Some of these workstations were provided with the option to have a sensor installed that could tell if the case cover was closed or not, but those are rare. I personally have never seen one on any of the xw or Z workstations I have worked with, but there are standard wires available to plug one of those in.
I had no idea that one of the features of that sensor might be that the fan speeds would go way up if the cover was not fully closed.
So, for future readers, don't expect to find one of those sensors if you look, but if you do find one then make sure the cover is fully closed...... and failure of that sensor might even cause a ramp up of fan speeds even if the cover is closed. It should be easy to unplug that sensor if it is in place.
