I had too much high end role off on the wire going from the preamp/processor to the amp. I should have put the amps close to the preamp/processor and then run whatever it took to get to the speakers. I refuse to get into any discussion about audio wire, but for me I'd be happy with simple 12 gauge wire to the speakers. Bi-amp to the speakers is good. Again for me, the #1 consideration in low level (non speaker wire) is the capacitance of the cable. The 12 gauge romex type wire has low capacitance and at 4 or 8 ohms, the roll off you get will be small compared to the acoustics of the room. Your 12g outdoor low voltage wire will be great.
Finally, if you can put all your equipment in one place and it's on the same circuit or branch, you'll have very few hum problems. That location is the hub of your radial ground system, and this is another good reason to have the amps together and make the speaker wire runs long. The axel of the hub is the preamp or processors, since everything plugs into it. Isolation transformers are for isolation AC circuits and not for providing isolation over the entire audio range at the 60-80 dBV level. Anything in a house with electronics should be plugged into a surge suppressing plug strip.
Subwoofers are different. Because they are low frequency devices, you _can_ run the low level lines to them. It is, however, important that they be on the same circuit (preferable) or same side of the 240. Assumption here is that you have a powered subwoofer. You will also need to play with the position in the room.

Pete

 

[dmccarty]

Richard,

Run some Cat5/6 cable to the receiver location. I put Cat 5 all over our house. But for some daft reasons I did NOT put an outlet near the TV/audio equipment. There are not one but two coax runs to that location but for some reason I did not drop Cat 5. I might have to pull the wire up that wall some day since everything is going digital. We might get away with using wireless but I would rather use Cat 5.

Later,
Dan

 

[eepete]

One could almost start a new thread on home theatre / tv room wiring...

I put 2.5" conduit up to where the TV would be, 1.5" where the speakers would be, and another 2.5" up by where people sit. Don't forget conduit or wires for the rear speakers too. You can order long HDMI cables on the internet for much less than they cost at a electronics box store, and this will fit up the 2.5" conduit. I've had no problems with a 40' HDMI cable. Some of this is influenced by the fact that I hate to look at the equipment. I either want it of to the side (for DVD player), or hidden in the basement (for everything else). Assumption here is that you'd have access to all this on the floor below. By design, I put the area below the TV room as the central area where all the low voltage stuff gets pulled.

If you want to put everything up front, then bring the 2.5" conduit out where you'll hang the TV on the wall, and then at outlet level put an access box. Continue the conduit down into the basement. That still gives you the "floating in space" look for the TV and speakers, but lets you connect up your stuff. As per dmccarty, you'll still want cat5's and RG6's coming up your equipment location.

Yell if you want more ideas, as I'm sure everyone has figured out I'm not shy about typing...

If you can't be right be flexible. And I'm wrong more than I'm right.

Pete

 

[Richard]

Sorry that I abandoned for a while. I'm back

General comments to the above general comments:

1. I've removed all the UF. I couldn't find (see ) the temp rating and had 3 spools of 250' 12-2 w/g so figured I may as well put in what is typical.

Regarding HT wiring... wow...it's a line of wires going across the room.

I have three drops in the front of the room. For each location (left center and right) I have:

2 sets of speaker wire (4 strands) 12g
1 pair of Canare star shield or somethign like that, for a long run of RCA
1 pair (yet to be installed) of Canare or Mogami for 2 XLR jacks
1 pair RG6 cables
1 pair of Cat6 wires

In addition to the above, my center channel location has FOUR runs of Cat6.

Regarding HDMI... I've been told (and started a thread elsewhere that I could find/reference) that HDMI is evolving to where you must be compliant with their requirements or they can prevent you from getting full use of it.

Meaning.... as I've been told, if you go out and buy a Blue Ray DVD, that DVD will have some encryption already built into it that can program your hadware. The hardware on both ends can communicate in each direction with each other and must pass a handshake. Once they do this then all is well. If this handshake fails then you might be stuck at the lowest resolution possible.

Also, I think I understand that HD signals won't be allowed to go over analog wires (component?) after about 12 more months.

Cable length is reported to be an issue on HDMI cables in some areas...and in other areas, cable length does not seem to be a concern. Sort of depends on who you talk to.

I've been told that as this evolves, the HDMI will be doing more and more so the length will become an issue if not already.

My solution? I need about a 45/50' run to go up/down the walls and to traverse the room. Seems you can send HDMI signals over Cat 6 wires for MUCH longer distances.

I'm going to install two HDMI 1.4's if I can find them in 50' length. If that ever quits (or I drive a finish nail through it ) I've got my Cat 6 in there as a backup. Seems it takes TWO runs of Cat 6 to get full use of HDMI so I've got two, double runs to be sure I'll have enough.

For people who are NOT burying their wires in the wall, this clearly isn't an issue. You can always yank the cord & put a new one in. Since I'm burying inside my walls, I am trying to look out as far as I can to get it right upfront.

Regarding conduit.... My firring strips are 2x4's turned sideways so my walls only have 1 1/2" to play with. I also like the idea of adding some conduit but think that is going to limit me to some degree. Anything that has an end on it, might be problematic going through 3/4 or 1" conduit?