Instruction manual
AC Power and Grounding
2-12
Installation, SPM, Maintenance, and Troubleshooting Supplement
WARNING:
When installing the control unit, make sure you meet the following 
grounding requirements:
■ The control unit, the central office trunk protector, and the AC power 
service panel should be as close to each other as possible.
■ Because equipment can be located throughout a building, the National 
Electrical Code requires that the ground point for the central office 
trunk protector be bonded to the AC power ground as shown in 
Figure 2-3.
■ The AC outlet and the single-point ground bar must be properly 
grounded as shown in Figure 2-1 and Figure 2-3.
■ Each control unit ground-screw terminal must be connected to the 
single-point ground bar by a #12 AWG or a #14 AWG solid copper wire. 
Figure 2-1 and Figure 2-3 show this connection.
■ This wire run should be as short as possible, preferably within
5 feet (152 cm), and not to exceed 10 feet (305 cm). See “Approved 
Grounds” later in this chapter, for more information.
■ The AC outlet must be connected to the 145D protector with a #12 
AWG or a #14 AWG solid copper wire.










