PDA

View Full Version : Running low voltage in high voltage boxes



Ian Gills
08-12-2009, 01:23 PM
I want to run my cable and telephone lines into high voltage boxes, because I like how sturdy they are.

I know (for my wallet) I should use low voltage boxes.

Do you see any problems?

And no, I am not running electrical to these same boxes!

jbfan74
08-12-2009, 04:06 PM
Plastic or metal?
Plastic, No problem!
Metal, No problem!

Ian Gills
08-12-2009, 04:07 PM
Metal.

I love metal.

Thank you.

hj
08-13-2009, 06:38 PM
Boxes do not know, or care, what the voltages are. The wires you install are what is important. You can use 480 volt rated switching gear for your low voltage if you wanted to.

sixlashes
08-21-2009, 08:23 PM
If you are using metal boxes for low voltage (as I am currently doing), do you have to ground them? An electrician friend of mine is certain you must. I am not so sure. I have it on my list to research this in the NEC.

Does anyone have a para. reference?

ActionDave
08-21-2009, 10:40 PM
If you are using metal boxes for low voltage (as I am currently doing), do you have to ground them? An electrician friend of mine is certain you must. I am not so sure. I have it on my list to research this in the NEC.

Does anyone have a para. reference?

ask your eclectrician friend how he would do this or where he has done this. I'm curious.

sixlashes
08-21-2009, 11:27 PM
He says to pull a ground wire from the nearest (line voltage) box. Tomorrow, I will get into the book...

Cass
08-22-2009, 12:11 AM
NO...no can do...running low and high voltage in the same JB is not allowed...if your talking about just the box itself and all there will be is low voltage then I don't see a problem...

johnfrwhipple
08-22-2009, 06:29 AM
There is a lot of planning to pull off a great low voltage install.

You don't want to have your low voltage wire running beside line voltage as it creates a lower quality signal. That said you need to plan your routes carefully and if you need to cross paths isolated the area with wood blocking.

There are many extras you can buy for your low voltage wire and most extras snap into the pre-drilled holes of the low voltage boxes. If you like the look and feel of an old fashioned electrical panel box I would suggest installing it against some 5/8" ply so you can have a little wood to bite into to tie these wires down inside.

As for grounding the box you can do this many ways. You can buy a ground wire (#6 twisted strand - #14 coated) from your local store and attach the ground to your copper water lines (if acceptable in your area - check with your local town hall building department) and to the electrical box. If you are allowed to do this make sure you measure your pipe size and pick up the right piece to attache the wire to the pipe.


A better install is to buy a grounding plate and have that buried outside in the earth and the wire (usually #6) come up and into the house so your low voltage lines are grounded separate from your main panel. This step can be avoided if you surge protect the main electrical panel.

We have done many remodels with licencesed electrians and local building inspectors. My advice comes from my own research paired with first hand expeirence installing these items. Every town, city or district has there own codes and slight changes to local or nation codes. Take all your information down to the city hall and speak with the inspector and tell him/her what your plan is. My experience with the building inspectors is that they have so much on there plate they don't have time to tell everyone step by step how to do a job - but they can tell you if you plan to do ABC that A&C are right and to slightly change B and you are good to go.

Always pull a permit on your electrical work - If the laws are similiar in your town a home owner is aloud to do their own electrical on their home as long as it not a basement/nanny suite.

Jim Port
08-22-2009, 12:36 PM
The biggest reason not to use boxes has to do with maintaining the bend radius of the cables. The bend radius should be no tighter than a beer can or tennis ball. Use a LV ring and the extra cable has the whole stud bay.

Bonding of the LV cables should be done near the point of entry. They need to be tied to the house grounding system. There is a new NEC requirement to provide an intersystem bonding terminal for these additional systems. They should not just be grounded to an independant electrode or to cold water pipes.

ActionDave
08-22-2009, 07:27 PM
or a branch circut equipment ground.