European Southern Observatory New Technology Telescope

General :
Observations :
Operations :

SUSI CCD Cryostat Exchange

SUSI2:

Electrical connections and disconnections should be done by a member of the ODT
(or other qualified person authorized by ODT):

To remove SUSI2 dewar:

• Print this page and from now on write a mark

    in front of every operation as soon as it is finished.
    At the end of operation, hand it over to NTT coordinator.
• Run CCD RON/GAIN and/or Linearity tests.
• If possible, check rotator balance, running nttadmRot
• Press rotator A emergency switch.
• Press telescope emergency switch.
• On Wemmi, shutdown DCS by opening the fcdControl panel and pressing Shutdown.
• Switch off Fiera power on the back of the Fiera Power Supply chassis (left one)
• Open Fiera Front Electronics chassis front panel (right one).
• Disconnect Gigalink fibre and put the fibre protective cups on the fibre ends.
• Disconnect all CCD cables from dewar and place the 3 protective covers

(stored on ODT lab.). Temperature connector does not use a cover.
• Disconnect the two video cables from Fiera Video Board plus Preamp power cable.
• The Preamp box can stay mounted if desired with its cables wrapped around.

(it will not interfere with CCD dismounting).
• Disconnect Fiera Power cable, 220V cable and cooling pipes from both chassis.
• Disconnect Pulpo power and temperature cables from Fiera Power chassis.
• The Pulpo box can also stay mounted with its cables wrapped around.
• The remaining cables on Fiera Electronics (bias and clock) should be wrapped

inside the chassis and the protective cover remounted.
• Mount the two red rings from their parking position

to the central hanging plate of each of the two chassis.
• Dismount the two chassis using the crane and removing

the 4 bolts that fix them (one pair in each side).
• Using the manual control on the SUSI shutter control box

(under the Fiera Power Supply chassis),
open the SUSI shutter (shutter 1) by keeping the open button pressed.
• Then switch off the power of the Shutter Control without releasing the open button

(this will make the shutter to stay open until reconnected,
thus protecting the delicate curtains inside the structure).
• Disconnect the shutter cable from the SUSI shutter unit (in front of the CCD).
• Disconnect the N2 flushing tube from the SUSI shutter unit (right side).
• Using the crane to hold the CCD dewar from its hanging ring,

dismount the 4 bolts of the SUSI shutter unit (2 each side)
and bring loose the CCD together with the shutter.
• Lift slowly the CCD and bring it to an adequate surface (table).

Be careful when passing the shutter unit through the SOFI support structure (it barely fits inside...).
Place a dust protection (paper) over the shutter hole.

• Using the crane, bring the dewar together with the shutter unit into position over the filter wheel.

Don't forget to remove any dust protection from the shutter hole.
Check that the rubber light shield fits correctly between shutter and filter wheel flanges.
• Install the 4 bolts that fix the shutter unit the adapter, and tight once

the unit is properly aligned with all the alignment points.
• Connect the shutter cable to the shutter unit and switch on the shutter control box.

Check that the shutter works with the manual controls.
• Mount the two Fiera chassis. Power Supply chassis on the left (over the  shutter control box)

and Fiera Electronics to right (over Pulpo box).
•   Install the 4 bolts and tight them. Remove the red rings and place them on the parking positions

(if not removed they will crash with the SOFI sliding  rail on SOFI base when rotating the adapter).
• Connect 220V, Fiera Power cable and cooling pipes into the respective chassis.

Check the water circulation by sensing the temperature of the rubber tubes. Check for leaks also.
• Open Fiera Electronics front panel and take out the CCD side of the Bias and Clock cables.
• Connect the preamp power and the two video cables to the Video Board inside  the Fiera Electronics.
• Connect the Gigalink fibres to the respective sockets on the Comm Board of the Fiera Electronics.
• Ground yourself with one hand to the metal structure and remove the 3 protective covers from

the CCD dewar. Connect all 4 cables: Bias, Clocks, Video and Temperature (from Pulpo).
Route the cables through the corresponding cable holders on the Power Supply chassis.
• Make sure they are not subject to LN2 spills.
• Connect the Pulpo power cable to Fiera Power Supply and the temperature monitoring cable if any.
• Connect the N2 flushing tube to the Shutter unit right side (small white tube).
• Switch on the Power Supply and check that Pulpo is reading the temperature and vacuum of the CCD.
• Check the LEDs on the COMM Board to make sure power is Ok. Switch the LEDs off and remount the chassis cover.
• On Wemmi, start the fcdControl panel and start up the DCS software.

If you  can go up to Online, everything should be OK.
• Check that all cables and fibre are properly fixed and bring the CCD protective covers to the ODT Lab.
• Release rotator A emergency switch.
• Release telescope emergency switch.
• Run CCD RON/GAIN and/or Linearity tests.
• If possible, check rotator balance, running nttadmRot

 

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