In case of electrical storm we wish to protect all equipment from surges
caused by lightning:- this will involve shutting down all equipment and physically
disconnecting plugs. In case of snow/ice storm, we wish to protect sensitive
equipment from water entering the dome. In this case the PLC and UPS will be
left running, in order to keep the dehumidifier and heater working.
The two MASS PCs share a monitor and keyboard, via a commuter device. If
you shut one of the PCs down, you cannot then commute to the other PC to shut
it down! For this reason it is best to shut down all 3 PCs from the WHT control
room.
Windows PC “mass-dimm” (DELL
box sitting on top of shelves): Connect from TODISPLAY2 using Applications
->Accessories -> VNC Viewer and entering the IP 161.72.36.35. This opens
a virtual copy of the desktop, from which you can shutdown using the usual
Windows menu procedure, from the Start button.
Linux
PC “mass-site” (NEXCOM aluminium chassis on shelf underneath): Connect from a Linux
machine using command “ssh
–l root 161.72.36.36” and then issue the command “/sbin/shutdown
–h now”. Requires pushing a small button on back of chassis
to power down completely.
Finally, shut down the robodimm (linux) pc by logging on as root and
issuing the command “shutdown –h now” or logging on to the console and
following the Red Hat menu procedure for shut down.
Once the PCs are powered down, it will be safe to disconnect any plug on
the Robo tower. Starting at the left hand plug, facing
east:
Now you should open the circuit breaker for the tower –
inside the smaller cabinet and marked with “D” and “X”. This disconnects the
PLC, protecting it from lightning.
The dehumidifier will automatically be switched on by the PLC if the
dome closes automatically due to high humidity. However if the temperature is
below 5 Celsius, the dehumidifier is disabled. In order to allow the
dehumidifier to run in cold wet conditions, the heater mains must be switched
on manually from the remote control pc in the Control Room. If a snow or ice storm forces the telescopes to be abandoned, but no
lightning activity is detected or expected, the equipment on the DIMM tower
should be all shut down except the dehumidifier, heater and PLC
which controls them. Follow the orderly shutdown of the PCs as detailed
above, and power down all electrical equipment – it is not necessary to
disconnect plugs. The blue plastic sheeting on the tower should be draped over
the two telescopes and as much of the computer equipment as possible and the robodimm pc cabinet shut if possible. If the dehumidifier or heater is not working, the MASS Windows PC should
be removed from the tower and stored indoors. Partial shutdown in Cold,
Wet conditions