Replacing the power supply

About replacing the power supply

Replacing the power supply consists of the following procedures:

Removing a power supply
Installing a power supply
Caution
The power supply in the C3100/C6100 NetCache appliance is different from the power supplies in the C700 series of NetCache appliances. These power supplies are not interchangeable.

Power supply compatibility

Be aware of the following caution regarding the compatibility between the two power supplies in the NetCache appliance.

Caution
When replacing a power supply, be sure not to mix two different power supplies. The two power supplies in your C3100/C6100 must have the same part number.

Removing a power supply

To remove a power supply, complete the following steps.

WARNING
To avoid an energy hazard, you must disconnect the power supply before removing it from the C3100/C6100.

Note
Because you have two power supplies that are hot swappable, there is no need to shut down the NetCache appliance.

Step	Action
1	Identify the failed power supply from console or LCD screen. Note The power supply identifiers, PS1 and PS2, are silk-screened onto the NetCache appliance chassis.
2	Turn off the power switch and disconnect the power to the failed power supply on your NetCache appliance.
3	If you have...	Then...
	AC power supplies	Lift up the clip lock and unplug the power cord from the appliance power supply.
	DC power supplies	Turn off the power at the DC power source for this power supply. Remove the cover from the power supply terminal block and set it aside. Using a #2 Phillips screwdriver, remove and save the screws securing the connections to the power supply in the following order: For positive ground installations: first negative (-), then positive (+), then ground ( ) For negative ground installations: first positive (+), then negative (-), then ground ( )
4	Loosen the power supply thumbscrews by turning each thumbscrew counterclockwise.
5	Pull the power supply out of the power supply bay. WARNING The power supply is heavy. Support the bottom of the unit while removing the unit from its bay.
6	Set the power supply aside.

Installing a power supply

To install a power supply, complete the following steps.

Step	Action
1	Verify that the switch on the power supply is turned off.
2	Push the power supply slowly and firmly into the bay until the power supply is firmly seated.
3	Secure the power supply by turning the thumbscrew clockwise until it stops.
4	If you have...	Then...
	AC power supplies	Plug the power cord into the power cord receptacle on the power supply and secure it with the clip lock.
	DC power supplies	Using a #2 Phillips screwdriver and the screws you saved, secure the ground ( ), positive (+), and negative (-) connectors to the power supply, as described in DC power supply connections. Cover the power supply terminal block with the cover that you set aside.
5	Turn on the power to the new power supply in your NetCache appliance.

DC power supply connections

You can use this power supply in both positive and negative ground installations. For example, the DC power system in telephone central offices (telco facilities) typically uses a positive ground and negative power source (-48V).

For positive ground systems

Connect the power supply terminals as described in the following table in the order listed.

Power supply terminal	to	DC bus terminal
Ground ( )		System ground ( )
Positive (+)		+ terminal of the 48V power source
Negative (-)		- terminal of the 48V power source

For negative ground systems

Connect the power supply terminals as described in the following table in the order listed.

Power supply terminal	to	DC bus terminal
Ground ( )		System ground ( )
Negative (-)		- terminal of the 48V power source
Positive (+)		+ terminal of the 48V power source

The following illustration shows the two DC power supplies. The labels for the positive (+), negative (-), and ground ( ) terminals are below the terminals.