DUX COMPUTER DIGEST

 

Site Search

Site Info

Home » Forums » Forum Archives » Networking and Internet Sharing » Topic # 1719

CAT-5 OUTSIDE
jb4home Feb-21-02 12:25 PM
Hi--
New to this forum...
read all the FAQ's on the subject - but considering it's last update-
I figured asking again...maybe there are some new ideas out there...
"Running Network Cable Outside of a Building - Last updated: 9/29/2000"

Situation:
Garage in not connected to house.
Have a workshop + small office there.
Approx 50 feet distance.
Currently there is a buried 1" plastic outdoor "PVC" pipe linking the two buildings
for electric power. There is an outdoor romex line running thru the pipe to the garage.
(the power cable is a sealed cable within the plastic pipe... NOT 2 or 3 loose wires - for extra protection against the elements)

Anyway-
What is today's (2002) ability to run either:
1. Inside existing plastic pipe a CAT5e cable line (shielded??) (noise with 110 electric??)
2. Run a new similar plastic pipe to house the CAT5e cable on it's own

Lightning Danger inside Plastic - ??
Plastic pipe runs out of main building 18" above ground and then is buried...
...comes out of ground about 18" again and re-enters garage.
Tks
jb


1. RE: CAT-5 OUTSIDE
lbyard Feb-21-02 12:51 PM
In response to message 0
>1. Inside existing plastic pipe a CAT5e cable line (shielded??) (noise with 110 electric??)

Shielded might work. I would probably try it, perhaps with jell-filled cable. If the cable costs a lot, I would look into installing 110 punch-down blocks or jacks at cable entry points and running unshielded inside.

I doubt very much that unshielded would work.

>2. Run a new similar plastic pipe to house the CAT5e cable on it's own

This would probably be better, but expensive.

>Plastic pipe runs out of main building 18" above ground and then is buried...
...comes out of ground about 18" again and re-enters garage.

You almost have a circuit (short jump) between the ground and any high point on the line in the building. However, you also should have a ground wire in the power line. I don’t think the 18” is a problem, but any network cable that you run in either building could attract a strike at a high point. That doesn’t appear any more dangerous than other wires in either building, but I am not sure. It has to be safer than running wires above ground outside of the buildings. Do any this at your own risk. Larry


2. RE: CAT-5 OUTSIDE
rabnud Feb-22-02 09:32 AM
In response to message 0
Biggest items I can think of:

1] Moisture in the pipe will most likely kill regular cat5 transmission speeds, you'd need direct burial rated cable (www.syndat.com says direct burial cable exists as "763108 - Helix Category 5 Direct Burial - Black"). I've heard of telco lines run underground which are frequently ventilated or otherwise dried out to improve a degrading signal conditions, due to moisture contacting the cables. The direct burial cable is likely designed for this.

2] Electrical noise gets coupled from powerline, despite the cat5 shielding.

Remember that normal runs of cat 5 would be allowed to randomly wander away from the power cable, when it is run in, for example, an 8 foot tall wall or along 30 feet of crawlspace. Your 50 feet of 1" pipe will ensure that the cat 5 won't get very far away from that power wire, and this close proximity may reduce shielding effectiveness. Ask a pro cable installer about this coupling effect; and also ask about coupling at a cable television installer or supplier, if you dare! They know it can happen with shielded cables, and will wonder why you ask.

Your workshop implies motors, possibly brush type motors (dremels, hand drills). I think your condition (the forced mechanical proximity and "noisiest possible" neighbor) is the worst possible electrical environment for any data cable.

3] I'm in New Hampshire, being as it is presently mid-winter, frost is rampant. 50 feet is a long underground run, frost movement is very likely. If that pipe ever mechanically shifts, as in frost induced shifts, you might pinch the data cable into the power cable... AC line power conductors meet low voltage data conductors. Pow! Exploded NICs (at best).

I may be overly pessimistic, but don't forget that any water in the cable would *mechanically* degrade the shield: aluminum foil shield vs water means galvanic corrosion and thus shield degradation over time. How quickly? Don't know.
Also, the moisture in the pipe isn't exactly pure, the pipe isn't necessarily intact, the ground isn't necessarily unfreezable, etc., so there may be contaminants in the trapped liquid which would further corrode the individual wires themselves, once the jacket gets compromised.

To me, the end result is don't try it, unless you feel that the risks are acceptable. Your mileage may vary.

I'd consider RF wireless data connections, or possibly fiber optics in that pipe: nothing is conductive in the fiber cabes I've heard of (but you need to check them out first), thus without metals you eliminates the corrosion and short circuit angles I mentioned. Then, if water degrades the cables' optical properties or if the frost pinches it, simple data loss is all that will result.

That's my thirteen cents.


3. RE: CAT-5 OUTSIDE
lbyard Feb-22-02 12:22 PM
In response to message 2
>1] Moisture in the pipe will most likely kill regular cat5 transmission speeds, you'd need direct burial rated cable (www.syndat.com says direct burial cable exists as "763108 - Helix Category 5 Direct Burial - Black"). I've heard of telco lines run underground which are frequently ventilated or otherwise dried out to improve a degrading signal conditions, due to moisture contacting the cables. The direct burial cable is likely designed for this.
Yes, it can be a problem. Back in the old days we used to pressurize the lines with nitrogen. I can’t remember the frequency, but we often made the landline run going from manhole to manhole taking pressure readings. I think jell-filled cable is supposed to do the same thing, except it doesn’t leek.
> 2] Electrical noise gets coupled from powerline, despite the cat5 shielding.
Theoretically, shielded cable will block all interference—theoretically(!). I think I would still try it. If it doesn’t work, pull the cable and start digging. I would first, however, seek more advice as recommended.
>Your workshop implies motors, possibly brush type motors (dremels, hand drills). I think your condition (the forced mechanical proximity and "noisiest possible" neighbor) is the worst possible electrical environment for any data cable.
Arc welders are worse.
>3] I'm in New Hampshire, being as it is presently mid-winter, frost is rampant. 50 feet is a long underground run, frost movement is very likely. If that pipe ever mechanically shifts, as in frost induced shifts, you might pinch the data cable into the power cable... AC line power conductors meet low voltage data conductors. Pow! Exploded NICs (at best).
Agree. I would certainly put the cable below the frost line. Believe it is about four feet here (25 minutes from Rochester, NH). A vertical entry point outside may be OK.
>I'd consider RF wireless data connections
Yes, that may be a viable option. Wireless is not as good as wired, however,
>or possibly fiber optics in that pipe
Too expensive, and I think about as vulnerable as twisted-pair for this application.
>I may be overly pessimistic…
I think so. Larry

4. RE: CAT-5 OUTSIDE
jb4home Feb-22-02 06:22 PM
In response to message 2
hi thanks for the thought that went into your reply.
I'm not building aircraft carriers in my garage/shop/office while i'm on line.

The whole idea is to get a network connection out to my private office where the kids can't wreck my files.
(if anyone is interested... i'm on a mac network. Couple of imacs + powermac + older quadra with a hugh monitor that i can't bare to part with).

The only real draw on the electric will be some lights and some current to run the computer (+ printer).
No big motors or draws on the line so is the coupling effect of your 50' run really still an issue?
If I pull the cat5 thru the solid pvc pipe and don't rub or knick it... won't the poly jacket keep the water (moisture out)?
Perma freeze? I'm on Long Island... Zero is usually the lowest... and the pipe should be stable.

I'm not looking for a 10 year solution, if the cable degrades in 4-5 years, i'll replace it. $10 worth of cable is meaningless to the budget. I'm more concerned about the 1. Lightning danger to the network 2. The noise on the line (which would possible make the connection worthless.

Under these main concerns...
Should I do it? Risk it?


6. RE: CAT-5 OUTSIDE
lbyard Feb-23-02 11:36 AM
In response to message 4
I believe I already answered your question as far as to what I would do. You have to decide what you will do. I assuming that whoever ran that electrical cable also ran an extra string to pull a new one… Larry

7. RE: CAT-5 OUTSIDE
allan8989 Feb-25-02 02:35 AM
In response to message 0
buddy, trust me, don't bother, use wireless device, both hub & nic. try www.computer4sure.com or www.compusa.com to buy some brand u need. even if u finish wiring the cable there the cost gonna be the same or even more than wireless.

mic


8. RE: CAT-5 OUTSIDE
lbyard Feb-25-02 12:20 PM
In response to message 7
I'll defer to your experience on this one. Larry

| Home | Guides | How to | Reviews | Online Store | FAQ | Forums | Forum Archives |
| Links | News | Newsletter | About Dux | Advertising | Contact Info | Privacy |