Juniper MX240 Hardware Manual page 247

6. Remove the nuts and washers from the terminal studs. (Use a 7/16-in. [11 mm] nut driver or socket
wrench.)
7. Secure each power cable lug to the terminal studs, first with the flat washer, then with the nut (see
Figure 72 on page 251). Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.
Do not overtighten the nut. (Use a 7/16-in. [11 mm] torque-controlled driver or socket wrench.)
a. Secure each positive (+) DC source power cable lug to the RTN(return) terminal.
b. Secure each negative (–) DC source power cable lug to the 48V (input) terminal.
CAUTION:
the terminal block as you are tightening the nuts. Ensure that each nut is properly
threaded onto the terminal stud. The nut should be able to spin freely with your
fingers when it is first placed onto the terminal stud. Applying installation torque
to the nut when improperly threaded may result in damage to the terminal stud.
CAUTION:
supply is 36 lb-in. (4.0 Nm). The terminal studs may be damaged if excessive
torque is applied. Use only a torque-controlled driver or socket wrench to tighten
nuts on the DC power supply terminal studs.
NOTE: The DC power supply in slot PEM0must be powered by a dedicated power feed
derived from feed A, and the DC power supply in slot PEM2 must be powered by a
dedicated power feed derived from feed B. This configuration provides the commonly
deployed A/B feed redundancy for the system.
8. Replace the clear plastic cover over the terminal studs on the faceplate.
9. Verify that the power cables are connected correctly, that they are not touching or blocking access to
router components, and that they do not drape where people could trip on them.
10. If you are installing two power supplies, repeat Steps
Ensure that each power cable lug seats flush against the surface of
The maximum torque rating of the terminal studs on the DC power
3 through 9 for the other power supply.
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