Setup Guide

Fans

The S4048–ON comes from the factory with one PSU and three fan modules installed in the chassis. The fan modules and the power

supplies, which have integrated fans, are hot-swappable.

NOTE: To run the switch, the three fan slots must have operating fan units. If you do not install a module in each slot, the switch

shuts down in one minute.

In addition to the power supply modules, you can order and install fan modules separately.

The S4048-ON supports two airow direction options. Do not mix airow types in a chassis; you can use only a single airow direction in a

chassis. If the airow directions are mismatched, the S4048-ON powers down in one minute.

• Normal—airow is from the I/O-side to the PSU-side

• Reversed—airow is from the PSU-side to the I/O-side

All fans and PSUs in a conguration must be in the same airow direction.

Environmental factors can decrease the amount of time required between fan replacements. Check the environmental factors regularly. An

increase in temperature and/or particulate matter in the air might aect performance; for example, new equipment installation.

CAUTION

: Check the fans at six-month intervals and replace them as necessary. Regularly monitor the speeds of the cooling

fans in order to accurately determine replacement intervals.

Topics:

• Components

• Fan module installation

• Fan module replacement

• After S4048–ON installation

Components

The following are the S4048–ON fan components:

• S4048–ON AC power supply with integrated fan module

• S4048–ON AC power supply with integrated fan module—reverse ow

Figure 20. S4048–ON fan modules

Fans 31