The configuration at my house has the main phone line coming off the pole, down to a junction box, where 2 phone lines leave and a single ground wire connects to the cold water plumbing.
I can't find any definite answers as to whether or not that ground wire is required, desired, or useless. The intent is on replacing the whole setup with CAT 5E (seeing how it's just as cheap as CAT 3 or phone cable) and re-routing the wires, but I don't know if I need to keep the ground wire. It looks like pretty standard 14 gauge wire, in a grey sheath.
The ground wire is from the surge protector in your Dmark. You need it. If you don't have this protection it will ground itself through your modem and PC. That is not a good thing in a smoking sort of way.
The whole thing started while I was sheetrocking and insulating the basement. The previous owner/and or phone company rather than drilling holes into the studs, took a chisel and cut a "V" notch on the surface of the stud so that the sheetrock would lay flat. So I'm looking at their handywork and wondering how I can re-route those wires - when I discovered that one of those grey wires wasn't a phone line - it was a ground wire. Now I'm wondering if I can route the ground wire to my panel instead and/or toss it.
Alright, Qwest here I come. I'm sure it will take about a week to sufficiently explain my question to them so that I get an intelligent answer.
It might be noted this what the Mythbusters had to disconnect to make the "lightning kills you through the phone" myth wr. With the ground connected, nothing happened. With it disconnected they had all sorts of fireworks. My experience is only with computers and surge protection. I know losing the bond between the phone and the power will blow modems, system boards and power supplies.
I always thought phone lines were grounded internally through the wire leading to the pole. Actually that's why I asked, I found too many people referring back to the grounding on the pole but never mentioning the grounding on site.
More accurately, the "protector unit" for the service is connected to an earth ground. 14-gauge used to be the norm. 12 was used for years. It's now
10-gauge.
That sounds right. If done to BSP (old Bell System Practice) specification, there should be a tag attached to the ground connection at the electrode (water pipe, ground rod, etc). It says something to the effect: On pain of death, thou shalt not remove the ground. It is enforced by the same thugs that enforce the mattress tag removal ban.
Until now...
It is.
Yes.
Only until a direct, or near-direct, lightning strike.
It doesn't make sense to connect Cat 5e wire to a "Cat 2-1/2" network. Cat 5e works fine for POTS (Plain Old Telephone Service) but is certainly overkill. It's NETWORKING wire (ethernet, yammer, yammer).
Uh, Cat 3 *IS* phone cable. :)
You need to KEEP IT.
If re-doing the system, I'd go 10-gauge, or at least 12.
I have encountered MANY services where the ground wire had NEVER been connected, some as old as 20-25 years. I declined to ask the customer if they had had to replace much/any of their equipment over the years.
I have found services bearing the above-mentioned tag with the ground clamp (and tag) "flapping in the breeze" (disconnected). Telephony gets no respect at all.
The "protector" at the phone entrance is NOT designed to clamp most surges - just the *HUGE* ones, like those delivered with a direct/near-direct lightning strike or a power line coming down across a phone cable or drop.
I once encountered an old (restored, fine) farmhouse that took a direct strike of lightning. The charge blew the protector housing off the outside of the home. Half of the housing was 50-feet away. I never found the other half. On the inside of the home, the bolt blew a 2-ft gaping hole in the lathe and plaster as it passed between a phone jack and electrical outlet across the living room.
The charge travelled along the underground "drop" (buried service wire) about
250-ft out to the road. There it blew apart a 25-pair splice module, interrupting service to about 20 subscribers beyond.
This protector WAS grounded, for all the good it did. With a direct strike of lightning, ALL bets are off.
Hi, Just remember grounding = safety issue. That's there for a reason. You notice surge protector on your Dmark. block? Where would surge current go? Say when lightning strikes.
All metallic cable SHEATH is grounded - or should be. The actual pairs are NOT, except back at the Central Office. An externally grounded cable pair is virtually unusable.
Telephone services have been grounded AT THE STATION (home, business, etc) since 1876.
Hopefully, my words have expedited your search.
I am a Network Technician (Installer/Repairman) and have worked for Qwest for
Old (older than every poster here) demanded the phone to be earthed to a water pipe. That is no longer acceptable. Phone must now be earthed to an electrode also used by cable TV and AC electric. Code also says that wire must be 12 AWG. Most use 10 AWG wire. Code also says that earthing wire must be short. That required to meet 'human safety' code. For transistor safety, that wire from demarc (NID) must be 'less than 10 feet', separated from all other non-earthing wires, no sharp bends, no splices, not inside any metallic conduit, and should be as short as practicable. These include post 1990 code requirements.
Same rules also apply to cable TV and AC mains earthing wire. All earthing wires should remain separated until all meet at their common earthing electrode. If it does not exist, you should install the earthing rod (for AC electric) before the telco comes out. You want them to use your 'better' earthing. Else they may install one that is insufficient (too short).
Only other ground for telephone wire is where that wire enters the telco's CO. However AC electric must be earthed at your earthing electrode AND at utility's transformer.
While inspecting, also confirm a safety ground wire from breaker box to water pipe is still connected. Best attached at a point where water pipe just enters the building and so that an earthing connection does not pass through any soldered connections. Your gas company may also demand same connection to gas pipe; a requirement that varies with natural gas companies.
Most important reas> Alright, I'd better call them then.
Why would this be? Sometimes it might be necessary to use metallic conduit to protect the earthing wire from physical damage.
Given that the main panel/disconnect will have a grounding bar where the Grounding Electrode Conductor terminates, is it good practice to run the cable TV and telephone earthing wires directly to this grounding bar?
Good information except the IEEE guide on surges and surge protection at:
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page 28-29) recommends the NID (and cable protector block) be mounted close to the electrical service, and their ground wire be connected to the grounding electrode conductor from the electrical service close to the panel. With high surge currents there will be significant voltage drop on the wire to the grounding electrode (the wire will have a much higher impedance at lightning frequencies than its DC resistance). With separate wires to the grounding electrode, that voltage will appear between the power wires and the telephone wires and may damage equipment connected to both. When the NID is connected with a short path to the power system neutral-ground bond, the phone and power wires will rise together.
Old practice often connected the NID ground wire to a nearby water pipe. When electronics is connected to both power and telephone wires that can produce failures. I moved mine to the grounding electrode conductor (but now I will be looking for thugs - thanks Jim). The NEC now allows connection to water pipes only within 5 feet of the entrance to the building.
. Telephone line protection here, here which AFIK follows Bell Canada (ATT) practice is a 'Protector' mounted where the telephone line enters the premises. Sometimes mounted outside but often inside the house. That protector requires a ground.
The telephone company would either have driven their own ground rod or, as in our case run a grounding wire to the incoming metal electrical conduit which is grounded by the power company; that ground is also bonded to metallic water pipe.
The protector (similar ones have been in use since the 1800s) provides voltage breakdown protection from each side of the telephone pair. Those are either repairable manually or by replacing small slide in units; they are essentially small spark gaps that will break down to ground if voltage exceeds a certain figure. Can't remember what that voltage is offhand.
Also these days if one is within distance of the server, Internet service can also be provided via the telephone pair.
The cable TV company have a coax entering the premises and it also has a grounded protector.
I really appreciate the response for this. I wasn't sure why that ground wire was there so I figure I'd better ask before moving it. I can leave it in its current position, bonded to the pipes, as the pipes are bonded to the panel ground, this would make the phone ground the shortest it can be - otherwise I'd have to route the phone ground wire to the other side of my house. But at least now I can drill the studs and put up nailplates for protection and peace of mind that I'm not gonna take out my phone service with an errant nail in the wall.
Just for comparison, the ROMEX was done in the same fashion, that was corrected as soon as I uncovered that little piece of handywork.
As to CAT 3 being phone cable, sorry I'm a computer systems architect the word CAT 3 means networking to me. Besides I thought CAT 1 was phone cable?
Before plastic pipe, that's the way grounding was done. Your installation is grandfathered. While using the interior metal water pipe as a grounding conductor is no longer permitted by NEC today, even for telephone or cable, as long as nobody comes along and replaces the interior metal pipe with plastic without jumpering it, you're OK. Check to make sure the water meter is jumpered and also the hot to cold at the water heater. In fact, there are still a lot of houses where the electric service grounding was done the same way as your phone grounding. The NEC restrictions against using interior water pipes for grounding applies to Residential only, because of the availability and common use of plastic pipe and popularity of DIY. Industrial and Commercial electric services are still permitted to this day to use interior metal water pipes as a grounding electrode conductor for an electric service.
When run in steel conduit, the wire through the steel acts as a choke and can significantly raise the impedance of the earthing wire. As volt notes, the NEC requires the conduit to be bonded to the earthing wire at each end so the conduit acts as a conductor in parallel to the earthing wire.
Connect them to the grounding electrode conductor close to where it leaves the service.
Well, I have both a bare Cu #6 Ufer ground coming out of the concrete foundation and a bare #6 GEC that goes to a ground rod and the metallic water service. They are both connected to the ground bar in the main disconnect. A few questions:
Is it OK to a use a bare #10 for the telephone/cable ground? You suggest that this wire should be clamped to one of the bare Cu #6 conductors, which one? Why is this better than running it to the ground bar in the main disconnect?
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