Here's some information on the operational modes of the power supplies:
Power Pools
The Mobility Access Switch supports three models of power supply units (PSUs).
350W PSUs—You can use the 350W PSUs for non-PoE models such as S3500-24T, S3500-24F, or S3500-
48T. You can also install two 350W PSUs for system redundancy.
600W PSUs—You can use the 600W PSUs for full PoE models such as S3500-24P or S3500-48P. You can
also install two 600W PSUs to create a larger PoE pool.
1050W PSUs—You can use the 1050W PSUs for full PoE models such as S3500-24P or S3500-48P.