> Replacing the Chassis' Power Filter Units
> Up to two -48 VDC Power Filter Unit (PFU) assemblies can be installed in the chassis. Using two PFUs, the recommended default, provides load-balancing and redundancy. The PFUs are located in the lower-rear of the chassis.
> This chapter provides instructions for replacing a PFU in the event of failure.
> Caution: Although a single PFU can provide power for a fully loaded chassis, it is strongly recommended that two PFUs always remain installed for load-balancing and redundancy.
> ESD Caution: During installation, maintenance, and/or removal, wear grounding wrist straps to avoid ESD damage to the components. Failure to do so could result in damage to electrical components and could potentially void your warranty.
> Determining that a PFU has Failed
> The chassis can use one of several mechanisms to indicate a PFU failure. The first indicator is when the POWER LED on the PFU is off. If the LED is off and a starPowerState SNMP trap is generated with a value of Failed (2), the PFU needs to be replaced.
> If you do not receive this trap, try the following suggestions to diagnose the cause:

> • | Verify that the power switch is in the ON position.

> • | Verify that the RTN and -VDC lugs are attached according to the instructions provided in this document.

> • | Verify that the ground lug is attached according to the instructions provided in this document.

> • | Verify that the power source is on and is supplying the correct voltage and sufficient current.

> • | Check the cables from the power source to the rack for continuity.

> • | If a fuse panel is installed between the Power Distribution Frame (PDF) and the chassis, verify that the fuses are intact.

> • | If a fuse panel is installed between the PDF and the chassis, check the cables from the fuse panel to the chassis for continuity.

> Removing the Failed PFU
> In the event of a PFU failure, follow these instructions to safely remove the PFU from the system.

> Step 1 | Power down the PFU.

> Step a | Optional. If the circuit breaker on your PFU is equipped with a locking clip, move the clip to the right to unlock the circuit breaker’s actuator.

> Step b | Flip the circuit breaker on the PFU to the OFF position.

> Step c | Optional. If the circuit breaker on your PFU is equipped with a locking clip, lock the circuit breaker in place. Move the breaker’s locking clip to the right until the clip’s inside tang is recessed in the breaker’s actuator opening.

> Step 2 | Shut down the power source to the failed PFU.

> Warning: To avoid the risk of electric shock, verify that the power source is completely shut down before proceeding to the next step. Vor dem naechsten Schritt Spannungsversorgung abschalten, um einen elektrischen Schlag zu vermeiden.

> Step 3 | Use a #2 Philips screwdriver to remove the plastic cover from the power terminals.

> Step 4 | Remove the cable from the -VDC terminals using the following instructions. The -VDC terminals are the two terminals located at the bottom of the PFU.

> Step a | Remove the nuts and washers that secure the cable to the PFU. The nuts on the 165A PFU require a 9/16-inch nut driver or socket wrench

> Step b | Slide the power cable off the terminals.

> Step 5 | Remove the cables from both RTN terminals using the following instructions. The RTN terminals are the two terminals located directly above the -VDC terminals.

> Step a | Remove the nuts and washers that secure the cable to the PFU. The nuts on the 165A PFU require a 9/16-inch nut driver or socket wrench.

> Step b | Slide the return cable off the terminals.

> Step 6 | Use a #2 Phillips screwdriver to loosen the four screws that secure the PFU to the chassis.

> Step 7 | Grasp the handle on the PFU and gently pull it toward you. The PFU should easily slide out of the chassis.

> Step 8 | Proceed to the Installing the Replacement PFU section that follows.

> Installing the Replacement PFU
> Follow the instructions below to install the replacement PFU in the chassis.

> Step 1 | Verify that the circuit breaker on the replacement PFU is in the OFF position.

> Step 2 | Slide the PFU assembly into the PFU bay until it is flush against the chassis.

> Step 3 | Use a #2 Phillips screwdriver to tighten each of the four screws on the PFU to secure it to the chassis.

> Step 4 | Use a #2 Phillips screwdriver to remove the plastic cover from the power terminals.

> Each of the four power terminals is shipped with one nut and two washers. The 165A PFU has one lock-washer and one flat washer.
> Warning: To avoid electric shock, ensure that the power source is off before attaching power cables to the PFU(s) installed in the chassis. Spannungsversorgung abschalten vor Anschluss der Kabel an die Netzteile, um einen elektrischen Schlag zu vermeiden.

> Step 5 | Ensure that the PFU in the bay labeled Power Filter Unit 1 is powered off.

> Step a | Flip the circuit breaker actuator to the OFF position.

> Step b | Optional. If the circuit breaker on your PFU is equipped with a locking clip, lock the circuit breaker in place. Move the breaker’s locking clip to the right until the clip’s inside tang is recessed in the breaker’s actuator opening.

> Step 6 | Use a #2 Philips head screw driver to remove the plastic cover from the power terminals.

> Step 7 | Remove the nut and the lock-washer on the 165A PFU from each of the four terminals. The nuts on the 165A PFU require a 9/16-inch nut driver or socket wrench.

> Step 8 | Fasten the lug attached to the power return cable to the PFU:

> Step a | Insert the lug over the two terminals labeled RTN. These are the two top terminals on the PFU.

> Step b | Secure the lug to the RTN terminals using two of the four washers and two of the four nuts that were removed in step 3. The nuts on the 165A PFU should be torqued to 50 in-lb. (5.65 n-m).

> Step 9 | Fasten the lug attached to the power feed cable to the PFU:

> Step a | Insert the lug over the two terminals labeled -VDC. These are the two bottom terminals on the PFU.

> Step b | Secure the lug to the -VDC terminals with the remaining two washers and nuts you removed in step 7. The nuts on the 165A PFU should be torqued to 50 in-lb. (5.65 n-m).

> Warning: To avoid the risk of fire, take proper precautions to ensure that the power feed and return lugs are not touching. Um einen Kurzschluss zu vermeiden, duerfen sich die beiden Stromkabel nicht beruehren.

> Step 10 | Reinstall the plastic terminal cover.

> Caution: To avoid the risk of electric shock and/or potential damage to the system, never operate the chassis without the plastic terminal cover. In addition, the power and return lugs must not protrude past the edge of the plastic terminal covers. Any portion of the lug that is exposed must be covered with shrink wrap.

> Step 11 | Apply power to the PFUs using the information and instructions in the Applying Power to the Chassis section of the Applying Power and Verifying the Installation chapter of this guide.

> What to do with the Failed PFU
> If the failed PFU is still under warranty, return it to the vendor for repair.
> If the failed PFU is out of warranty, contact the vendor to determine if it can be sent in for repair at an additional cost.
> For new customers: Refer to the support area of http://www.cisco.com for up-to-date product documentation pertaining to installation, configuration, and maintenance. A valid username and password are required to use this site. Please contact your local sales or service representative for additional information.
> For existing customers with support contracts through Starent Networks: Refer to the support area of http://www.starentnetworks.com for up-to-date product documentation pertaining to installation, configuration, and maintenance. A valid username and password are required to use this site. Please contact your local sales or service representative for additional information.

Cisco Systems Inc.
Tel: 408-526-4000
Fax: 408-527-0883