We specialize in helping people make the transition from analog to digital telephone services, simple. If your intent is to totally disconnect from your local phone company, you need to isolate your inside wiring from the line or lines, if there are more than one feeding your home, that come from the telephone company central office a telephone company line is sometimes referred to as a "PSTN line" - PSTN is an acronym for "Public Switched Telephone Network". You need to disconnect the line even if it appears to be dead, because at some point the phone company could place voltage across that line for one reason or another, and that could damage your equipment, and even possibly start a fire!

So here is how to isolate your inside wiring from the telephone company's line. On the outside of your home, you should find a telephone company Network Interface Unit. This is the demarcation point between your wiring and the telephone company's wiring. It may not look exactly like the one in the picture at the left, but you will know it because the telephone cable coming to your home from the street, as well as one or more lines from inside your home will go into it. When you open it usually by undoing a single common screw , you will be able to access the wires going into your home, but not the ones coming from the street.

This is by design. There should also be a ground wire coming out of the telephone company's side of the box. It is important to leave the ground wire connected, since it can help guard against lightning damage to your home in the event that lightning strikes a nearby phone cable.

Note: There may be a few older homes that still have an old-style telephone company lighting protector such as the one pictured at the right, which has the cover removed on the outside of the home or sometimes it was placed inside the home, at the point where the outside telephone wiring came into the home. It's rather rare to come across that situation, since almost all of those older protectors were replaced with the newer style Network Interface Units years ago.

An even less common situation is to find the protector, or possibly a Network Interface Unit mounted on a pole at some distance from the home. These instructions aren't really intended to address those types of situations, although if you have a basic understanding of good telephone wiring practices and you read through these instructions, you may be able to figure out what needs to be done.

Telephone Line Grounding - AT&T Midwest | DSLReports Forums

The section below entitled "What about those old lightning protectors? Once inside the Network Interface Box, you should see one or more sets of screw terminals two or four screw terminals per line and short stubs of wire with a standard telephone plug on the end, plugged into a matching jack as shown here if you don't see the wire stub and plug, you may have a "plugless" Network Interface Unit - in that case, see the section below entitled "New advice for a new kind of Network Interface Unit".

If there is only one line coming into your home, there will probably only be one plug and set of screw terminals. Now, assuming that you are the sole occupant of your home, it should be sufficient to simply unplug all the plugs.

Unfortunately, that leaves too much opportunity for Murphy's Law "anything that can go wrong, will" to come into play. In this case, what can go wrong is a telephone company employee going to the wrong home yours , finding the plug unplugged, and plugging it back in.

Phone line grounding question

Note: The above photo shows part of a brand new Network Interface Box with no wiring installed. Your box will have one or more pairs of wires attached to the screws adjacent to the plug s. If the screws next to a particular plug have no wires attached, then unplugging that plug will be ineffective, since no inside wiring is connected to that plug.

If you open a box and see only screw terminals with no wires attached, STOP - something isn't right it is not uncommon for there to be four screws next to a plug but only two of them are wired, however if none of them are wired, then that plug is not being used with any inside wiring. Unplugging a plug next to totally unconnected screw terminals will NOT break the connection to the phone company's wiring. Also, we again remind you that these instructions are not intended to cover situations where there are multiple lines involved, such as the network interface box shown at the right.

You might encounter this type of box on the side of a condominium, apartment building, or other multi-family situation, or in a home where there were once multiple lines installed a home that was once used for business purposes, or possibly a telemarketing operation. There is simply no way we can tell you which wire s would be the proper one s to disconnect in a situation like this, and if you disconnect the wrong wires, you might interrupt service to a neighbor in a multi-family situation.

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Open and remove the cover. Locate the grounding clamp at the inside bottom of the network interface. Feed one end of the copper wire up through an access hole in the bottom of the network interface box and over to the grounding clamp. Slide the end of the wire under the clamp, and tighten the screw down to press the clamp against the wire and secure it in place.

Network Interface Device (NID)

Locate an area about 1 to 2 feet away from the network interface box, and clear of the foundation of the house. Using the sledge hammer, driver the grounding rod into the ground until about 4 inches are left protruding out of the ground. Route grounding wire down to the rod, and cut any excess wire away. Slide the wire clamp over the wire and rod and tighten the screw down to squeeze the rod and wire together to form a tight connection.

Replace the network interface cover back over the box, and insert the screws into each hole and tighten them down.

Laurie Brown has worked as a high school English teacher for the last several years and loves writing. She enjoys helping her students develop a love and appreciation for writing, reading, and literature. Laurie has a degree in education with a major in English.