Cat6 + Low Voltage Wires (24Volts DC) underground


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Old 03-26-15, 09:39 PM
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Cat6 + Low Voltage Wires (24Volts DC) underground

Hello,
I am planning on digging a small relatively narrow low depth trench to lay down pvc conduit which will then carry cat6 ethernet cable and low voltage wires connecting a small solar panel array in my garage to the house and connecting both the house and the garage through ethernet cables.

Likely deeper around thepath there is a gas line connecting the garage to the house natural gas supply, so yeah I plan on being very careful; but this path is the short and straight path linking the garage to the house and also both ends of the path have cavities in the wall which then work as point of entrance for the cables and wires. So, I was wondering how deep would it be practical to dig mostly for aesthetic purposes (hide the cable and wires from view and protect them) and also to avoid any issues with the growth of the lawn (roots)?

Below is a pic depict some initial work done so far:

 
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Old 03-27-15, 02:18 AM
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It may not be required for low voltage, but 18" depth for conduit is the norm. I would not let it be any shallower, since surface activity can adversely affect buried items. Also unless the cat6 is rated as water resistant, I would be skeptical of burying it, even in conduit. You must plan on the conduit accepting water. Will you be using all the twisted pairs between the buildings? Will the sole purpose be carrying the 24 volts, or do you plan on signal use?

An aside, what is that plugged in the wall? If line voltage, it needs an "in use" bubble cover.
 
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Old 03-27-15, 05:48 AM
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What is the 24 volt power going to be used for? Low voltage is very susceptible to severe voltage drop if there is any significant distance and amperes draw.
 
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Old 03-27-15, 06:41 AM
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Low voltage cable like landscape light or TV cable is often run just under the sod, so a couple inches would probably be adequate. Electrical code if this was line voltage would put it at 18" minimum depth, but low voltage outdoors is unregulated. Until it gets warmer I don't think it's practical to dig any deeper than you already have. :-)
 
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Old 03-27-15, 10:59 AM
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Just to throw in my 2 cents, I wouldn't bury it any less than about 6". With freeze/thaw cycles, things buried shallow tend to 'float' up and it's definitely more difficult (and annoying) to bury it a second time.

And while burial-rated Cat6 cable is preferred, the cost of it is typically prohibitive, unless you can find somewhere who will sell you the 50 or 100' that you need. If it were me, I'd probably just bury typical PVC Cat6 cable, and plan on replacing it in 5-10 years when it degrades... at which point you'll probably want to run Cat10+ or whatever the new version is at that point.

-Mike
 
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Old 03-27-15, 05:54 PM
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chandler:

All right, I will aim at 18” deep trench before laying down the conduit. It is not a long trench: about 30 ft long, but some parts are difficult to dig due to a hard soil and rocks. 30 ft is long that long so I can also use any extra layer of protection on the cat6 cable, or even use external grade ones.
In reality I have a small solar array (about 400 watts) on my garage's roof (and small battery bank, etc), and I also have an equivalent small solar array on my house; both solar arrays will be expanded gradually. It turns out tha the solar array in my garage is often idle and thus generating excess of power which ends up underutilized, so the idea is to channel this power to the house in case it is needed: it is mostly a backup solution. And I can always step up the voltage to 48 volts (with minimum loss) to compensate for the resitance on the wires, but the length of the wires are not that long.

That peice of wire going into the wall is probably an old phone line wire. I haven't fished any wire yet, and I planing on using pvc conduit any for any underground and any exterior wire (weather sealed pvc boxes). Sorry about my ignorance, but what do you mean by the wire needing to be bubble covered?

Thanks!
 
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Old 03-27-15, 05:57 PM
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AlanJ:
Yep, I realize that. But the length of the wires will be fairly short (about 50 ft all in all), and I can always step up the voltage. I am not going to use higher gauge wires since the dist is relatively short; and it is mostly a back up solution (provide extra power to the battery bank at the house in case it is needed). Thanks!

ibpooks: I got the idea, I am trying to make it a little bit more permanent though, and maybe the use conduit to in the future to other things (maybe camera wires, etc). And since it is a short distance, I probably will go the extra mile and dig a little deeper. Thanks!


Zorfdt: yep, fraught not, I will dig deeper; I will aim at between 6” to 12”.If I can find a heap exterior grade cat6 I will use (since the distance is short, it may be cost effective); but sill I seall the pvc conduit really well! Thanks!
 

Last edited by tk3000; 03-27-15 at 06:13 PM.
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Old 03-27-15, 06:49 PM
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I think you should start over. 400 watts at 12 volts is 33 amperes, even at 48 volts it is more than 8 amperes. No way in the world are you going to transmit 8 amperes on any Category communications cable.

Also, do you have a FOUR conductor feeder to this detached garage? If you have only three conductors then you CANNOT have a separate metallic path between the house and the garage.
 
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Old 03-27-15, 10:28 PM
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400 watts only happen at high peak in production generating by the panels. Anyhow, I am not planning on using cat6 for power, I will have a separate low voltage wire going through the same pvc conduit to handle the power transfer.

There is a subpanel at a different place in the garage which is completely unrelated to my solar array and my data network.
 
 

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