Maintaining the ATM Switch

Your switch 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. Detailed, up-to-date instructions are shipped with the replacement part upgrade kits.

Redundant power supplies, carrier modules, port adapters, the processor card, and the fan assembly are hot-swappable, replaceable system components.

This chapter contains the following sections:

Processor Card, Carrier Modules, and Port Adapters

The processor card, carrier modules and port adapters support hot swapping, which allows you to remove, install, and rearrange them without turning off the system power. When the system detects that a carrier module or port adapter has been installed or removed, it automatically runs diagnostic and discovery routines, acknowledges the presence or absence of the port adapter, and resumes system operation without any operator intervention.

Caution Turn off the system before removing the processor card. Removing the processor card from the system while it operates shuts down ATM switching. However, the processor card is hot swappable in all chassis; that is, no hardware damage occurs if it is removed while the power is on.

For detailed processor card, carrier module, and port adapter installation, replacement, and upgrade instructions, see the Processor Installation Guide and the ATM Port Adapter Installation Guide.

Power Supplies

This section includes the following power supply information:

LEDs

The green LED (see Figure A-1) indicates the status of the power supply and internal DC voltages. The LED stays on when the power supply is receiving source power, providing +5, +12, and +24 VDC to internal components, and it shows that all internal voltages are within tolerance.

If the source power or any of the internal DC voltages exceed allowable tolerances, the LED is not lit and the system environmental monitor messages indicate the out-of-tolerance line. Because the system requires all three output voltages for operation, the system malfunctions or shuts down if any of the internal DC voltages reach an out-of-tolerance state.

Figure A-1: Power Supply LED (AC Power Supply Shown)

Processor Card Power Supply LEDs

On the processor card front panel, the PS0 LED is lit when the power supply in the left bay, labeled PS0, is installed and is supplying power to the system. The PS1 LED is lit when the power supply in the right bay, labeled PS1, is installed and is supplying power to the system. Both the LEDs should be on in systems with redundant power. The processor card LEDs are shown in Figure A-2 and are described in Table A-1.

Figure A-2: Processor Card Power Supply LEDs

LED	Description
PS0	If the left bay power supply is operational, the PS0 LED is green. If the left bay power supply is turned off or is not operational, the PS0 LED is red. If the left bay power supply is not installed, the PS0 LED is not lit.
PS1	If the right bay power supply is operational, the PS1 LED is green. If the right bay power supply is turned off or not operational, the PS1 LED is red. If the right bay power supply is not installed, the PS1 LED is not lit.

Table A-1: Processor Card Power Supply LEDs

LED Description

PS0

If the left bay power supply is operational, the PS0 LED is green.
If the left bay power supply is turned off or is not operational, the PS0 LED is red.
If the left bay power supply is not installed, the PS0 LED is not lit.

PS1

If the right bay power supply is operational, the PS1 LED is green.
If the right bay power supply is turned off or not operational, the PS1 LED is red.
If the right bay power supply is not installed, the PS1 LED is not lit.

Overvoltage and Overtemperature Protection

The power supply monitors its own temperature and internal voltages. If the 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, wait several minutes for the supply to cool, then turn the power switch off (0), and then on (-). If the power supply shuts down again, remove and replace it.

Replacing AC Power Supplies

The 376W power supplies (AC-input) support redundant hot swapping. When two power supplies are installed, you can remove or install one of the supplies 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 maximum overcurrent protection for each power connection.

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

Caution Use both hands to remove and install power supplies.

Caution To avoid problems or damage to the switch, do not mix DC-input power supplies with AC-input power supplies in individual switches.

Note Each AC-input power supply weighs 11 pounds (4.98 kilograms).

Caution Keep hands and fingers out of the power supply bays. Voltage is present on the switch backplane when the system is operating.

Warning Do not touch the power supply when the power cord is connected. For systems with a power switch, line voltages are present within the power supply even when the power switch is off and the power cord is connected. For systems without a power switch, line voltages are present within the power supply when the power cord is connected.

Tools

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 screws on the AC power supply
Filler plates to install over empty power supply bays to protect the connectors from contamination

Removing the AC Power Supplies

To remove an AC power supply, follow these steps:

Step 1 Turn off the power switch on the power supply you are removing. (See Figure A-3.)

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

Figure A-3: AC Power Supply

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

Step 3 Remove the AC power cord from the power connector.

Step 4 Loosen and remove the captive installation screws on the sides of the supply with a screwdriver. (See Figure A-3.)

Caution Alternate loosening of the captive installation screws every one or two turns to avoid skewing the power supply.

Step 5 Grasp the AC power supply handle with one hand and slowly pull the power supply out of the chassis toward you. (See Figure A-4.)

Figure A-4: Power Supply Removal

Step 6 While holding the AC power supply handle with one hand, place your other hand underneath to support the bottom of the supply, as shown in Figure A-5.

Figure A-5: Handling an AC Power Supply

Step 7 If the power supply bay is to remain empty, install a blank 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.

Installing the AC Power Supply

To install an AC power supply, follow these steps:

Caution To avoid problems or damage to the switch, do not mix DC-input power supplies with AC-input power supplies in individual switches.

Step 1 Grasp the AC power supply handle with one hand and place your other hand underneath to support the bottom of the supply, as shown in Figure A-5.

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

Step 3 Tighten the two captive installation screws by turning them clockwise with a screwdriver.

Caution Alternate tightening of the captive installation screws every one or two turns to avoid skewing the power supply.

Caution Keep hands and fingers out of the power supply bays. Voltage is present on the switch backplane when the system is operating.

Connecting AC Power

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

Step 1 Plug a power cord into the power connector of the AC power supply. (See Figure A-6.)

Figure A-6: Power Cord Connectors

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

Note To connect the redundant AC power supply to a separate input line, repeat steps 1 and 2, but connect the redundant AC power supply cord to an AC-input line other than the initial AC power supply line.

Powering Up the AC Power Supply

To turn on the AC-input power supply and to confirm the installation, follow these steps:

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

Step 2 Verify that the green LED on the power supply front panel is lit (see
Figure A-1). A green LED indicates that the power supply is on and is receiving AC source power, providing +5, +12, and +24 VDC to internal components, and showing that all internal voltages are within tolerance.

Step 3 Verify that the appropriate processor card PS0 and PS1 LEDs are green. (See Figure A-2.)

Step 4 Use the show environment command to display the power supply and system status, as shown in this screen example:

Switch# show environment
Temperature:                        OK
Fan:                                OK
Voltage:                            OK
Power Supply#0 type: Astec,  status:    OK
Power Supply#1 type: Astec,  status:    OK
Switch#

If the LEDs or show environment command indicate a power problem or other system problem, refer to the section "Confirming the Installation" in the chapter "Installing the Chassis" and Figure 2-10 for troubleshooting information.

Replacing DC Power Supplies

Note Installation is approved for use with copper connectors only. Make the attachment of the chassis ground M4 pamnuts to the central office or other interior ground system with a number 6 AWG copper ground connector as a minimum. The chassis employs two threaded M4x7 chassis ground M4 pamnuts. These pamnuts must connect directly to the central office or other interior ground system, and they are located on the front of the chassis. The grounded chassis M4 pamnuts require M4 bolts and locking hardware, which are not included.

Figure A-7 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 A-7: DC Power Supply Location

Caution Use both hands to remove and install power supplies.

Caution Keep hands and fingers out of the power supply bays. Voltage is present on the switch backplane when the system is operating.

Caution Always install a filler plate over an empty power supply bay to protect the connectors from contamination.

Removing the DC Power Supply

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.

Caution To prevent problems with the switch, do not mix DC-input power supplies with AC-input power supplies in individual switches.

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

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

Step 2 Turn off the power switch on the power supply you are removing (see
Figure A-8).

Figure A-8: DC Power Supply Power Switch and LED

Step 3 Remove the terminal block cover by pressing the two plastic levers on each side of the terminal block (see Figure A-9).

Figure A-9: Terminal Block and Captive Screws

Step 4 Disconnect the DC-input wires from the terminal block. (See Figure A-9.)

Caution Disconnect the ground wire last.

Step 5 Loosen and remove the captive screws on the sides of the power supply with a screwdriver. (See Figure A-9.)

Caution Alternate loosening the captive installation screws every one or two turns to avoid skewing the power supply.

Step 6 Grasp the DC power supply handle with one hand and slowly pull the power supply out of the chassis toward you. (See Figure A-10.)

Figure A-10: Power Supply Removal

Step 7 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 A-11.

Figure A-11: Handling a DC Power Supply

Step 8 If the power supply bay is to remain empty, install a blank 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.

Installing the DC Power Supply

To install a DC power supply, follow these steps:

Caution To avoid problems or damage to the switch, do not mix DC-input power supplies with AC-input power supplies in individual switches.

Step 1 Grasp the DC power supply handle with one hand and place your other hand underneath to support the bottom of the supply, as shown in Figure A-11.

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

Step 3 Tighten the two captive installation screws by turning them clockwise with a screwdriver.

Caution Alternate tightening the captive installation screws every one or two turns to avoid skewing the power supply.

Caution Keep hands and fingers out of the power supply bays. Voltage is present on the switch backplane when the system is operating.

Connecting DC Power

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

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

Step 2 Ensure that the power switch is off (0) on the power supply. (See Figure A-12.)

Figure A-12: Power Switch and Terminal Block Connections

Step 3 Remove the terminal block cover by pressing the two plastic levers on each side of the terminal block.

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

Step 5 From the top of the terminal block, wire the DC-input power supply to the terminal block as follows (see Figure A-12):

Caution Connect the ground wire first.

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

Note Use 10-AWG copper conductor for the above connections.

Note Be sure to route the wires from the top of the terminal block, so that you do not obstruct access to the unit power switch.

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

Step 7 Connect the switch to the central office (CO) ground through the CO ground connector, as shown in Figure A-13.

Use the following guidelines when connecting the switch to CO ground:

If this is a new installation, remove the adhesive strip covering the CO ground connector on the switch.
Use a copper ground wire lug and attach it to the switch using two 1/4-inch M4 screws.
Use a 6-AWG ground wire.

Figure A-13: CO Ground Connector

Note To connect the redundant DC power supply to a separate input line, repeat steps 1-7, but connect the redundant unit to a different DC-input line than the initial power supply.

Powering Up the DC Power Supply

To turn on the DC power supply and to confirm the installation, follow these steps:

Step 1 Remove the tape from the circuit breaker switch handle, and restore power by moving the handle to the on position.

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

Step 3 Turn the power supply power switch on (-).

Step 4 Verify that the green LED on the power supply front panel is lit (see
Figure A-8). A green LED indicates that the power supply is on and is receiving DC source power.

Step 5 Verify that the appropriate processor card PS0 and PS1 LEDs are lit and are green (see Figure A-2).

Step 6 Use the show environment command to display the power supply and system status, as follows:

Switch# show environment
Temperature:                        OK
Fan:                                OK
Voltage:                            OK
Power Supply#0 type: Astec,  status:    OK
Power Supply#1 type: Astec,  status:    OK
Switch#

Replacing the Chassis Fan Assembly

The fan assembly is located at the left of the chassis card cage. (See Figure A-14.) The fan assembly is secured to the back panel with two captive installation screws.

Note Each replaceable component ships with installation instructions. Refer to these instructions for updated procedures and information.

Caution Before performing any procedures in this chapter, review the sections "Safety Recommendations," "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.

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

Figure A-14: Chassis Fan Assembly

Tools

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 (Figure A-14), which is installed to the left of the card cage, under 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 When both screws are loosened, unscrew them from 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 outward (toward you and away from the backplane) using steady pressure and jogging it until it is free from 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 two fans facing to the right.

Step 2 Place the fan assembly into the front chassis cavity so it rests on the floor of 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 screws meet the chassis.

Step 4 Tighten each of the two captive installation screws.

Table of Contents

Maintaining the ATM Switch