Juniper MX104 - Figure 28: Connecting the Ground Cable to the MX104 DC Power Supply

Figure 28: Connecting the Ground Cable to the MX104 DC Power Supply
3. Remove the plastic cover protecting the terminal on the faceplate.
4. Verify that the DC power cables are correctly labeled before making connections to
the power supply. In a typical power distribution scheme where the return is connected
to chassis ground at the battery plant, you can use a multimeter to verify the resistance
of the –48V and return DC cables to chassis ground:
For –48V and –60V:
a. The cable with very high resistance (indicating an open circuit) to chassis ground
is the DC input cable (–).
b. The cable with very low resistance (indicating a closed circuit) to chassis ground
is the return cable (+).
For +24V:
a. The cable with very low resistance (indicating a closed circuit) to chassis ground
is the DC input cable (–).
b. The cable with very high resistance (indicating an open circuit) to chassis ground
is the return cable (+).
5. Remove the screws and washers from the terminals.
6. Secure each power cable lug to the terminal with the washers and screw (see
Figure 29 on page 120). Apply 27.4 lb-in. (3.1 Nm) of torque to each screw. Do not
overtighten the screw. (Use a number 2 Phillips screwdriver.)
a. Secure the positive DC source power cable lug to the return (+) terminal.
b. Secure the negative DC source power cable lug to the input (–) terminal.
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MX104 3D Universal Edge Router Hardware Guide