In most new security system installations, the job site electrician will install the branch circuit to power the security power supply. Generally, the electrician runs an acceptable wiring method from the circuit breaker to a location specified on the plans and leaves a coil of wire inside a box or installs a receptacle to be used by the security alarm installer.

The rules might be different in each state when it comes to who is permitted to install a branch circuit for the security system. Always check the local code authority and adopted rules to see if a licensed electrician must install the branch circuit or if the security alarm installer is permitted to install any wiring ahead of the security system power supply.

In North Carolina for example, those installing security alarm systems must at least have a specialty (SP) license for fire alarm and low voltage (FA-LV). The SP-FA-LV license allows the licensee to install fire alarm, burglar alarm and low voltage wiring systems but the branch circuit supplying the security system must be installed “by others” who hold an electrical license suitable for the installation of branch circuits operating at higher voltage levels.

According to the NC State Board of Examiners of Electrical Contractors (NCBEEC) located here https://www.ncbeec.org/section-0800/#0804, A SP-FA-LV license authorizes the licensee to install, maintain, or repair only low voltage wiring and directly related wiring. Wiring is directed related if it:

(1) originates at the load-side terminals of a disconnecting means or junction box that:

(a) has been installed, complete with line-side connections, by others for the specific purpose of supplying the low voltage wiring system involved; and

(b) is permanently and legibly marked to identify the low voltage wiring system supplied; and

(2) is not installed in a location considered as hazardous under the National Electrical Code.