Alarm installers commonly connect multiple sensors to a single zone. They do this by splicing the wires together. In this report, we will explain how alarm technicians splice the most common alarm wires, including:
- What a splice is
- Common alarm wire types - solid and stranded
- Splicing stranded wires
- Splicing solid wires
- Parallel splices
- Series splices
- When to choose parallel splices
- Two videos demonstrating splices
What Is A Splice?
To splice a wire is to touch the conductive portion of two wires together. This allows the electrons in a circuit to freely flow together. Alarm technicians commonly splice wires leading to different sensors together. This allows the sensors to share a single circuit. In theory, any number of sensors can be added to a single circuit. In practice, every sensor adds more resistance to the circuit.
Common Alarm Wire Types - Solid and Stranded
Alarm installations commonly use a mixture of wire types, depending on the type of sensor and the type of circuit. Powered devices such as motion detectors and acoustic glassbreak sensors often use solid wires, commonly 4/22, with the detection circuit being carried on one pair of wires and power on the other.
Magnetic contacts tend to be grouped together and need a wire that adds less resistance and is easier to splice, so alarm installers often use stranded 18/2 for these circuits. Sirens and strobes generate a large amount of resistance, and are commonly wired with stranded 18/2.
Different Wires Are Spliced Differently
In order to make a permanent connection, wires are twisted together and then covered. Splices add resistance to circuits, especially as time goes on, because exposing the copper to the elements causes it to oxidize. Incorrectly spliced wires are a common cause of false alarms and other alarm malfunctions. In these two videos, we will show you some methods of splicing wires so that they will not have to be redone after a decade of use.
Splicing Stranded Wires
Stranded alarm wires, which tend to be thicker, should be bent over and then crimped. Splices in dry locations can be covered with electric tape. Splices in humid locations should ideally be soldered. We demonstrate this in the video below: