Can I run power and RG6/CAT 5 in different conduits in same trench?

[potentz]

I am getting ready to run power to my shed and I also have my Satellite Dish and Internet Antenna mounted on the shed. The distance from the shed to the house is 100'. I am going to rent a ditch digger and was planning on digging a 18'' trench. I am going to run the 10-3 power wire in a 1'' conduit and I am going to run the RG6/CAT 5 in a separate 1'' conduit.

Question is, can I run both conduits in the same trench or will I still risk having interference with running parallel them in the same trench? One electrician told me I would be fine and another electrician told me to dig to seperate trenches 18'' apart from each other as the PVC pipe is not adequate enough to reduce the interference.

I don't mind digging another trench if that is necessary; however, I don't want to do if it is not necessary. Any help would be appreciated.

Thanks

 

[Gary S]

I put both of mine in the same trench. I made the trench wide enough so I could space the two conduits apart a few inches. I don't know how well this will work over the long haul, but so far I don't see any problems. I have my DSL line in the trench, and my video cables for my security cameras, and I'm not getting any interference from the AC so far.
Maybe if you have the time and energy, it might be best to dig two trenches, but I didn't get it done, so both of mine ended up in the same trench.

 

[Tscott]

Local code (FL.) states 12" horizontal separation, but this is for dig in protection mostly. The idea is to not hit one while digging for the other. You should see no interference as long as all neutrals are tight and you are well grounded. Remember, that these lines run together inside the walls of your home all the time without interference with each other.

My advice, dig a wide ditch and place power on one side and the other on the other.

Tom

 

[rieferman]

I also have both in the same ditch. 100 amps running underground in conduit, and the coax just buried directly (no conduit) a couple inches above. No issues at all.

 

[Cryptic1911]

should be no problem with interference.. rg6 is pretty well insulated, and cat5 should be fine as well.. although, if you haven't purchased the wire yet, get some cat6 as it has very tight winds, and its starting to become the new standard. You can buy rg6 and a 1000' box of cat6 relatively cheap from www.deepsurplus.com or www.monoprice.com

both are reputable, I buy from them regularly

 

[Costner]

I would have no issues running them in the same trench, but I'd separate the two conduits by about 6" for good measure. With a 100' run, you don't want to risk inductive interference caused by the low voltage wiring running in parallel with the line voltage for that distance.

While true these cables run together in many homes (because most electricians are far too lazy to separate them) they generally only run in parallel a few feet at a time and it would be extremely rare to see them together in a straight line for more than 30-40 feet. Ideally you separate AC line voltage from low voltage wiring by 18" of air space, but in conduit and separated by soil, 6" is more than sufficient.

By the way - if you can justify the cost you might want to run a spare conduit while you have the trencher. You just never know what you might want out there at a later date.

 

[malibu101]

FWIW- I have my electric serivice to the garage from the house in one conduit and another conduit carrying my coax, phone, and Cat6 from a router in the house. Both condiuts were put in the ditch side by side, probably touching each other. The run is about 80'. Everything works perfect. Picture on the TV is fine, no noise on the phone and the computer has no problems either.
My install is not correct in a perfect world, but in the real world it has worked fine for me for the last 13 years.

The 'puter has only been out there for less than a year. It sure was nice when I lucked into a good 'puter for out there and needed/wanted to connect it online, I tied a piece of Cat6 and a string onto the spare string I pulled through the conduit originally and yanked a data wire out there.
Everyone who says- throw in an extra/oversize conduit now, you'll be glad you did later is right. It sure helped me over 10 years after it's install.

 

[jdkenyon]

I ran power and cat5 for phone and network in the same trench. Total distance is around 130'. I put the power (100A service) about 24" down and all cat5 around 12" down. Everything is in conduit. So far I am not seeing any interference.

 

[potentz]

Thanks guys!! I am going to use some larger conduit with some LB covers and will leave a good nylon rope in the conduit incase I ever decide to pull anything additional through. I was going to use a separate LB cover for the power and the RG6/CAT5or6 to get into the house.

 

[royalton10]

For my 2 cents I would put in a conduit of 1.5 to 2" just in case for later on should electrical needs change. When I did trench to my garage 100' away, I put in a 1.5 for
electrical, 1 inch for phone; spare 1.5 inch for later on.

 

[ddawg16]

Costner pointed out the real issue with running them close together.....the 60Hz AC power is nothing to the 100Mhz+ of the coax...the real issue is the induced voltage on the shield of the coax and Cat 5/6. If not grounded, the shield can have 40-60 Vac on it....it's very low current so your not going to get shocked....but it could damage cheap electronics...

In the wall, the lines tend to cross at angles which pretty much eliminates any mutual inductance....but parallel to each other for 50' or more....it starts to add up.

So...since you going to have the ditching tool.....dig two ditches....

And I also concure on going up one size on the conduit.....I ran 3 #6's in a 3/4" conduit....only 30' but it was a tough pull....when I end up doing the addition to the house and moving my main panel, I'm going to increase the size to 1 1/4"....

One last piece of advise....leak check the pipes....mine gets water in it....I suspect the contractor who originally put in the pipe didn't even glue the joints.

 

[malibu101]

One last piece of advise....leak check the pipes....mine gets water in it....I suspect the contractor who originally put in the pipe didn't even glue the joints.

Not disagreeing but, I have seen many properly installed underground conduits (PVC and rigid steel). They mostly all get some water in. Not enough to ever run out of either end but when pulling new cables in or old ones out it is not uncommon to pull some water out. I believe condensation is the main cause, but that's only my guess.
I often come across/pull through concrete encased conduits for high voltage cables or critical data lines. They are like the day they were put in. All that comes out when pulling is the old pulling lube used when installed.

 

[walrus]

Their is water in every buried conduit I've ever seen, thats why you use wire thats rated to be in water. Conduits outside are a wet location

 

[Tscott]

x2 on what Malibu101 said. It's condensation that fills the conduits. There really is no way around it as far as I can tell. We just use a rat blower to push out the water if needed. It could also be rain water if one end of the conduit is exposed to the elements.

We actually had another local utility that was running conduit all the way to the top of their power poles for cable protection on underground services. They were not installing weather head on them. The problem came when it rained real hard and the 35' of conduit above grade fill with water. The lowest opening on the conduit was then at the customers meter base attached to their home. The pressure of the water was so great at times that water was laterally spraying out of the customers breaker panel. Needless to say, they no longer extend conduit more than 1' above grade at their poles.

Tom

 

[nate379]

The juice to the house and the phone line/internet are in the same trench for my place. No issues with it.

 

[Striker]

You can run dual conduit in the same trench, but it is advised to keep the two conduits separated by at least 12 inches. Low voltage wiring should always been in its own conduit. Additionally, while normal "indoor" low voltage wiring works, it is advisable to use underground rated cables.

As was previously mentioned water will get into the conduit. It's inevitable. With underground rated low voltage wiring the water won't hurt it at all. This is typically referred to as "outdoor" or "flooded" cable.

For coax I would recommend outdoor rated RG-6 quad shield cable with a solid copper core. Do not buy any coax that says "copper clad steel". This type of cable doesn't work very well due to voltage loss. It's worth spending the extra $10.00 or so for the spool. I'd recommend pulling a secondary/spare coax cable because you never know if you might need it down the road.

Networking wiring is a bit different. Cat 5e is the defacto standard now, but Cat6 is starting to replace it. Cat6 has a higher gauge of wiring since it is designed for better signal quality (ie less signal loss). Cat6 is a noticeably larger cable and can't be bent as well as Cat5e. Cat5e will still run a gigabit network just as well as Cat6 barring the wire distance isn't huge. You should be just fine with Cat5e, but you can spend the extra money for Cat6 to "future proof" yourself if you wish.

There are two types of network wiring which are solid and stranded. Solid is used for wire runs while stranded is better suited for patch cables. Stranded is a lot more flexible due to using copper strands. Solid is one solid piece of copper for each of the 8 wires in the cable. Both would work for you, but solid has better performance with longer runs. Furthermore there is "riser" and "plenum" grade of wiring. Without going into a lot of details, riser grade is perfect for home use.

My recommendation is outdoor flooded riser grade Cat5e cable. This should cost about $130.00 for a 1000ft box/spool due to the outdoor rating. Again, I'm recommending pulling spare Cat5e cables because they can be used for wiring alarm systems, phones, etc in the future.

I didn't mean to write a mini novel, but when it comes to low voltage wiring there is a lot of information out there and you deserve to know your options so you can make an informed choice.

 

[malibu101]

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I didn't mean to write a mini novel, but when it comes to low voltage wiring there is a lot of information out there and you deserve to know your options so you can make an informed choice.

Very informative post. It's right up with the now.
It is hard to keep up with technology (5E isn't that old and now 6 is almost a standard) and it's hard to look into the crystal ball and know what you will personally want or technology will be in the future.
No standing on a soapbox saying I'm right, I'm just saying PVC conduit is cheap so running a larger than needed or extra pipe is cheap insurance. 12 years ago when I ran conduits to the garage I never would have thought I'd wish for a network connection in the garage. Heck, back then I barely knew what a network was. After over a decade of laying in the ground without a thought, I'm glad I thought on the front end to allow for future expansion.

12 years from now I'll probably wish for a 100MB direct brain connection USB Cat99Z cable to the garage.
And I'll have the pipe to pull it through.

 

[1fastvx]

To add to this post, if you are running the network cable outdoors i would suggest lightning arrestors on both ends of the circuit.

John

 

[potentz]

John, what are lightning arrestors? Thanks

 

[1fastvx]

They protect you networking gear from lighting/voltage differentials. They should be used on any networking cable that is run outside. You can also opt to run fiber optic cable with media converters on both ends. That will keep you from bonding both building together with copper.

Here is one product:
http://metrix.net/cat-5-lightning-arrestor-p-23.html

John

 

[Metal-Marc]

... No issues at all.

In theory it is best to separate a few inches apart power and low voltage circuits. In practice sometimes there is no problem, and sometimes there are problems. It also depends a lot on the amount of power you are using in the garage/shed, etc. YMMV.