Using Cat5e Cable outdoors????

[sugar222]

Hi everyone!

I'm going to instal my IP cameras system, most of them will be outdoor.

From the beginning my project didn't include fiber.

PoE cameras, 8 different locations; in future will be a total of 16 PoE cameras; next 8 indoor

For network I already have:
1. Managed Poe Switch Zyxel 1910-24hp
2. 8 IP PoE cameras Hikvision DS-2CD2032-I
3. Surge POE protectors for each camera line one at the IP camera side and one at the Switch side
4. FTP Cat5e Otdoor ethernet cable

My big concern is about outdoor LAN network construction to limit lighting damages!

Few questions:
1. Outdoor ethernet lines underground or overhead(I can do it both ways); Witch is the best option for surge protectors to work right? I am confused which option will work best!
2. Outdoor grade, grounded FTP in plastic conduit/duct or in an grounded metal conduit/duct?
3. Generally if in an grounded metal conduit/duct an outdoor grade UTP will work?
4. Also for multiple LAN lines in the same conduit/duct plastic or grounded metal, FTP is better do not interference with each one?

Underground: Instead of grounded RGS (Rigid Galv Steel), grounded copper water pipes will do some protection operating as an inductor to lightning surges? Copper pipes are thin 0.7mm-1mm. If ok, Copper pipes will be good for direct bury or need a kind of bitumen/asphalt coat?

If I go overhead I can use grounded galvanized flexible spring tube (like spring shower flexible conduit), but again it's thin

Outdoor lines are max 30m(in which, underground or overhead max20m)

Any suggestion and experience will be great!

Hi. Since you posted in a 12 year old thread, I've separated your post and created a new thread in our Networking forum.

-Thanks
ViRGE

 

[azazel1024]

1) do not do overhead unless you have zero choice. Buried is best.
2) Don't use metal conduit unless everything is grounded correctly and you are POSITIVE it is. Ground differential is a pain in the patoot.
3) Do not use STP, UTP only for outdoor use. See again ground differential issues when running shielded cable underground (goes for conduit) can be a problem
4) run multiple in the same conduit. Catagory cable is designed for multiple runs. Obviously the more, the higher the interference, however, cat5e is designed for operating environments where you are running a trunk of 20+ cables all right next to each other and still carry gigabit speeds to 100 meters in length.

metal conduit should offer zero protection against lightning strikes for whatever is running in it.

The issue is that lightning will generally go to ground through the path of least resistance. Running a big metal pipe underground a few inches to a couple of feet gives lightning a better ground path than "empty" ground, because the pipe acts as a large contact with the ground, otherwise it is discharging to ground in one small place.

Lightning would rather hit buried metal conduit than it would a bare patch of ground. One step below would be buried wires, but something like Catagory cable doesn't act as a terribly great ground path for lightning because it is both thin wire, but also within a couple of insulating jackets (which I'll grant, lightning can pass right through, but it DOES increase the resistance to ground).

For lightning protection you either go with fiber, or you go with copper wire and realize that ethernet surge protectors are maybe going to buy you down stream protection after the switch gets fried to keep the next piece of networking gear from getting toasted on a near area lightning strike (IE ground strike within a few feet to a couple of hundred feet). A direct strike is likely to still fry a lot of your network.

Now possibly giving lightning more attractive targets, like lightning rods with proper grounding and also far from where any underground wiring is running might provide some protection.

 

[imagoon]

Uh... to clarify:

Metal conduit is fine for direct burial assuming it has been designed for that use. The whole lightning comment above is without merit. I mean houses have 6+ foot grounding rods in the ground. Most have water fed to the house via metal pipes, metal for natural gas feeds and have metal pipes that handle sewage. This is why you often find older homes grounded to the water pipes rather than a copper rod.

PVC is recommended because it lasts longer. It also needs to be buried deeper than metal. Metal is normally safe at 12 inches, PVC: 18 inches and direct bury 24 inches unless a concrete slab is in place.

The rest is right. You need premise protection for anything going in and out except fiber. It is also recommended that you use outdoor flooded cables rather than standard inside wire.

Verify with your local code however.

 

[Cerb]

I can't speak for pro installation needs, but from a practical standpoint, ground the devices attached, and at each end. Not, "oh, this indoor switch has a ground wire going to wall," but using its ground tab to add a dedicated one, and making sure the cables going to the cameras aren't ungrounded antennas. The cable may not be a great path to ground, but it can be good enough to fry most of a LAN, if you trust the building's grounding to do all the work.

 

[azazel1024]

In all cases the conduit/wire should be buried below the 50 year frost line.

Metal conduit isn't a hazard from lightning, which is why it is used. As for the home electrical, you need to ground to something. Its regardless of any lightning issues. If you have no ground path you have no method to ground anything connected to the home's electrical system and thus you can be the ground path instead.

Ground path = miss wired/broken wiring/etc results in tripped breaker immediately instead of live chasis and getting toasted if you touch it and you have a path to ground. Thus bonding the ground to a house's plumbing (generally required by code) and also why the ground bar in your main panel is bonded to neutral and has to have a maximum of (IIRC) 20ohms (25?) resistance.

Your plumbing CAN be "live" from a lightning strike. A lightning strike nearby/hitting your home can fry the home's electrical system because it'll travel over the home's wiring both to ground and through the neutral back to the power station (actually probably to a lightning arrester on a nearby pole).

Lightning will take any ground path it can. Doesn't really matter what it is. There could be 100,000ohms of resistance on a path and it'll bleed some of the current through that path. You are talking millions of volts, so a few hundred or thousand ohms isn't that much resistance. The more you can reduce the resistance of a main path, the lower the induced current will be in higher resistance paths.

Lightning arrestors work by having a semi-conducting material or a spark gap where high voltage can bridge the gap dropping the resistance significantly bleedling a lot of the current through that path and reducing the induced current through the standard path on something like coax or telephone lines.

I am not aware of any lightning arrestors for catagory cable. Just surge protectors.

 

[JackMDS]

http://en.wikipedia.org/wiki/Surge_arrester


http://www.l-com.com/surge-protector-cat5-5e-6-poe-camera-protectors

 

[azazel1024]

Ohhhh thanks for the link. I have seen ethernet surge protectors, which generally work through a fusable link and/or limited ground arresting, but I hadn't seen any full on lightning arrestors for ethernet.