Internet Router Hardware Guide

M160 Internet Router Hardware Guide
1. On the console or other management device c onnected to the master Routing
Engine, enter CLI operational mode and issue the following command to shut
down the router software. (If t wo Routing Engines are installed, also issue the
command on the backup Routing Engine.)
user@host> request system halt
NOTE: Wait until a message appears on the console confirming that the operating
system has halted.
For more information about the command, see the JUNOS Protocols, Class of
Service, and System Basics Command Reference.
2. For each power supply, press the power switch on the circuit breaker box to
the
OFF (O) position.
NOTE: If you are power cycling the power supply rather than shutting it off for a
time, wait at least 60 seconds after turning it off before turning it back on. If you
needtopoweritoffagain,waitforatleast60secondsafterpoweringiton.
3. Shut off the power flowing from both external power sources, 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.
4. A tt ach an electrostatic discharge (ESD) grounding strap to your bare wrist and
connect the strap to one of the ESD points on the chassis. Make sure t he router
is attached to a proper earth ground. For more information about ESD, see
“Preventing Electrostatic Discharge Damage” on page 226.
5. 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.
6. Using a 7/16-in. nut driver or wrench, loosen the outer nut securing the cable
lug to each terminal stud. Remove the outer nuts and washers, leaving the
innernutandwasheroneachstud.
CAUTION: Do not substitute a metric nut driver or wrench. A tool that does not fit
thenutsexactlycandamagethem.Ifa7/16-in.toolisnotavailable,usepliersor
an adjustable wrench.
7. Slidethecablelugoffofeachterminalstud.Leavetheinnerwasherandnut
on each stud.
194 R eplacing Power System Components