Old NID on left. Modern on right. Open for a illustrative purposes. Tampering with Telco equipment may result in fines and/or lose of service.
Antique NID Here are some older protectors that some people will still have in their homes. The one on the Left was used in the 40's-60's. The customer wire is on top (historically correct). This is where you would install your own wiring. The fatter gray (olive) wire on top is the ground wire. The fat black wire on the bottom is the drop (not customer serviceable). The brass rails are shunts, which bypassed the red fuses underneath. The black bakelite (sometimes brass) round piece is the cover for carbon protectors, which shunt any over voltage to ground.
The protector on the right dates back to 1914. Notice it has no shunts and still used the red fuses. The carbon protectors are under the brass cap. It has no wiring because it is old and I do not want to disturb it. It lays out the same as the other.
Many homes still use these protectors. Do not be afraid of them. They will not affect your DSL service and are perfectly capable of protecting your line. You may want to brush off the dryer lint and cobwebs though. If you are doing your own wiring, do not mess with the drop wire. Remember that there is voltage on the line and it will bite you. Use good wire (cat3, no stranded or flat wire). If you are unsure, CALL A PRO.
FAQ by kadar