Nortel Passport 15000, Установка и обслуживание оборудования, Страница: 473 / 874

Chapter 17 Hardware procedures 473
Passport 15000, 20000 Hardware Installation, Maintenance, and Upgrade 5.2S2
Installing a lower cooling unit
Install a lower (rear) cooling unit to enable temperature control of the
Passport switch hardware in the lower position of a NEBS 2000 frame.
Prerequisites
• You must be familiar with “Safety considerations and best practices”
(page 53).
• You need an NTHR51AA or NTHR51AB version of a lower (rear)
cooling unit. Since the fans of the unit are on the rear face of the switch
hardware, that is, on the same side that the fabric cards plug into, the
lower cooling unit is also the rear cooling unit.
• You need a driver for the 10-mm (3/8-in.) screws that fasten each cooling
unit to the frame or rack.
• A lower cooling unit is accessed from the rear of the NEBS 2000 frame
or equivalent.
Procedure steps
1 While referring to the figures “A lower cooling unit NTHR51AA”
(page 475) and “A lower cooling unit NTHR51AB” (page 476), hold the
ends of the cooling unit so that
• you face the fans
• the open side is at the bottom
• a hand holds the narrow rear end
• a hand holds the fan end
2 Facing the rear of the Passport 15000 or 20000 switch, insert the narrow
end of the cooling unit between the uprights of the NEBS 2000 frame and
along the top of the shelf assembly.
3 Slide the cooling unit inwards until the mounting ears at the fan end touch
the frame uprights.
4 Align the mounting-ear holes with the screw holes on the frame uprights.
The cooling unit should be in position as shown in the figure “Location of
a lower (rear) cooling unit” (page 477).
5 While holding the cooling unit in position, loosely fasten a thread-forming
10-mm (3/8-in.) hex-head screw through an upper mounting-ear hole.