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Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter1 Shelf and FMEC Hardware
1.9.1 Fan Speed

1.9.1 Fan Speed

If one or more fans fail on the fan-tray assembly, replace the entire assembly. You cannot replace
individual fans. The red Fan Fail LED on the front of the fan tray illuminates when one or more fans fail.
For fan tray replacement instructions, refer to the Cisco ONS 15454 SDH Troubleshooting Guide. The
red Fan Fail LED clears after you install a working fan-tray assembly.
Fan speed is controlled by TCC2/TCC2P card temperature sensors. The sensors measure the input air
temperature at the fan-tray assembly. Fan speed options are low, medium, and high. If the TC C2 card
fails, the fans automatically shift to high speed. The temperature measured by the TCC2 sensors is
displayed on the LCD screen.

1.9.2 Air Filter

The ONS 15454SDH contains a reusable air filter that is installed beneath the fan-tray assembly.
The reusable filter is made of a gray, open-cell, polyurethane foam that is specially coated to provide fire
and fungi resistance. Spare filters should be kept in stock. Clean the filter every three to six months.
Replace the air filter every two to three years. Avoid cleaning the air filter with harsh cleaning agents or
solvents.
1.10 Power and Ground Description
Ground the equipment according to standards or local practices.
The ONS 15454 SDH has redundant –48 VDC power connectors on the MIC-A/P and MIC-C/T/P
faceplates.
To install redundant power feeds, use the two power cables shipped with the ONS 15454 SDH and one
ground cable.
For details, see the “3.17 MIC-A/P FMEC” section on page 3-30 and the “3.18 MIC-C/T/P FMEC”
section on page 3-33.
Caution Only use the power cables shipped with the ONS15454 SDH.
1.11 Alarm, Timing, LAN, and Craft Pin Connections
Caution Always use the supplied ESD wristband when working with a powered ONS 15454 SDH. Plug the
wristband cable into the ESD jack located on the lower-right outside edge of the shelf assembly.
The MIC-A/P and the MIC-C/T/P FMECs in the E FCA area at the top of the ONS 15454 S DH shelf are
used to connect alarm, timing, LAN, and craft connections to the ONS 15454 SDH.
For details, see the “3.17 MIC-A/P FMEC” section on page 3-30 and the “3.18 MIC-C/T/P FMEC”
section on page 3-33.