NFPA 731 Section 4.8 requires grounding to be done in accordance with the National Electrical Code or NEC^® (NFPA 70).

The NEC^® covers grounding in Article 250. Typically, in a security system installation, an electrician provides a branch circuit for the security system installer and the security contractor takes it from there to supply the security system control panel. Sometimes the electrician is also licensed to install the security system. Either way, ensuring that the security system is properly grounded is a job shared by both types of installers.

Grounding and Bonding are two different things:

• Grounding means “connected (connecting) to ground or to a conductive body that extends the ground connection”. Basically, making a connection to the earth.
• Bonding means “connected to establish electrical continuity and conductivity”. Basically, joining things together so there is continuity between them.

The code language below provides general NEC^® rules for fixed in place equipment grounding that apply to many security system installations:

Below is a sample of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the latest NEC^® edition of NFPA 70.

250.4 General Requirements for Grounding and Bonding. The following general requirements identify what grounding and bonding of electrical systems are required to accomplish. The prescriptive methods contained in Article 250 shall be followed to comply with the performance requirements of this section.

(A) Grounded Systems.

(1) Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation.

(2) Grounding of Electrical Equipment. Normally non– current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.

(3) Bonding of Electrical Equipment. Normally non–current carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.

(4) Bonding of Electrically Conductive Materials and Other Equipment. Normally non–current-carrying electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.

(5) Effective Ground-Fault Current Path. Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path.