Cisco Cisco ONS 15310-MA SONET Multiservice Platform Installation Guide

© 2007 Cisco Systems, Inc. All rights reserved.

Product Name: 15310-MA-FTA

This document explains how to install the fan-tray assembly in the Cisco ONS 15310-MA. It also 
contains a description of the fan-tray assembly, installation equipment and procedures, and a list of 
specifications. As appropriate, use this document in conjunction with the Cisco ONS 15310-CL and 
Cisco ONS 15310-MA Procedure Guide, the Cisco ONS 15310-CL and Cisco ONS 15310-MA 
Reference Manual, and the Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide 
when working with the fan-tray assembly.

This document contains the following sections:

The fan-tray assembly is located at the top of the ONS 15310-MA shelf assembly, under the air filter, 
rear exhaust, and air inlet. The fan tray is a removable drawer that holds four fans, the fan-control 
circuitry, and the fuse-control circuitry for the ONS 15310-MA. After you install the fan tray, you should 
only need to access it if a fan failure occurs.

The new fan-tray assembly (FTA2) has a fuse-control circuitry that is capable of blowing a low-current 
fuse (1/4-A to 1/2-A). This is useful when you are using power distribution equipment that has a low 
current fuse connected in parallel with the main fuse to help detect any failures in the main fuse. The 
fuse-control circuitry independently draws a short current (approximately 900 mA) for about 0.7 seconds 
every 15 minutes (at 24 degrees Celsius or 75.2 degrees Fahrenheit), alternating between power supply 
inputs A and B. This allows the ONS 15310-MA to blow the low current fuse when there is a failure or 
loss of the main fuse and report an alarm (FAN alarm).