Doc #: 2100-AD-015-0083 Revision: -
4m Cass Cage Electronics and Cable Removal
Author(s): John Donaldson, Miranda Saucedo, Tammie Lavoie
4m Cass Cage Electronics And Cable Removal
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Contents Revision History .................................................................................................................. 3
1.0 Purpose ..................................................................................................................... 4
2.0 Applicable To ............................................................................................................ 4
3.0 Scope ........................................................................................................................ 4
4.0 Definitions ................................................................................................................ 4
5.0 Training ..................................................................................................................... 4
6.0 Safety ........................................................................................................................ 5
7.0 Personnel, Equipment and Materials Required ....................................................... 5
8.0 Procedure ................................................................................................................. 5
9.0 Procedure Review................................................................................................... 14
10.0 Records ................................................................................................................... 14
11.0 References .............................................................................................................. 14
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Revision History
REV
Date Approved
Sections
Affected
Reason for Change
Remarks and/or Change Details
Name
-- 01/23/18 Initial Release J. Donaldson
T. Lavoie
Approved by:
John Donaldson
Name, ME Title
John Donaldson
Name, EL Maint
SigSci
Name, SciOps
Tammie Lavoie 23 January 2018
Tammie Lavoie, Safety Manager Date
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1.0 Purpose The intent of this procedure is to safely remove the Cass cage electrics and cables from the
Mayall 4 Meter Telescope.
2.0 Applicable To This procedure is applicable to the Electronics Maintenance (EM) and Facilities departments,
as well as any additional personnel who assist in completing these tasks. This includes
members working on the Mayall 4 Meter Telescope DESI Project.
3.0 Scope This document is a step by step procedure that outlines how to remove the electronics and
cables from the Cassegrain cage in the Mayall 4 Meter Telescope.
4.0 Definitions The acronyms and definitions referenced in this procedure are listed below.
4.1 4MAPS- 4 Meter Active Primary Support
4.2 AC- Alternating Current
4.3 ADC- Atmospheric Dispersion Corrector
4.4 DESI- Dark Energy Spectroscopic Instrument
4.5 ICCD- Intensified Charged Coupled Device
4.6 I/O- Input/Output
4.7 PMTC- Primary Mirror Temperature Control
4.8 RTD- Resistance Temperature Detectors
5.0 Training The training required for this procedure is as follows:
5.1 Fall Protection
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6.0 Safety The safety documents required for this procedure are listed below.
6.1 Daily Briefing Form
6.2 JHA Form
6.3 Fall Protection SOP
6.4 Rescue Plan SOP
7.0 Personnel, Equipment and Materials Required
Process #/Personnel Notes
4M Cassegrain Cage Electronics and Cable Removal
3 (3)-Electronical Maintenance
Equipment/Part/Tool List Location Notes
Cable Ties EM Shop N/A
D-Ring Straps 4 Meter/3rd Floor (2) 3’ Straps
Diagonal Wire Cutters EM Shop (1) Flush Cut Diagonal
Fall Protection EM Shop or
4 Meter/3rd Floor N/A
Nut Driver EM Shop (1) ᵌ⁄₁₆”
Retractable Webbing Lanyard 4 Meter/3rd Floor (2) 20’ Lanyard (Miller Scorpion)
Screw Drivers EM Shop (1) Standard Set
8.0 Procedure 8.1 Hook in to the retractors on the underside of the cell (JHA-1).
8.2 Go up on the lift (JHA-2).
8.3 Begin facing the cage door.
8.4 Working to the left, begin removing the electronic racks that are left of the Cass cage
door (Figure 1) (JHA-3). Note: All of the racks have stops on them, so they are able to
be pulled out to access the cables on the back without falling out.
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Figure 1: Cass Cage to the Left of the Door
8.5 The first rack contains the guider control and the instrument control (JHA-4).
8.5.1 Push down on the safety lock that is on top of the left rail.
8.5.2 Slide the rack out until it stops.
8.5.3 Remove the power cables that are plugged into the power strip behind the
prime focus power supply rack.
8.5.4 Remove all of the cables from the rear of the guider control box and the
instrument control box. Note: Attach a “to be removed” label to these cables.
8.5.5 Disconnect the two ground cables.
8.5.6 Remove the safety lock that is on top of the left rail.
8.5.7 Use two workers to slide the rack out and place it on the cart.
8.6 The second rack contains the prime focus power supply, the guide
probe/mirror/rotator power, and an Ethernet hub (JHA-5).
8.6.1 Push down on the safety lock that is on top of the left rail.
8.6.2 Slide the rack out until it stops.
8.6.3 Remove the power cables from the prime focus power supply and the guide
probe/mirror/rotator power that are plugged into the power strip behind the
prime focus power supply rack.
8.6.4 Remove the prime focus power supply cables from the rear of the box. Note:
Attach a “to be removed” label to these cables.
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8.6.5 Remove the Ethernet cables that are: Computer Room, F/8 baytech, mystery
cable, wavefront, and prime from the Ethernet hub. Note: Attach a “to be
removed” label to these cables.
8.6.6 Remove the safety lock that is on top of the left rail.
8.6.7 Use two workers to slide the rack out and place it on the cart.
8.7 The third rack contains the F/8 risley prisms and the rotator power(JHA-6).
8.7.1 Push down on the safety lock that is on top of the left rail.
8.7.2 Slide the rack out until it stops.
8.7.3 Remove the risley prism cables which are: p2, p3, p4, p5, p6, p7, and a power
cable. Note: The power cable is with the box and it is plugged into the guide
probe power supply box. Attach a “to be removed” label to these cables.
8.7.4 Remove the rotator power box cables which are: p4, p5, p6, p8, and a power
cable. Note: The power cable is attached to the box. Attach a “to be removed”
label to these cables. P6 is permanently attached to the motor drive power
supply on rack 4.
8.7.5 Remove the safety lock that is on top of the left rail.
8.7.6 Use two workers to slide the rack out and place it on the cart.
8.8 The fourth rack contains the calibration light source power supply and the motor
drive power supply (Figure 2) (JHA-7).
Figure 2: Cass Cage to the Left of the Door
8.8.1 Push down on the safety lock that is on top of the left rail.
8.8.2 Slide the rack out until it stops.
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8.8.3 Remove the calibration light cables which are: p1, p2, p3, and a power cable.
Note: The power cable is with the box and it is plugged into the guide probe
power supply box. Attach a “to be removed” label to these cables.
8.8.4 Remove the motor drive cables that are on the other end of the p6 cable from
the rotator power box and a power cable. Note: The power cable is attached
to the box. Attach a “to be removed” label to these cables.
8.8.5 Remove the safety lock that is on top of the left rail.
8.8.6 Use two workers to slide the rack out and place it on the cart.
8.9 The fifth rack is the ICCD sync generator (Figure 3) (JHA-8). Note: This rack is not on
rails. Therefore, it will not slide out.
Figure 3: ICCD Sync Generator
8.9.1 Remove all of the connectors on the front panel. Note: Attach a “to be
removed” label to these cables.
8.9.2 Disconnect the cables that are on the back of the rack. These cables are: ICCD
y, ICCD x, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, and a power cord. Note: The
power cable is with the box. Attach a “to be removed” label to these cables.
8.9.3 Use two workers to hold up the rack, unbolt it, and place it on a cart.
8.10 The sixth rack is the F/8 servo amps, the F/8 controller, and an AC powered Ethernet
switch (Figure 4) (JHA-9).
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Figure 4: Cass Cage to the Right of the Door
8.10.1 Push down on the safety lock that is on top of the left rail.
8.10.2 Slide the rack out until it stops.
8.10.3 Remove the F/8 servo amp cables which are: p1, p2, p3, p4, p5, p6, p7, and a
power cable. Note: The power cable is with the box. Attach a “to be removed”
label to these cables.
8.10.4 Remove the F/8 controller cables which are: p1, p2, p3, p4, p6, p7, p8, an
Ethernet cable that is labeled F/8 baytech, and a power cord. Note: The
power cable is with the box. Attach a “to be removed” label to all of these
cables except for the Ethernet cable that is labeled F/8 baytech. P8 is a db9
cable that is hanging out of the box. The F/8 controller chassis needs to be slid
forward to disconnect the F/8 baytech Ethernet cable.
8.10.5 Remove the AC powered Ethernet switch cables. Note: These are the AC
cables that go to 4MAPS, PMTC, wavefront, F/8 amps, and F/8 control.
8.10.6 Remove the safety lock that is on top of the left rail.
8.10.7 Use two workers to slide the rack out and place it on the cart.
8.11 The seventh rack is the N2 and the wavefront camera control (JHA-10).
8.11.1 Push down on the safety lock that is on top of the left rail.
8.11.2 Slide the rack out until it stops.
8.11.3 Disconnect the three N2 hoses from the three flow gauges.
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8.11.4 Remove the wavefront camera control cables which are: p6 (db9, female), p7
(db9, male), p8 (db25, male), p1, p3, p4, p2, p5, and a power cord. Note: The
power cable is with the box. Attach a “to be removed” label to these cables.
8.11.5 Remove the safety lock that is on top of the left rail.
8.11.6 Use two workers to slide the rack out and place it on the cart.
8.12 The eighth rack is the PMTC and 4MAPS (JHA-11).
8.12.1 Push down on the safety lock that is on top of the left rail.
8.12.2 Slide the rack out until it stops.
8.12.3 Remove the PMTC cables which are: p1, p2, p3, p6, p7, p8, p9, p10, and a
power cord. Note: The power cable is with the box. Attach a “to be removed”
label to these cables. These cables will be reinstalled, so ensure the existing
labels are readable. If they are not, create a new label and put it on the cable.
8.12.4 Slide out the PMTC chassis and remove the cable on that inside that says
PMTC.
8.12.5 Remove the 4MAPS cables which are: p1, p2, p3, p5, p6, p7, p8, p9, p11, p12,
p13, and a power cord. Note: The power cable is with the box. Attach a “to be
removed” label to these cables. These cables will be reinstalled, so ensure the
existing labels are readable. If they are not, create a new label and put it on
the cable.
8.12.6 Remove the safety lock that is on top of the left rail.
8.12.7 Use two workers to slide the rack out and place it on the cart.
8.13 Disconnect the remaining connectors and cables. Remove the cables that go
through the sides of the Cass cage and tie them back and out of the way so the Cass
cage can be removed (JHA-12).
8.14 There are four patch panels on the North side of the cage that needs to be removed
(JHA-13). The cables in the front must be removed first, the panels must be removed
second, and the connectors on the panels must be removed last (Figure 5).
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Figure 5: North Side of Cass Cage
8.14.1 F/8 Servo Encoding I/O:
8.14.1.1 Disconnect channels a, b, and c on the front. Note: Attach a “to be
removed” label to these cables.
8.14.1.2 Disconnect a, b, c, and d on the back. Note: Attach a “to be
removed” label to these cables. These are all db9 connectors.
8.14.2 CCNS:
8.14.2.1 Remove p3, p10, and p13. Note: Attach a “to be removed” label to
these cables.
8.14.3 ACCNS:
8.14.3.1 Remove p31, p32, and p37. Note: Attach a “to be removed” label to
these cables.
8.14.4 ACOR:
8.14.4.1 Remove the four screws that attach the panel. Disconnect p31, p32,
p33, p36, p37, p38, p34, p35, p40, and p41.
8.15 Remove the six fiber pairs from the PF fiber optic box (JHA-14).
8.16 Remove the six fiber pairs from the IR fiber optic box (JHA-15).
8.17 Disconnect the main N2 line that is feeding down into the cage (JHA-16). Note: There
is a disconnect outside of the cage on the SW side.
8.18 Disconnect the PMTC RTD cable and feed it out of the cage (JHA-17).
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8.19 In preparation for feeding the cables through the cage so they are outside of it, the
cables must have the cable ties that secure them to the cage removed. Note: There
are also bundles of cables with tags on them that do not get removed.
8.20 Use two workers to feed the cables through the sides of the cage (JHA-18).
8.20.1 Two workers must be hooked up to the safety retractors inside the cage.
8.20.2 One worker must sit in the horseshoe and hook up to one of the straps that
are hanging from the telescope truss.
8.21 Go up on the lift (JHA-19).
8.22 Disconnect the J30 cable (JHA-20).
8.23 Feed all of the cables through the sides of the cage (JHA-21).
8.23.1 The worker who is in the horseshoe will have to help pull the cables as the
other workers in the cage pass them out on the North side.
8.24 Tie all of the cables out of the way so that the Cass cage can be removed (JHA-22).
8.25 Hook in to the retractors on the underside of the cell (JHA-23).
8.26 Go up on the lift (JHA-24).
8.27 Locate the three loadcell cables that were connected to the 4MAPS chassis (JHA-25).
Feed them out of the cable run on the Southeast side. Note: In order to remove the
cables, cut the cable ties on the tie bases that are mounted on the weights. Tie the
cables to the bottom of each loadcell (Figure 6).
Figure 6: Gray Primary Mirror Load Cell Cables Wire-Tied to the Bottom of Loadcell
8.28 Locate the rotator brake cable, disconnect it, and feed it into the cell (JHA-26).
8.29 Locate the heidenhain encoder cable, disconnect it, and feed it into the cell (JHA-27).
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8.30 Disconnect the ADC cable inside the stack and feed it into the cell (JHA-28).
8.31 Disconnect the thermocouples in the stack and feed the free end into the cell (JHA-
29).
8.32 Disconnect the air hose inside the stack for the rotator brakes and feed the free end
into the cell (JHA-30).
8.33 Ensure all of the cables, wires, hoses, etc. are disconnected from the Cass cage (JHA-
31). Note: If any of these items are found, remove them and annotate what they are
and where they were located.
8.34 Go down on the lift (JHA-32).
8.35 Once down, all workers must hook their safety retractors to the net guide wire (JHA-
33).
8.36 Turn the telescope over to the team that is removing the primary mirror and have
them remove the cage. Note: Refer to the Mayall 4M Primary Mirror Removal and
Installation Procedure (2100-AD-015-0005) and its corresponding JHA.
8.37 Two workers are needed to remove the three dial indicators.
8.38 Hook into the retractors on the underside of the cell (JHA-34).
8.39 Go up on the lift (JHA-35).
8.40 Disconnect the two wires from each switch and feed them into the mirror cell to
ensure they are out of the way (JHA-36).
8.41 Remove the dial indicators from the cell (Figure 7) (JHA-37).
Figure 7: Primary Mirror Dial Indicator and MAPS Lift Off Switch
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8.42 Turn the telescope over to the team that is removing the primary mirror. Note: Refer
to the Mayall 4M Primary Mirror Removal and Installation Procedure (2100-AD-015-
0005) and its corresponding JHA.
9.0 Procedure Review This procedure must be reviewed by employees under the following terms:
9.1 Initially
9.2 When there is a change in any of the job processes
9.3 When there is a change in a worker’s status, or job title
9.4 When governing authorities (such as OSHA) make changes
10.0 Records The records that must be kept on file by the supervisor are listed below. Training records
must be available and maintained for a minimum of five years.
10.1 Daily Briefing Form Signature Page(s)
10.2 JHA Signature Page(s)
10.3 Personnel Training Records:
10.3.1 Fall Protection
11.0 References DOCUMENT NUMBER DOCUMENT TITLE
1000-AD-015-0003 Fall Protection Plan SOP
1000-AD-015-0004 Rescue Plan SOP
2100-AD-015-0005 Mayall 4M Primary Mirror Removal and Installation Procedure
2100-AD-015-0005-JHA Mayall 4M Primary Mirror Removal and Installation Procedure