Allied Telesis AT-DC2552XS - Manual (Page 49)

Stack Installation Guide for AT-2552XS L2 Data Center Switch
49
Caution
The PSU blank cover should be installed if an AT-PWR06 power sup-
ply module is not present in the chassis. This blank cover assures
that the correct airflow across the components in the chassis when a
power supply module is not installed. See “Installing Power Supply
Blank Cover” on page 51.
4. Slowly insert the AT-PWR06 power supply module into the PSU slot
until it is flush with the front of the chassis. See Figure 19.
Figure 19. Insert AT-PWR06 Module Into Chassis