Shielded Twisted Pair Cabling - Safe for the outdoors?

[Phokus]

I'm helping a non-profit organization try to network two floors together. I don't want to drill their walls to drop down an ethernet cable though (if i can avoid it that is). Would it be safe to drop down a cable through a window from the 2nd floor to the 1st floor? I'm worried about lightning strikes frying the equipment. Would shielded twisted pair take care of this?

 

[Iron Woode]

That's a good question.

You could always put a casing around it, like they do with car wiring in the engine bay.

Or if something long term is needed then PVC might come in handy.

 

[bobcpg]

Nope, STP will not resist a lighting strike. I think you'd be fine with it out a window. I think i'd worry about birds pecking at it before a lighting strike.

-bob

 

[kursplat]

i think if lightning were to hit the side of the building where the cable is hangung frim the window , replacing the cable would be the least of the problems.
good luck

I'm helping a non-profit organization try to network two floors together

and good for you

 

[kursplat]

well i've just come across this thread and you may want to reconsider....
good luck

 

[rw120555]

Bad idea, see the thread about "The people on Tech TV are dangerous." If you can't get the cable safely strung between floors, there are other (albeit slower) ways to bridge the two networks, e.g. homepna, wireless, homeplug. Write back if you want more details. But, a safely-wired connection between floors would give you the fastest performance, if you can get it to work.

 

[Bleep]

I have read all kinds of posts about this subject all over the net and have yet found any tests made to show either side of the argument.
Why not just use a 10 base T network and run Coax outside and make sure the outside of the Coax is grounded. I would not hesitate for a minute to run a cat 5 cable outside of the building if it is not suspended in the air above the building like a antenna. I have a antenna 70 feet up that is 135 feet long and have never had a lightning strike. I also have a large beam antenna that has never had a strike. Both of them have been up over 20 years.

Bleep

 

[Fatt]

The concern of running cat5 outside between two buildings has mostly to do with concerns about the different electrical potentials between two different buildings.

That really isn't an issue running between two floors.


I would just run the cat5 outside through a hole drilled all the way through the wall.
If it's a brick building you can cheat a bit by drilling through the wooden framing underneath the window.

A 3/8" hole is plenty and a 5/16 will get the job done as well.
A coat hanger can help you to fish the wire through the wall.

Don't forget...
Seal the outside of the holes with silicone and on the lower of the two holes make a drip loop. Imagine a J shape in the cable befor it goes back in, so that the hole in the wall is above the lowest point in the calbe.

Make both holes underneath the windows but as far to one side as possible so that the cable runs down next to the window beneath.

This should also give you a place to attach those little plastic cable holders with the little finish nail in them.

Oh, and you can find a sufficiently long drill bit at your local electrical contracting supply house for about 10 - 15 bucks.

 

[SgtBuddy]

Running Cat5 outside. Two months ago, I would have said bad idea.

Right now I am sitting in the desert, 38 miles from Iraq on a total infrastructure of CAT5 run outside. I just did a BER test on the run to my tent. 106meters! From a cheesy 3Com SOHO hub. 20% bit loss. DOH! This cable has been run over 2 years ago and has been outside on the dirt for its life. I looked at the ends. GOOD GAWD! What moron did this.

white blue
blue
white green
green
white orange
orange
white brown
brown

I reterminated 568B and redid the test, 0% bit error rate, and 1 bit error second over a 72 hour test. (damn good results if ya ask me). Cranked the freq up to 100MHz and got passing results.

Lightning strikes are nil here.

This stuff can handle outside use. Lightning strike worryers need to worry about somthing else.

Flame away

Run the cable. Fry some nics in the chance that aliens come down and hit your cat5 with their laser beams.

Just do what everyone has said....J loop the entry points and sillycone that hole up! Make it look good and, by god, terminate the end correctly. (which means use a standard and don't have 3 inches of bare wire sticking outta the friggen connector. morons, I tell ya.

 

[nightowl]

If you search for some of the posts by ScottMac you will see that running Cat5 outside is not safe without proper entry protection equipment. Sure many people have run Cat5 outside and not had a problem with lightning or other electrical problems but do you really want to take the chance? You risk frying your equipment or even someone else if the cable gets some type of electrical surge and it is improperly protected.

 

[Fatt]

Like I said...

The issue with running cable outside has to do with running it between two different buildings.

No two buildings are going to have the same electriical potential and without proper grounding you're going to get electron flow from building to building.

Running between two floors on the same building does not involve this concern.

 

[kursplat]

running Cat5 outside is not safe without proper entry protection equipment

ever test the "entry protection " on the phone and electrical services coming into your house ? 99% do not pass current building code. if your house is over 10yrs old it might not have a driven ground. if it does your nieghbor may not. i've seen houses that lose their neutral and have no grounding, and the people in it never know, but 3 houses away t.v.'s are burnning up because their house is trying carry all the return current. what happens when lightning strikes a power pole ? hopefully everything on it is upto code and at the worse it might take out the transformer. but everything connected to that pole is trying it's best to carry all that current. improper grounding and reversed polarity on the outlets in your house are way more likely to burn up equipment than a lightning strike.

 

[Bleep]

Some interesting statements here. Some are not as true as proported to be.
I take it that all the neighbors are hooked into the same master water line provided by the city, this is as good a ground as you would ever want. The electrical service is also grounded if not at the house at the pole where the line is divided out of the distribution transformer.

. but everything connected to that pole is trying it's best to carry all that current. improper grounding and reversed polarity on the outlets

Alternating current has NO polarity.
Try this, take a volt meter and hook one end onto a metal water pipe in the house and put the other probe into one of the wall socket slots, do you get 110 volts? maybe and maybe not if not try the other slot in the socket. you only need one wire coming into the house and use a ground for the return.
Bleep

 

[kursplat]

take it that all the neighbors are hooked into the same master water line provided by the city, this is as good a ground as you would ever want

true. as long as nobody has replaced some of the pipe with plastic , or the ground is not to dry or sandy. sorry for saying "polarity". hot , neutral , ground then.

The electrical service is also grounded if not at the house at the pole where the line is divided out of the distribution transformer.

wires get broken ,connections go bad, squirels love to chew up aluminum conductor.an open neutral and a bad house ground,(which is not uncommon) can make a mess of electronic equipment.

you only need one wire coming into the house and use a ground for the return.

but most people have 3 wires. 2 hots and a neutral. 2 hots a no neutral is a big problem without a good ground at the house. a water pipe ground is marginal at best.
when a water crew goes to change a meter they place jumper cables on either side of the meter , connected to the water pipe to make sure that any curent flow on the pipe is not interupted. that still doesn't always protect them from getting knocked on their butt somtimes.