those running dell 5500 series switches, confirmed on the 5524, may notice that one fan is always down (red) in Orion NPM. You may even be getting an alert for the down fan. This is by Dell 5500 series switch design. The Dell 5500 series switches have essentially secondary booster fans that only turn on when the internal temperature of the switch increase past a pre-determined temperature. When this happens the fan will come on and it will report as up (green) in Orion. This is all fine and good, however, you may not choose to receive alerts on something that is working properly from the manufacturer.
By tweaking the hardware sensor alert in Orion this can remediated. On the hardware sensor alert set the trigger with an AND or OR statement to exclude the fan name. Such as:
AND hardware sensor type not equal to fan.
OR hardware sensor type not equal to fan for both the trigger condition of warning and critical.