Install Guide

Fans
The S4048T-ON comes from the factory with two PSUs and four fan modules installed in the chassis. The fan modules and the
power supplies, which have integrated fans, are hot-swappable.
NOTE: To run the system, the four fan slots must have operating fan units. If you do not install a module in each slot, the
system shuts down in one minute.
In addition to the power supply modules, you can order and install fan modules separately.
The system supports two airflow direction options. DO NOT mix airflow types in a chassis; you can use only a single airflow
direction in a chassis. If you mismatch the airflow directions, the system powers down in one minute.
● Normal—airflow is from the I/O panel to the PSU.
● Reversed—airflow is from the PSU to the I/O panel.
All fans and PSUs in a configuration must be in the same airflow 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 affect 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 to accurately determine replacement intervals.
Topics:
• Components
• Fan module installation
• Fan module replacement
• Fan air filter replacement
Components
The following list the fan components:
● S4048T-ON fan module
● S4048T-ON fan module—reverse flow
Figure 19. S4048T-ON PSU-side view
1.
PSU1 2. Fan modules
3. RS-232/RJ-45 serial console port 4. PSU2
5. 10/100/1000BaseT Ethernet management port
7
Fans 29