Connecting DC Power to the M40e Router

Connect DC power to the router by attaching power cables from external power sources to the terminal studs on the circuit breaker box. Power cables are not supplied with the router. For DC power cable specifications, see M40e DC Power, Connection, and Cable Specifications.

Note: The router must be connected to at least two separate external DC power sources.

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 the circuit breaker box.

To connect DC power to the router (see Figure 1):

1. Verify that there is no power flowing from either external power source, so that the voltage across the leads of the power cables is 0 V. Ensure that there is no chance that the cable leads might become active during the procedure.
2. For each power supply, verify that the power switch on the circuit breaker box is in the OFF (O) position.
3. Using a Phillips screwdriver, loosen and remove the screws securing the protective shield over the terminal studs on the circuit breaker box. Remove the cover.
4. Install one flat washer and one nut (in that order) on each power terminal stud:
   • If no washers and nuts are already installed, they should be in the accessory box.
   • If two pairs of nuts and washers are installed on the studs, use a 7/16-in. nut driver or wrench to loosen the outer nut on each stud. Remove the outer nuts and washers, leaving the inner nut and washer on each stud.

     Caution: The inner washer and nut prevent direct contact between the power cable lug and the circuit breaker box, which can cause a short circuit.

5. Slide the power cable lugs onto the terminal studs. Install another washer and nut (in that order) on each terminal stud to secure each power cable lug.
   1. Connect the positive (+) source cable lugs to the return terminals, which are labeled RTN(+).
   2. Connect the negative (–) source cable lugs to the input terminals, which are labeled –48V.

   Using a 7/16-in. nut driver or wrench, tighten the nuts. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.

6. Bend the power cables at a radius appropriate for the AWG being used and tie them together to ensure that the power cables do not obstruct any other components. To identify the minimum bend radius for each type of power cable types, see published industry standards, such as the National Electrical Code (NEC) and Insulated Cable Engineers Association (ICEA). Do not bend a power cable beyond the specified minimum bend radius.
7. Verify that the source power cabling and the grounding cabling are correct, that they are not touching or blocking access to router components, and that they do not drape where people could trip on them.
8. Replace the protective shield over the terminal studs and use a Phillips screwdriver to tighten the screws.
9. Turn on the current from the power source so that voltage flows to the router.

Figure 1: Connecting DC Power Cables