The first action (if you take any action) should be to disable the
audio alarm by holding the PMON reset button up for approximately one
seconds (it always seems to take more time) until the associated LED
lights up. By doing this, you are taking responsibility for
ensuring that the problem is followed up - Do NOT just go back to your
observations.
Subsequently to the reset, it may be appropriate to isolate the alarm
for a given antenna. To do this, switch the appropriate isolate switch
to the up position, and turn the key clockwise. You should then continue
to follow up the cause of the alarm.
Another alarms in the PMON rack that observers may need to respond to
is the UPS alarm. This alarm sounds
if the Control Building UPS is either charging or recharging. This will
happen if there is a `glitch' in the power supply. `Glitches' occur when
you change from mains power to generator power (and the reverse) as well
as when there is a drop out in the mains supply. When this alarm sounds,
cancel the audio alarm, then check that the alarm has reset after 5 minutes.
If it fails to reset in this period, the UPS may well be discharging:
There is around 20 minutes capacity on the UPS, so get help immediately.