Maintaining the Chassis

Your chassis is configured as specified in your order and is ready for installation and startup when it leaves the factory. As your communication requirements change, you can upgrade your system, add components, or change the initial configuration. Software and component upgrades require specific documents and other frequently updated information; therefore, only basic replacement guidelines are included in this publication.

There are two kinds of replaceable system components: those that support hot swapping and those that require the system power to be shut down before they are replaced. Redundant power supplies, line modules, and the fan assembly are hot swappable.

This chapter contains the following sections:

Warning Ultimate disposal of this product should be handled according to all national laws and regulations.

Removing and Installing Power Supplies

As your communication requirements change, you might want to upgrade your system and add or replace a power supply. This section contains the following power supply information:

Power Supply LEDs

The three LEDs (see Figure 4-1) on the power supply indicate the status of the power supply. The Input OK LED indicates that the power supply is on and receiving source power. The Fan OK signal indicates that the fan assembly is operating properly. The Output Fail LED is lit only when output voltage is outside of proper range,+3.3, +5, +12, and +42 VDC.

Figure 4-1: Power Supply

Overvoltage and Overtemperature Protection

The power supply monitors its own temperature and internal voltages. If the power supply detects an overvoltage or overtemperature condition, it shuts down to avoid damage to the power supply or other system components.

Note If the power supply shuts down, turn the power switch off (0), wait several minutes for the supply to cool, and then turn the power switch on ( | ). If the power supply shuts down again, remove and replace it.

Removing and Installing AC-Input Power Supplies

The redundant 1300W power supplies (AC-input) support hot swapping. When two power supplies are installed, you can remove or install one supply without affecting system operation. When power is removed from one supply, the redundant power feature causes the second supply to ramp up to full power and maintain uninterrupted system operation. In systems with dual power supplies, connect each power supply to separate input lines so that, in case of a line failure, the second source is available and can maintain uninterrupted power to the system.

A 20A modular power cord should connect each AC-input power supply to a separate site
power source.

Note Each AC-input power supply weighs 22 pounds.

Caution Use both hands to remove and install power supplies.

Tools Required

You need the following tools to remove and install a power supply:

A 1/4-inch flat-blade screwdriver to remove and install filler plates and to loosen or tighten the captive installation screw on the power supply.
Filler plates to install over empty power supply bays to protect the connectors
from contamination.

Removing AC-Input Power Supplies

To remove an AC-input power supply, follow these steps:

Step 1 Turn off the power switch on the power supply you are removing.
(See Figure 4-2.)

Caution Failure to turn off the AC-input power supply could result in equipment damage.

Figure 4-2: AC-Input Power Supply Switch, AC Connection, and Captive Screws

Step 2 Disconnect the AC power cord from the power source.

Step 3 Remove the input power cord from the power inlet.

Warning Before working on a system that has an on/off switch, turn off the power and unplug the power cord.

Step 4 Loosen the captive installation screw on the power supply with a screwdriver. (See Figure 4-2.)

Step 5 Grasp the power supply handle with one hand. Slowly pull the power supply out of the chassis toward you. (See Figure 4-3.)

Warning Voltage is present on the backplane when the system is operating. To reduce risk of an electric shock, keep hands and fingers out of the power supply bays and backplane areas.

Figure 4-3:
Power Supply Removal and Installation

Step 6 While holding the power supply handle with one hand, place your other hand underneath to support the bottom of the supply, as shown in Figure 4-4.

Step 7 Pull the power supply out of the bay and put it aside.

Step 8 If the power supply bay is to remain empty, install a filler plate over the opening and secure it with the mounting screws.

Warning Blank faceplates and cover panels serve three important functions: they prevent exposure to hazardous voltages and currents inside the chassis; they contain electromagnetic interference (EMI) that might disrupt other equipment; and they direct the flow of cooling air through the chassis. Do not operate the system unless all cards, faceplates, front covers, and rear covers are in place.

Figure 4-4: Handling an AC-Input Power Supply

Installing the AC-Input Power Supply

To install an AC-input power supply, follow these steps:

Step 1 Grasp the power supply handle with one hand. Place your other hand underneath to support the bottom of the supply, as shown in Figure 4-4.

Step 2 Place the power supply into the power supply bay and push the power supply into the bay until the power supply faceplate is flush with the cover.

Warning Voltage is present on the backplane when the system is operating. To reduce risk of an electric shock, keep hands and fingers out of the power supply bays and backplane areas.

Step 3 Tighten the captive installation screw by turning it clockwise.

Connecting the AC-Input Power Supply

Connect an AC-input power supply as follows:

Step 1 Plug a power cord into the power inlet of one AC-input power supply.
(See Figure 4-5.)

Step 2 Connect the other end of the AC-input power supply cord to an input line.

Warning The plug-socket combination must be accessible at all times because it serves as the main disconnecting device.

To complete the installation, see the section "Power Cord Connections."

Connecting Redundant AC-Input Power Supply

Connect the redundant AC-input power supply to a separate input line as follows:

Step 1 Plug in the power cord on the redundant AC power supply. (See Figure 4-5.)

Step 2 Connect the redundant power supply cord to an input line other than the initial power supply line.

Figure 4-5: Power Cord Connections

Powering Up the AC-Input Power Supply

Perform these steps to power up the AC-input power supply and confirm the installation:

Step 1 Turn the power switch of the AC-input power supply on ( | ).

Step 2 Verify that the LEDs (See Figure 4-1.) on the front panel of the power supply are in the following state within 5 seconds of operation:

Input OK: ON
Fan OK: ON
Output Fail: OFF

Removing and Installing DC-Input Power Supplies

The redundant DC power supplies support hot swapping. When two power supplies are installed, you can install, remove, or replace one supply without affecting system operation. When power is removed from one supply, the redundant power feature causes the second supply to ramp up to full power and maintain uninterrupted system operation. In systems with dual power supplies, connect each power supply to separate DC-input lines; in the event of a line failure, the second source is still available.

The DC-input power supply is required by many telcos because these installations are powered by -48 or -60 VDC batteries. From an operational perspective, the DC-input power supply has the same characteristics as the AC-input version.

Figure 4-6 shows the location of the DC-input power supplies in a redundant configuration. In a nonredundant configuration, the power supply goes in the slot labeled Power Supply 0.

Figure 4-6: DC-Input Power Supply Location

Removing the DC-Input Power Supply

To remove a DC-input power supply, follow these steps:

Step 1 Verify that the power is off to the DC circuit furnishing power to the power supply you are removing.

Warning Before connecting or disconnecting ground or power wires to the chassis, ensure that power is removed from the DC circuit. To ensure that all power is OFF, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the OFF position, and tape the switch handle of the circuit breaker in the OFF position.

Step 2 Turn off the power switch on the power supply you are removing. (See Figure 4-7.)

Step 3 Remove the terminal block cover by removing the two screws at the top and bottom of the terminal block. (See Figure 4-7.)

Step 4 Disconnect the input wires from the terminal block. (See Figure 4-7.)

Figure 4-7: DC-Input Power Supply

Warning When installing the unit, the ground connection must always be made first and disconnected last.

Step 5 Loosen and remove the captive screw on the power supply with a screwdriver.

Step 6 Grasp the power supply handle with one hand. Slowly pull the power supply out of the chassis toward you. (See Figure 4-3.)

Step 7 While holding the power supply handle with one hand, place your other hand underneath to support the bottom of the supply.(See Figure 4-8.)

Figure 4-8: Handling a DC-Input Power Supply

Step 8 If the power supply bay is to remain empty, install a power supply filler plate over the opening and secure it with the mounting screws. This protects the inner chassis from dust and prevents accidental contact with live voltage at the rear of the bay.

Warning Voltage is present on the backplane when the system is operating. To reduce risk of an electric shock, keep hands and fingers out of the power supply bays and backplane areas.

Installing the DC-Input Power Supply

To install a DC-input power supply, follow these steps:

Step 1 Verify that power is off to the DC-input circuit.

Step 2 Grasp the power supply handle with one hand and place your other hand underneath to support the bottom of the supply, as shown in Figure 4-8.

Step 3 Place the DC-input power supply into the power supply bay and push the DC-input power supply into the bay until the power supply faceplate is flush with the cover.

Warning Voltage is present on the backplane when the system is operating. To reduce risk of an electric shock, keep hands and fingers out of the power supply bays and backplane areas.

Step 4 Tighten the captive installation screw by turning it clockwise. (See Figure 4-7)

Connecting the DC-Input Power Supply

To connect the DC-input power supply to the input voltage source, follow these steps:

Step 1 Verify that power is off to the input circuit.

Warning Before performing any of the following procedures, ensure that power is removed from the DC circuit. To ensure that all power is OFF, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the OFF position, and tape the switch handle of the circuit breaker in the OFF position.

Step 2 Ensure that the power switch is off (0) on the power supply. (See Figure 4-9.)

Figure 4-9: Power Switch and Terminal Block Connections

Step 3 Remove the terminal block cover by removing the two screws at the top and bottom of the terminal block cover.

Step 4 Attach the appropriate lugs to the DC-input wires.

Step 5 From the top of the terminal block, wire the DC-input conductors to the terminal block as follows:

Ground wire to ground terminal
Return wire to "+" terminal
Battery wire to "-" terminal

Warning When installing the unit, the ground connection must always be made first and disconnected last.

Note

Step 6 After ensuring that all wire connections are secure, reinstall the terminal block cover.

To complete the installation, see the section "Powering Up the DC-Input Power Supply"
in this chapter.

Connecting the Redundant DC-Input Power Supply

To connect the redundant DC-input power supply to a separate input line, repeat the steps in the previous section, "Connecting the DC-Input Power Supply," but connect the redundant unit to a different DC-input line from the initial power supply.

Powering Up the DC-Input Power Supply

To power up the DC power supply and confirm the installation, follow these steps:

Step 1 Remove the tape from the circuit breaker switch handle.

Step 2 Turn the power supply power switch on (|).

Step 3 Verify that the Input OK and Fan OK LEDs on the power supply front panel is green. (See Figure 4-7.)

Replacing the Chassis Fan Assembly

This section describes how to replace the fan assembly, which is a single unit that draws in cooling air and distributes it across the route processor, switch modules and line modules.

Caution Before performing any procedures in this chapter, review the sections "Safety Recommendations," "Ensuring Safety with Electricity," and "Preventing Electrostatic Discharge Damage" in the chapter "Installing the Chassis."

Caution If you are replacing the fan assembly while the unit is operating, make sure the replacement fan assembly is ready to be installed immediately.

The chassis fan assembly draws cooling air in through the front right side of the chassis and exhausts the air through the back left side to cool the processor and line modules. The absence of cooling air can cause the interior of the chassis to heat up and can cause an overtemperature condition. Never operate the system if the fan assembly is not
functioning properly.

The fan assembly is located at the left of the chassis module cage. (See Figure 4-10.) The fan assembly is secured to the back panel with two captive installation screws.

Caution Never operate the system if the fan assembly is not functioning properly or if one is not reinstalled quickly. An overtemperature condition can result in severe equipment damage.

Figure 4-10: Chassis Fan Assembly

Tools Required

You need a 3/16-inch flat-blade screwdriver to remove the fan assembly.

Removing the Fan Assembly

To remove the existing chassis fan assembly, follow these steps:

Step 1 Locate the fan assembly (see Figure 4-10) at the left of the module cage, above the power supply.

Step 2 Use a flat-blade screwdriver to loosen each of the two captive installation screws by turning them counterclockwise.

Step 3 Loosen both screws on the chassis. These captive installation screws are fixed to the fan assembly; do not attempt to completely remove them.

Step 4 Grasp the fan assembly with both hands and pull it toward you and away from the backplane using steady pressure until it frees the backplane.

Step 5 Lift the fan assembly out of the chassis and place it in a safe place.

If the power has not been turned off, quickly proceed to the following section to reinstall a fan assembly.

Caution Never operate the system if the fan assembly is not functioning properly or if a fan assembly is not quickly reinstalled. An overtemperature condition can result in severe equipment damage.

Installing a New Fan Assembly

To install the new fan assembly, follow these steps:

Step 1 Hold the fan assembly with the fans facing to the right.

Step 2 Place the fan assembly into the front chassis cavity so it rests on the chassis, and then lift the fan assembly up slightly and align the top and bottom guides.

Step 3 Push the fan assembly into the chassis until the captive installation screws meet the chassis.

Step 4 Tighten each of the two captive installation screws.

Table of Contents

Maintaining the Chassis