Understanding Cable Splices & Protection Methods
Cable Splicing
Many times when installing cathodic protection systems, there may be a requirement that: Underground cathodic protection (or anode) cables shall be free of splices. This means that the specification writer or customer requires that the underground cable be installed in one continuous length and the use of "splices" (to join two individual pieces of cable) is not allowed. There is an opinion that splices are bad or a weak link in the length of cable. This may be true IF the splice is
not installed correctly.
Splices are commonly used in Cathodic Protection solutions. The main purpose of a cable splice is:
- Make a low resistance, stable connection between two (or more) pieces of copper (most often) cable.
- To eliminate the ability of moisture to enter the splice, which will eventually cause the splice to fail.
Cable Connection
There are many ways to make a common cable-to-cable connection. This includes a compression crimp, mechanical split bolt, compression "butt" connector (the ends of the cable are butted together), a thermite weld (Cadweld) connection and more. The goal of the splice is to join the two cables together in such a way that they are compressed against each other, making a low resistance electrical connection.
Connection Protection
After cables are properly joined (spliced), the connection must be protected from water intrusion. Water around a cable splice can cause corrosion and the connection will eventually fail. To keep water away from the spliced connection, there are several methods to protect the cable connection. This can include layers of "electrical" tape, splice kits, shrink tubing and possibly more.
With the proper equipment, a bit of technique and a little practice, an underground cable splice connection can be very reliable and a useful tool when cable splices become a necessity.