Juniper T640 User manual

Replacing T640 Power System Components
The router has either one nonredundant power supply or two redundant, load-sharing
DC power supplies. Each redundant power supply is hot-insertable and hot-removable.
When a redundant power supply is powered down or removed, the other power
supply automatically assumes the entire electrical load for the router. If you have
only one power supply, you must power off the system before removing the power
supply. See Powering Off the T640 Router.
To replace a power system component, perform the following procedures:
■Replacing a T640 Two-Input 160-A Power Supply on page 1
■Replacing a T640 Three-Input 240-A Power Supply on page 7
■Replacing a T640 Four-Input 240-A DC Power Supply on page 17
■Replacing a T640 Power Supply Cable on page 23
■Replacing a T640 Power Supply Filter Element on page 30
Replacing a T640 Two-Input 160-A Power Supply
■Removing a T640 Two-Input 160-A Power Supply on page 1
■Installing a T640 Two-Input Power Supply on page 4
Removing a T640 Two-Input 160-A Power Supply
The power supplies are located at the rear of the chassis below the SIBs. Each
two-input 160-A power supply weighs approximately 23 lb (10.5 kg).
CAUTION: Do not leave a power supply slot empty for more than 30 minutes while
the router is operational. For proper airflow, the power supply must remain in the
chassis, or a blank panel must be used in an empty slot.
Replacing T640 Power System Components ■1

To remove a power supply:
1. Make sure that the voltage across the DC power source cable leads is 0 V and
that there is no chance that the cables might become active during the removal
process.
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.
2. For a nonredundant power supply, power off the system. See Powering Off the
T640 Router. For redundant power supplies, check that the other power supply
is functional.
3. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and
connect the strap to one of the ESD points on the chassis. For more information
about ESD, see Preventing Electrostatic Discharge Damage to an M Series, MX
Series, or T Series Routing Platform.
4. Switch the circuit breakers on the power supply faceplate to the off position (O).
NOTE: After powering off a power supply, you must wait at least 60 seconds before
turning it back on.
5. Remove the clear plastic cover protecting the terminal studs on the faceplate.
6. Using a 7/16-in. (11 mm) nut driver, remove the nuts and washers from the
terminal studs (see Figure 1).
2■Removing a T640 Two-Input 160-A Power Supply

Figure 1: Disconnecting Power Cables from a Two-Input 160-A DC Power Supply
7. Remove the cable lugs from the terminal studs.
8. Loosen the captive screws on the cable restraints on the right edge of the power
supply faceplate.
9. Carefully move the power cables out of the way.
10. Loosen the captive screws on the lower corners of the power supply faceplate
completely. Twist the ejector handles on the upper corners of the faceplate
counterclockwise to unseat the power supply.
11. Twist the ejector handles on the upper corners of the faceplate counterclockwise
to unseat the power supply.
12. Grasp the handle on the power supply faceplate, and pull firmly to start removing
the power supply. Slide it halfway out of the chassis (see Figure 2).
WARNING: Do not touch the power connectors on the rear of the power supply (see
Figure 3). They can contain dangerous voltages.
13. Place one hand underneath the power supply to support it, and slide it completely
out of the chassis.
CAUTION: Each two-input 160-A power supply weighs approximately 23 lb (10.5 kg).
Be prepared to support the full weight of the power supply as you remove it from
the router.
Removing a T640 Two-Input 160-A Power Supply ■3

Figure 2: Removing a Power Supply
Figure 3: Rear of the Power Supply Showing Midplane Connectors
Installing a T640 Two-Input Power Supply
To install a power supply (see Figure 4):
4■Installing a T640 Two-Input Power Supply

1. Make sure that the voltage across the DC power source cable leads is 0 V and
that there is no chance that the cables might become active during installation.
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.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and
connect the strap to one of the ESD points on the chassis. For more information
about ESD, see Preventing Electrostatic Discharge Damage to an M Series, MX
Series, or T Series Routing Platform.
3. Switch the circuit breakers on the power supply faceplate to the off position (O).
4. Using both hands, slide the power supply into the chassis until you feel resistance.
5. Twist the ejector handles at the upper corners of the power supply faceplate
clockwise until they stop.
6. Tighten the captive screws at the lower corners of the power supply faceplate
to secure the power supply in the chassis.
7. Remove the clear plastic cover protecting the terminal studs on the faceplate.
8. Remove the nut and washer from each power terminal stud. If no washers and
nuts are already installed, they should be in the accessory box.
9. Secure the cable lug on the DC power cable to the terminal stud, first with a
washer, then with a nut (see Figure 5). Use a 7/16-in. (11 mm) nut driver or
wrench to tighten the nut (see Figure 4). Apply between 23 lb-in. (2.6 Nm) and
25 lb-in. (2.8 Nm) of torque to each nut:
a. Secure each positive (+) DC source power cable lug to a RTN (return)
terminal.
b. Secure each negative (–) DC source power cable lug to a –48V (input) terminal.
NOTE: All inputs on the two-input 160-A DC power supply in slot PEM0 must be
powered by dedicated power feeds derived from feed A, and all inputs on the
two-input 160-A DC power supply in slot PEM1 must be powered by dedicated power
feeds derived from feed B. This configuration provides the commonly deployed A/B
feed redundancy for the system.
NOTE: INPUT 0 and INPUT 1 on the three-input 240-A DC power supply in slot PEM0
must be powered by dedicated power feeds derived from feed A, and INPUT 0 and
INPUT 1 on the three-input 240-A DC power supply in slot PEM1 must be powered
by dedicated power feeds derived from feed B. This configuration provides the
commonly deployed A/B feed redundancy for the system.
Installing a T640 Two-Input Power Supply ■5

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.
10. Loosen the captive screws on the cable restraints on the right edge of the power
supply faceplate.
11. Route the positive and negative DC power cables through the top and bottom
of each cable restraint.
12. Tighten the cable restraint captive screws to hold the power cables in place.
13. Verify that the power cabling is correct, that the cables are not touching or
blocking access to router components, and that they do not drape where people
could trip on them.
14. Replace the clear plastic cover over the terminal studs on the faceplate.
15. Switch the circuit breakers on the power supply to the on position (|).
NOTE: If you have only one power supply, or the system is completely powered off
when you power on the power supply, the Routing Engine boots as the power supply
completes its startup sequence.
16. Check the LEDs on the power supply faceplate. If the power supply is correctly
installed and is functioning properly, the DC OK LED lights steadily, and the CB
ON LED blinks momentarily, then lights steadily.
NOTE: After a power supply is powered on, it can take up to 60 seconds for status
indicators—such as the output status LEDs on the power supply, the show chassis
command display, and messages on the LCD on the craft interface—to indicate that
the power supply is functioning normally. Ignore error indicators that appear during
the first 60 seconds.
NOTE: After powering on a power supply, wait at least 60 seconds before turning it
off. If you have only one power supply, power off the system before turning off the
power supply. See Powering Off the T640 Router.
6■Installing a T640 Two-Input Power Supply

Figure 4: Installing a Replacement Power Supply
Figure 5: Connecting Power Cables to the Power Supply
Replacing a T640 Three-Input 240-A Power Supply
To replace a three-input 240-A power supply, perform the following procedures:
■Removing a T640 Three-Input 240-A Power Supply on page 8
■Setting the T640 Input Mode Switch on a Three-Input 240-A Power
Supply on page 11
■Installing a T640 Three-Input 240-A Power Supply on page 12
Replacing a T640 Three-Input 240-A Power Supply ■7

■Replacing the T640 Cable Restraint on a Three-Input 240-A Power
Supply on page 13
■Connecting DC Power to a Three-Input 240-A Power Supply in a T640
Router on page 15
■Powering On a T640 Three-Input 240-A Power Supply on page 17
Removing a T640 Three-Input 240-A Power Supply
To remove a three-input 240-A power supply:
1. Switch off the external circuit breakers to the power supply being removed. Make
sure that the voltage across the DC power source cable leads is 0 V and that there
is no chance that the cables might become active during the removal process.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and
connect the strap to one of the ESD points on the chassis. For more information
about ESD, see Preventing Electrostatic Discharge Damage to an M Series, MX
Series, or T Series Routing Platform.
3. Switch the circuit breakers on the power supply faceplate to the off position (O).
Figure 6: Three-Input 240-A Power Supply
NOTE: After powering off a power supply, wait at least 60 seconds before turning it
back on.
4. Remove the clear plastic cover protecting the terminal studs on the faceplate.
5. Using a 7/16-in. (11 mm) nut driver or wrench, remove the nuts and washers
from the terminal studs (see Figure 7).
8■Removing a T640 Three-Input 240-A Power Supply

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.
Figure 7: Disconnecting Power Cables from the DC Power Supply
6. Remove the cable lugs from the terminal studs.
7. Loosen the captive screw or screws on the cable restraint on the right edge of
the power supply faceplate.
8. Carefully move the power cables out of the way.
9. Loosen the captive screws on the lower corners of the power supply faceplate
completely.
10. Twist the ejector handles on the upper corners of the faceplate counterclockwise
to unseat the power supply.
11. Grasp the handle on the power supply faceplate and pull firmly. Slide it halfway
out of the chassis (see Figure 9).
12. Place one hand underneath the power supply to support it, and slide it completely
out of the chassis.
Removing a T640 Three-Input 240-A Power Supply ■9

WARNING: Do not touch the power connectors on the rear of the power supply (see
Figure 8). They can contain dangerous voltages.
Figure 8: Rear of the Power Supply Showing Midplane Connectors
CAUTION: Each three-input 240-A power supply weighs approximately 25 lb (11.3 kg).
Be prepared to support the full weight of the power supply as you remove it from
the routing platform.
CAUTION: Do not leave a power supply slot empty for more than a short time while
the router is operational. For proper airflow, the power supply must remain in the
chassis or a blank panel must be used in an empty slot.
10 ■Removing a T640 Three-Input 240-A Power Supply