Installing and Repairing Telephone Systems: How to Splice Telephone wire
There are several methods that can be employed when splicing AWG 22 or 24 solid-copper telephone wire but the button splice device is the quickest and easiest for the inexperienced installer/repairman to use. Whenever possible you should replace the full section of wiring instead of splicing it but there will be times when splicing is the only alternative and this is the best way to do it.
- The tools and supplies that you will need.
- Adjust the wire strippers
- Preparing to make the splice.
- Making the splice.
- Recheck the line for continuity.
- Related articles and video
In Installing and Repairing Telephone Systems: Part 2, I explained how to use the Fluke 3000 tone generator and probe set to locate a break or short in telephone system wiring. Once you have located the break or short in the wiring, you will need to repair the problem. The best way to repair such a problem is to remove the old section of wiring and replace it with a new length of wiring between the fixed junction blocks instead of splicing in a short section somewhere along its length. Splices, no matter how expertly performed are always weaker than the original wiring. But there will be times when replacing the full length of the wire will not be possible and you will need to splice in a short length of wire to bridge gap caused by the defective section you cut out.
The tools and supplies that you will need.
- 3M Scotchlok Type UR Connectors
- Telephone station wire
- Klein ScotchLok Connector Crimping pliers
- Diagonal Pliers/Side Cutter Pliers/Wire Cutters
- Adjustable Wire Strippers
- Small flat-Blade screwdriver
Adjust the wire strippers
Using a short piece of the station wire as a test piece, adjust the wire strippers depth of cut so they cut through the cables outer jacket without cutting into the insulation of the individual enclosed conductors. This may take a few tries and several pieces of station cable to get right but it is essential that you get the cutting depth set correctly before using the strippers on the actual station wiring. These adjustable wire strippers are relatively inexpensive so I have different ones for every type of cable that I normally work with, that way I do not have to keep readjusting their cutting depths.
Preparing to make the splice.
First, using the Diagonal Pliers cut out a small section of the station wire where the break or short circuit has occurred.
Second, using the wire strippers, remove two inches of the outer jacket from the end of each section of station wire.
Third, using the crimping tool as pliers, tug on each of the individual exposed conductors to make sure you have removed the section where the break was. If the break still exist, the brokn wire will slip out of the jacket. If that happens you will have to cut the wire back further until you reach the intact section.
Fourth, cut a new piece of station wire four inches longer than the gap left by the piece you removed from the original wire. The reason for this is that you want the splice to be tension free once you make it.
Fifth, remove two inches of the outer jacket from each end of the station wire that you will be slicing in.
Making the splice.
When splicing 4-conductor station wire, you will be splicing red to red, green to green, black to black, and yellow to yellow. Therefore for each new section of station wiring that you splice in you will need eight Scothlok Type UR connectors.
To make the splices, simply insert the two wires to be spliced together all the way inside the connector, one wire per hole, and squeeze the button all the way down with the crimping tool. Do not strip the insulation off the wire first. The insulation will be pierced by the crimping action and the electrical connection made.
Once you have crimped the connector closed, gently tug on the wires to make sure they are being held firmly by the button connector.
Recheck the line for continuity.
Once you have replaced the bad section of station wiring, use the tone generator and receiver probe to recheck the line to be sure no other problem areas still exists in the wiring. If everything checks good, reconnect the house wiring at the NID.