• Supported Platforms
• TX Matrix Plus Routers

• Related Topics
• Power Supply LEDs on the TX Matrix Plus Craft Interface
• TX Matrix Plus Seven-Input 420-A Power Supplies Overview
• TX Matrix Plus Seven-Input 420-A Power Supply LEDs
• Troubleshooting the TX Matrix Plus Power System
• TX Matrix Plus Preventing Electrostatic Discharge Damage.

Replacing a TX Matrix Plus Seven-Input 430-A Power Supply Input Power Tray

1. Removing an Input Power Tray
2. Disconnecting the DC Power Cables from an Input Power Tray
3. Connecting the DC Power Cables to the Replacement Input Power Tray
4. Installing an Input Power Tray
5. Connecting a Seven-Input 420-A Power Supply

Removing an Input Power Tray

To remove an input power tray:

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.
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.
3. Switch the circuit breakers on the power supply faceplate to the OFF position (O).
4. Loosen the captive screws that secure the input power tray to the power supply.
5. Grasp the metal handle of the input power tray and pull it down toward you. The circuit breakers are switched off as you pull the handle down.
6. Remove the input power tray from the power supply.

Disconnecting the DC Power Cables from an Input Power Tray

To disconnect the DC power cables from an input power tray:

1. Use a Philips screwdriver to loosen the screws on the metal input power tray cover. Remove the metal input power tray cover.
2. Remove the cable restraint. Use a Phillips screwdriver.
3. Remove the positive (+) DC source power cable lugs to the RTN (return) terminals on the upper row. Use a 7/16-in. (11 mm) nut driver to remove first the nuts, then the washers (see Figure 2).

   Figure 2: Disconnecting the Negative (–) DC Source Power Cable Lugs to an Input Power Tray

   

4. Remove the power lug separator over the terminal studs on the lower row of the input power tray.
5. Remove the nuts and washers from the power terminal studs on the lower row.
6. Remove the negative (–) DC source power cable lugs to the –48V (input) terminals on the lower row of the input power tray. Use a 7/16-in. (11 mm) nut driver to remove first the nuts, then the washers(see Connecting the Positive (+) DC source Power Cable Lugs to an Input Power Tray).

Connecting the DC Power Cables to the Replacement Input Power Tray

To connect the DC power cables from the input power tray:

1. Remove the nuts and washers from the power terminal studs on the lower row.
2. Attach the negative (–) DC source power cable lugs to the –48V (input) terminals on the lower row of the input power tray. Use a 7/16-in. (11 mm) nut driver to remove first the nuts, then the washers(see Connecting the Positive (+) DC source Power Cable Lugs to an Input Power Tray).
3. Reinstall the power lug separator over the terminal studs on the lower row of the input power tray.
4. Remove the nuts and washers from the power terminal studs on the upper row.
5. Remove the positive (+) DC source power cable lugs to the RTN (return) terminals on the upper row. Use a 7/16-in. (11 mm) nut driver to remove first the nuts, then the washers(see Connecting the Positive (+) DC source Power Cable Lugs to an Input Power Tray).
6. Attach the cable restraint. Use a Phillips screwdriver.
7. Reinstall the metal input power tray cover. Use a Philips screwdriver to tighten the screws on the metal input power tray cover.

Installing an Input Power Tray

To install a power supply input tray (Figure 3):

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.
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.
3. Switch the circuit breakers on the power supply faceplate to the OFF position (O).
4. Slide the input power tray into the power supply.
5. Grasp the metal handle of the input power tray and push it up toward the power supply.
6. Tighten the captive screws that secure the input power tray to the power supply.

Connecting a Seven-Input 420-A Power Supply

To connect a seven-input 420-A power supply to the power sources:

1. 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 TX Matrix Plus Preventing Electrostatic Discharge Damage.
2. Verify that a licensed electrician has attached cable lugs to the power cables that you supply.
3. Verify that the voltage across the DC power source cables leads is 0 V and that there is no chance that the cables might become active during installation. If needed, switch off the customer site circuit breakers.
4. Verify that the circuit breakers on the power supply faceplate are in the OFF position (O).
5. Loosen the captive screws on the cable restraint.
6. Remove the power lug separator that covers the lower row of terminal studs.
7. Remove the nut and washer from each power terminal stud.

   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.

8. Secure the negative (–) DC source power cable lugs to the –48V (input) terminals, first with a washer, then with a nut (see Figure 4).

   Use a 7/16-in. (11-mm) nut driver or wrench to tighten the nut. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.

   Caution: You must use an appropriate torque-controlled tool to tighten the nuts. Applying excessive torque damages the terminal studs and the power supply. The maximum torque that may be applied to this nut is 25 in-lb (2.8 Nm).

9. Replace the power lug separator over the lower row of terminal studs.
10. Remove the nuts and washers from the power terminal studs on the upper row.
11. Secure the the positive (+) DC source power cable lugs to the RETURN (return) terminals, first with a washer, then with a nut (see Figure 4).

    Use a 7/16-in. (11-mm) nut driver or wrench to tighten the nut. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.

    Caution: You must use an appropriate torque-controlled tool to tighten the nuts. Applying excessive torque damages the terminal studs and power supply. The maximum torque that may be applied to this nut is 25 in-lb (2.8 Nm).

12. Route the DC power cables through the cable restraints.
13. Tighten the cable restraint captive screws to hold the power cables in place. Attach the cable restraint to the input power tray.
14. Replace the input power tray cover.
15. Verify that the power cabling is correct, that the power cables are not touching or blocking access to other hardware components, and that they do not drape where people could trip on them.