The accessory box shipped with the T640 router includes eighteen 4-AWG (21.2 mm2 ) cable lugs for the DC cables that attach to the terminal studs of each power supply (see Figure 1). the number of DC cables and cable lugs required varies depending on the power supply (see Table 1). Each DC power cable requires one cable lug. One cable lug shown is also used for the grounding the chassis.
![]() | Caution: Before router installation begins, a licensed electrician must attach a cable lug to the power cables that you supply. A cable with an incorrectly attached lug can damage the router. |
Figure 1: T640 DC Power Cable Lug

Table 1: Number of Cables Required
Power Supply | Number of DC Cables per Power Supply |
|---|---|
2-input 160-A DC power supply | 4 |
3-input 240-A DC power supply | 6 |
4-input 240-A DC power supply | 8 |
Table 2: T640 Power Cable Specifications
Quantity and Specification | Connector Specification |
|---|---|
Eight 4-AWG (21.2 mm2 ) (minimum) copper conductor, or as required by the local code. | Cable lug; dual hole, sized to fit 1/4-20 UNC terminal studs at 15.86-mm (0.625-in.) center line. |
![]() | Warning: For field-wiring connections, use copper conductors only. For other electrical safety information, see T640 General Electrical Safety Guidelines and Electrical Codes . |
![]() | Caution: You must ensure that power connections maintain the proper polarity. The power source cables might be labeled (+) and (–) to indicate their polarity. There is no standard color coding for DC power cables. The color coding used by the external DC power source at your site determines the color coding for the leads on the power cables that attach to the terminal studs on each power supply. |
![]() | Caution: Power cables must not block access to router components or drape where people could trip on them. |