DC Power and Grounding Cable Specifications

On a DC-powered router, the power cable from each external DC power source attaches to terminal studs on the power supply, as shown in Figure 19. There are two sets of 1/4-20 UNC terminal studs for each power supply—the input set is labeled -48V and the return set is labeled RTN(+). The grounding cable attaches to the 1/4-20 UNC grounding studs located at the lower right corner of the power supply.

Figure 19: DC Power Supply Cable Connectors

Table 13 summarizes the specifications for the cables that you must supply for connecting to the power supply terminal studs and grounding studs.

Table 13: DC Power and Grounding Cable Specifications

Cable Type	Quantity and Specification	Maximum Equal Length
Power cables	Four 6-AWG (13.3 mm2) wire cables	None
Grounding cable	One 6-AWG (13.3 mm2) high-strand-count wire cable	None

For field-wiring connections, use copper conductors only. For other electrical safety information, see Electrical Safety Guidelines and Warnings.

Both the grounding studs and each pair of terminal studs on the circuit breaker box are spaced at 0.625-in. (15.86-mm) centers. The accessory box shipped with the router includes the cable lugs that attach to the end of the power and grounding cables (see Figure 20). The spacing of the holes in the lug matches the spacing of the terminal grounding studs.  

Before router installation begins, a licensed electrician must attach the cable lugs to the grounding and power cables that you supply. Cables with incorrectly attached lugs can damage the router (for example, by causing a short circuit).

Figure 20: DC Power Supply Terminal and Grounding Lug

During router installation, secure the grounding cable to the grounding studs and the power cables to the terminal studs, in that order. Secure the grounding cable lug with washers, then with 7/16-in. nuts. Then remove the plastic protective shield that covers the power supply terminal studs as shipped, and secure the power cable lugs to the terminal studs with locking washers, then with nuts, as shown in Figure 19. Replace the plastic protective shield. The nuts and washers that secure the power cables to the terminal studs are already installed on the studs.

For complete instructions, see Connect Power to a DC-Powered Router.     

Do not substitute a metric nut driver or wrench for the 7/16-in. nut driver or wrench needed to tighten and loosen the nuts on the terminal studs. A tool that does not fit the nuts exactly can damage them. If a 7/16-in. tool is not available, use pliers or an adjustable wrench.