Cisco NCS 2006 Hardware Installation Manual page 422

NTP-L54 Installing Fan-Tray Assembly in NCS 2015 Shelf
Do not force a fan-tray assembly into place. Doing so can damage either the connectors on the fan tray
Caution
or the connectors on the back panel of the shelf, or both.
Error messages appear on the TNCS/TNCS-O card, the fan-tray LED, and in the Cisco Transport Controller
Note
(CTC) when the fan-tray assembly is removed from the shelf or when a fan is not working.
Cisco NCS 2000 Series Hardware Installation Guide
394
Installing the Cisco NCS 2015 Door and Other Modules