Hi All,

During the controlled access yesterday afternoon (i.e. 02/06/2010 at ~16) Bill C. was kind enough to check on the 1B4 rack fans. It turns out the bottom most fan tray was not turned on.

After graphing the temperatures for the bottom most supply (West5, lvps3) and third from bottom (West3, lvps9) I see a large drop in temperature initially for most of the channels for West5 (there is a 1 degree C increase on U9 and up for some reason!) but within an hour it is back to the higher temperature. West3 didn't see a change. Also, all the LV channels were on and supplying power to the trays when Bill C. was there.

The only guess I have is the fan tray failed. In my opinion it seems unlike that a 4 degree temperature could be caused by just opening the rear door on the rack for a few minutes, but I certainly am no expert.

Here are a couple of highlight graphs:

Bottom must supply West5 (lvps3):

West5, U0 (i.e. left most channel when looking at the rear of the supply)

 

West5, U1

 

West5, U5

 

West5, U11 (i.e. right most channel when looking at the rear of the supply)

 

 

Middle supply, West3 (lvps9)

West3, U0 (i.e. left most channel when looking at the rear of the supply)

 

West3, U11 (i.e. right most channel when looking at the rear of the supply)

 

 

For historical purposes I went back to the when the bottom most supply was swapped on 1/13/2010 and the increase in temperature happened (the brief sharp dips are due to power cycling of the LV)

 

West5, U0 (i.e. left most channel when looking at the rear of the supply)

 

West5, U5

West5, U11 (i.e. right most channel when looking at the rear of the supply)

 

West3, U0 (i.e. left most channel when looking at the rear of the supply)

West3, U11 (i.e. right most channel when looking at the rear of the supply)