Security alarm cable is a type of shielded cable used to connect up security systems. The sheath provides protection against frequency interference, which could otherwise cause false alarms to occur.  How do security alarm cables work? Security alarm cables consist of a number of strands of wire, all contained within a protective sheath. They connect the alarm device to a power supply, making the alarm sound when the device is triggered. If a sensor is inbuilt, movement is detected by the cable and a signal is sent to sound the alarm. Security alarm cables can sometimes be embedded into the ground or into walls to detect intruders. Types of security alarm cable Security alarm cables are all constructed in a similar way, but they can differ in terms of their size, in both length and diameter, and the materials they are made from. The sheath material can make a difference to their minimum and maximum operating temperatures. They can also have varying numbers of cores and strands within the cable.