The desc ties this to the clusterState property of a UCS PsuControl object. ClusterState reports the health/coordination state of this chassis's power-supply redundancy group as a whole, which is the field an admin checks to know whether the PSUs are working together correctly as a redundant set rather than checking each PSU individually. Example: a clusterState indicating degraded redundancy would prompt an admin to check individual PSU status before, say, scheduling maintenance that involves pulling a power feed.