Replies

1. 
   DaveRicheson | Apr 04, 2003 08:46am | #1

   The insulation on the cable should have some type of designation on it that will tell you what its rating application. If it doesn't, call the manufacture and they can tell you.  Look for a group of letters like THW, THN, THHN, and the list goes on. With those letters in hand,  it can be quickly looked up in the NEC book. Mine is at work, or I would look up low voltage wiring for you tonight.

   Dave

2. 
   pm22 | Apr 05, 2003 03:27am | #2

   I was hoping someone else would answer this question. It sounds like the evil Code section 725 may be involved here. [That's the section that goes on for four or five pages and never says what it's talking about.] Check your transformer and read the label. Does it say "Class 2"? If so, you might be entitled to some dubious priveledges.

   250 watts =~ 250 VoltAmps. 250 divided by 12 volts =~ 20 amps which would require a large wire - #12 or larger. Perhaps you could run it through a sleeve of concuit as it passes through the wall.

   ~Peter

1. 
   Jamie_Buxton | Apr 05, 2003 03:54am | #3

   PM22 ---  Yeah, this is big current.  The cable supplied by the lighting shop has a copper diameter equivalent to #8 AWG.  

   Rich --- This cable has no markings on it at all.   I think it is a knock-off of the Monster Cable used for loudspeakers.   That is, it doesn't seem to carry NEC rating.   NEC doesn't rate low-voltage stuff like speaker or thermostat cable, right?  Does it have a spec for 12 volt cable -- particularly high-current stuff like this?

2. 
   MajorWool | Apr 05, 2003 04:13am | #4

   I was leafing through sections 410 and 411 last night looking for stuff related to this question, specifically the issue of cabling going through the wall. But, the one unfortunate side effect of NEC is its potent narcolepsy inducing powers.

1. 
   4Lorn1 | Apr 05, 2003 04:23am | #5

   I second that vote. The NEC is a sure cure for insomnia. The only down side is that I end up dreaming about code problems. Not a restful nights sleep.

3. 
   househelper | Apr 05, 2003 06:10am | #6

   Look for cable that has two or more insulated conductors inside an outer sheathing that is riser rated. I use a 14ga sound and security cable for rated CL3R for low voltage wiring.