Home . Search . About
ING . Astronomy . Public Information . Engineering
The power for the dome is supplied from the clip
centre power distribution board in the WHT control room and is routed
to the Dome Power Panel on the Nasmyth gantry before going to the
respective systems. The Dome Power Panel houses the local switches for
all power supplies to the Dome rotation, Top Shutters, Bottom Shutters,
Cranes and Control Transformer.
WHT DOME ROTATION AND SHUTTER
DOME ROTATION & BOTTOM SHUTTER CONTROLS
These are located behind the door of the
DOME CONTROL PANEL CP1
which is situated on the Nasmyth gantry.
The Dome can be
operated either from remote (computer control) or local position. The selector
switch is located inside the DOME CONTROL PANEL CP1
and is key operated.
Local Control - This is achieved by turning the key operated switch to
local control, push the 'Dome Motors Start' button then simply push the
button for clockwise or anticlockwise rotation. The Dome will turn for
as long as you hold your finger on the button. When finished be sure to
press the motor stop button.
shutter can be operated in either Main Drive
or Microdrive by
turning the key in the appropriate selector switch. With the shutters
closed the bottom shutter can only be operated in Micro Drive until
it is approximately 150mm away from the top shutter at which point
the main drive can be selected. Before opening the top shutter you
should always lower the bottom shutter first by 150mm, this ensures
that when you close the top shutter it will close fully against the
weather seal at the top of the dome. The bottom shutter can then be raised
to form a seal against the top shutter. The shutter controls are
such that they automatically switch off the power when the shutter has
reached its full travel in its selected mode. If you should be
operating in Main Drive you will find that the shutter will stop
approximately 150mm from the top shutter and you will have to complete
the closure in Microdrive.
controls for this shutter are located on the KONE
panel which is
located on the Nasmyth gantry a few metres to the left of the Dome
- Switch the Main Isolator on by turning the switch to
- Select 'Normal Control' on the control selector
- Release the Emergency stop interlock. This is done by
turning the key and allowing the big Red button to spring out.
- Push the green button marked 'Main Cont', this should
result in the green indication light being illuminated. If it doesn't check
that the Emergency stop is fully out and that the joystick is in the central
position before trying again.
- Wait a few seconds before operating the joystick to
move the shutter. Failure to wait will result in the system locking out.
- The shutter can then be operated on the joystick. It requires
little force to move the joystick and it should be operated gently - up
to raise the shutter and down to lower it.
This is for emergency purposes and should only
be selected if the main drive has failed. The key is held in the WHT duty
officer keypress. There is also a copy of the attached to the key for the
emergency stop interlock. Note that shutter motion with the aux drive is very slow, it takes close to 30 minutes to completely open or close the upper shutter with the AUX drive.
This switch should not be interfered with, the normal position is I +
ALL OTHER POSITIONS ARE FOR MAINTENANCE
ONLY AND ANY
ATTEMPT TO RUN THE SYSTEM IN THESE OTHER POSITIONS WOULD RESULT IN
SERIOUS DAMAGE TO THE DRIVE UNITS AND CABLES.
AUXILIARY DRIVE - EMERGENCY OPERATION
If in the event of a failure of the Main
system it is necessary to use the Auxiliary Drive units to close the
shutter then the following procedure will be required :-
Contact the Duty Officer for the keys to the Mode Selection switch
which are held in DO's WHT keypress.
Put the key in the Mode Selection switch and turn so that the arrow on
the barrel of the switch points to AUX DRIVE.
Provided the controls are available as described under Main Drive
operation the shutter can then be operated by pushing the buttons
marked AUX DRIVE DIR 1 or AUX DRIVE DIR 2 depending upon which
direction you want to travel. The button must be pressed all the time
you want the shutter to move.
-------- © 2007 Isaac Newton
Group of Telescopes --------
14 May 2007 Andrew Cardwell
Based on notes by R. Docherty from April 1992