Installing and Repairing Telephone Systems: The Telephone Network Interface Device
There once was a time when the telephone company was responsible for all the telephone wiring in homes, but those days have gone the way of the Model T Ford. Today the telephone companies responsibility ends at their Network Interface Device (NID), that innocuous gray box mounted on the exterior wall of your home. They will still install the wiring in your home and repair it for you, for a hefty $100 per hour. Why pay that when you can do it yourself?
- Whose problem is it?
- A lucrative part-time business.
- Essential specialty test equipment and hand tools.
- Checking for a dial tone at the NID box.
- Open the consumer side of the box.
- Next time
Whose problem is it?
This is a true story. A couple of years ago my daughter in-law called me early on a Friday morning on her cell to tell me that her house phone was not working. She was not getting a dial tone on any of the phones in her house. She had called the telephone company and they told her that they were willing to send a technician out to check the lines but if the technician had to come inside her home to fix the problem they would charge her $100 per hour with a minimum charge being $100. If the problem turned out to be the NID or on the street side of the NID they would be no charge. Being the intelligent young woman that she is, she told them that she would get back to them after she consulted someone (me) who understood those things. Five minutes after arriving at her home, I called the telephone company back for her and told the girl that the problem was on their side of the NID and therefore definitely their responsibility. She asked how I could be so sure, so I started talking about Butt Sets and Network analyzers which was enough to convince her to not have the technician try and scam my daughter in-law.
A lucrative part-time business.
Just as my daughter in-law called me when her telephone quit working, your friends, relatives, neighbors, and even strangers will start calling you once they discover that you know how to install and repair telephone systems. People will gladly pay you $25 to $35 an hour to do what the telephone company would charge them $100 an hour, and in some cases, even more to do.
Essential specialty test equipment and hand tools.
These are the tools and test instruments that I consider essential, the ones that makes the job easier, and the ones that make you look professional.
- Fluke 3000 tone generator and probe set
- Fluke/Harris TS19 Basic Butt set
- DMM (Digital Multimeter) w/frequency measurement
- Multifunction telephone line analyzer
- Fluke Need-L-Lock Crimping Pliers
- Acme Staple Gun w/staples
If you were to buy all of these items at one time, they will cost you, depending on where you buy them, between $350 and $500. I will explain what each of these tools do when we come to the article in this series in which you will be using them.
Checking for a dial tone at the NID box.
Every telephone installation or repair project begins at the NID Box. The telephone company and repair technicians also often refer to the NID Box as the Demarcation Point in a telephone system because it marks or denotes the point in the system where the telephone company's responsibilities ends and the consumer's responsibilities begin. The NID Box is usually located on the outside wall of a home, near where the utility meter is located.
Open the consumer side of the box.
- Open the consumer side of the box by unfastening the screw securing the cover in the closed position.
- The modern Network Interfaces Devices are modular in design, so once you have the box open, unplug the type RJ45 connectors from the telephone company's side of the box.
- Plug in the Fluke/Harris TS19 Basic Butt Set and listen for a dial tone. Make sure that you have the Butt Set's tone—pulse switch set for tone dialing.
- If you have a dial tone, make a call to verify the line quality. If you have a dial tone and can make a call, the problem is with the house telephone system.
- If you do not get a dial tone when plugged directly into the NID jacks, the problem is with the telephone company's wiring and it will be their responsibility to fix it without any charge to the consumer.
NOTE: If you are just working on your own telephone system and do not want invest in a Fluke/Harris TS19 Basic Butt set which will cost you about $135, you can plug household phone that you know is in good working order into the NID Box with the same results. A $10 telephone from the discount store will work fine for this test but the TS19 comes in handy if you have to trace out an open phone cable.
Next time I will explain how to use the Fluke 3000 tone generator and probe set to find a break in the telephone wiring even if the wiring is concealed inside a wall, floor, or ceiling.
DIY Guide to Troubleshooting a Dead Telephone Line