Coincidentally when Richard and I were in the Control Room, Nutsinee mentioned that there was a temperature alarm
in the PSL Enclosure.  Richard went outside to check whether or not the compressor was running - it was.
We went into the LVEA to check the AC/HEPA fan control unit.  It indicated that both AC units were off, all HEPA
FFUs were off and both AC units were off.

    We checked that the make up air fan was running at the science mode nominal of 20%.  It was.

    One thing that I noticed was different from previous encounters with the control unit was that the AUTO
button was illuminated.  Today and during yesterday's maintenance window were the only time that I can recall ever
seeing that button illuminated.

    Attached are two temperature trend plots.  One from today, the other for the past 10 days.  The change in
behaviour started around March 1st at ~20:00 (UTC) or around midday last Wednesday.

    The control unit is currently OFF.  We checked that the compressor was not running after exiting the
LVEA.  Indeed it was not running.