You can replace internal power supplies as needed while the switch is operating ("hot swapping").
All installed power supplies must have the same airflow direction (front-to-back or back-to-front) and must also match the airflow direction of the fan modules.
If the power supply module has a red tab, the airflow is front-to-back.
If the power supply module has a blue tab, the airflow is back-to-front.
Caution
Power supplies that support PoE cannot be installed in switches that do not support PoE. The switch operating system prevents PoE power contribution from a power supply that is not listed for use with that particular switch model.