LCA-18062 Carousel Maintenance Plan Page of
Document # LCA-18062 | Date Effective | Status | |
14 – Septembre – 2019 | Draft 1 | ||
Author(s) | |||
Guillaume Daubard, Claire Juramy, Didier Laporte, Pierre Antilogus | |||
Camera Technical Note | |||
Subsystem/Office | |||
Filter Exchange System | |||
Document Title | |||
Carousel Maintenance Plan | |||
Revision | Effective Date | Description of Changes |
Draft 1 | September14th, 2019 | Initial draft |
Regular evaluation to trig a maintenance 4
carousel rotation diagnostic 4
Carousel Slip-ring collectors 4
Carousel Driving Motor assembly replacement 6
Carousel Brake assembly replacement 6
Carousel Driving pinion replacement 6
Lubrication : Carousel gear box 7
Carousel Brake Only replacement 8
Carousel Encoder Head replacement 8
Carousel Driving control assembly replacement 8
Carousel clamp actuator assembly replacement 8
Carousel clamp control assembly replacement 8
Carousel Brake telemetry assembly replacement 8
Carousel Temperature telemetry assembly 8
Carousel Brakes relay assembly 8
Carousel Brakes power assembly 8
Carousel Standby socket target assembly 8
Carousel backflange cables (all cables) 8
Carousel X- clamp system (with sensors and clamp unclamping assembly) 8
Carousel X+ clamp system (with sensors and clamp unclamping assembly) 8
Carousel Z+ Vguide clamp assembly 8
Carousel Filter socket sensor assembly 8
Carousel Slip-ring collectors 8
Carousel filter cables assembly 8
Carousel control/command device (Safety PLC + shunt regulator + Safety relays) 8
Free the carousel rotation & Release the break without FCS 9
Unlock a filter pin stuck in a broken clamp prior to replace the clamp 10
n°. | Title |
[1] | LCA-282 – Camera Operations Concept Document |
[2] | LCA-16589 – Camera Maintenance Use Cases and Activities |
[3] | LCA-10827 – Filter Exchange System Maintenance Plan |
[4] | LCA-XXXX – Carousel Assembly Plan |
CCS | Camera Control system |
FCS | Filter Control System |
HCU | Hardware Control Unit |
CPPM | Centre de Physique des Particules de Marseille |
The document deal with all the maintenance operations which will be done on the Carousel. The use cases are defined in the various configurations and for the different types of maintenance.
It is given the list of spares which can be used for repairing or for the scheduled components changes.
The mechanical parts and associated motors/break for the main carousel functions, rotation to present the right filter to the Auto Changer, and lock/unlock a filter, have been designed such that no replacement are needed for a standard usage.
Still there is a
For each use case we consider three types of maintenance :
The scheduled maintenance for the systematic operation : the inspection, the lubrication or the replacement of the components in respect with the defined lifetime.
The Conditional or the predictive maintenance that will be operated from a particular event. For examples, an unusual signal, the increasing of the current, or an earthquake.
The corrective maintenance for the troubleshooting after any hardware or software failure
The detailed operations will be described in the next section
Filter pin should not age, but unexpected choc ( like earthquake, see corresponding section in this document , or a bad operation ) may mark them . Beyond action after earthquake, each time a filter is extracted from the camera a visual inspection of the pin should be performed. If it has a strong mark the decision to replace it can be taken , but also its associated clamp in the carousel should be maintained/inspected ( dismounted and inspected) to understand the origin of the mark .
All the carousel pin should be inspected at each main camera maintenance ( ~ 1year ½ ? ).
It is recommended to take a picture of the pin to track even small marks on each pin.
To verify the carousel functional capabilities, or to diagnose any default, the carousel can be controlled in a stand-alone mode. The stand-alone mode allows to individually drive each element of the system.
The carousel can be controlled with or without the Local Protection Module. An engineering key allows to shunt the Local Protection System and to run elementary operations.
Except the filter pins which need to be replaced with the filter in clean room, all replacement/intervention have to be performed on the camera directly (in the backflange/carousel area )
Pictures :
TBD
Maintenance frequency :
The motor is friction less , and is designed to run for years continously. So with an usage of few minutes a day at maximum, it should be able to run for the full length of LSST without replacement .
Detection of a requested maintenance :
TBD : Analysing the power consumption and temperature during filter exchange or full carousel rotations, may be an indication of an abnormal motor behavior and could trig a motor inspection/replacement.
Operation for the replacement of the assembly :
TBD
Pictures :
TBD
Maintenance frequency :
Brake should be able to run for the full length of LSST without replacement .
Detection of a requested maintenance :
TBD
Operation for the replacement of the assembly :
TBD
Pictures :
TBD
Maintenance frequency :
The frequency of lubrication has still to be determined. It is expected that it will be at a lower frequency than the scheduled maintenance period.
Detection of a requested maintenance :
TBD : Analysing the power consumption during filter exchange and the fft of full carousel rotations, should allow to identify an increase in friction , the identification of the issue / which rotating part is involved in the performance degradation , is still under investigation.
Maintenance description :
TBD
Pictures :
TBD
Maintenance frequency :
The frequency of lubrication has still to be determined. It is expected that it will be at a lower frequency than the scheduled maintenance period.
Detection of a requested maintenance :
TBD : Analysing the power consumption during filter exchange and the fft of full carousel rotations, should allow to identify an increase in friction , the identification of the issue / which rotating part is involved in the performance degradation , is still under investigation.
Maintenance description :
TBD
Pictures :
TBD
Maintenance frequency :
The frequency of lubrication has still to be determined. It is expected that it will be at a lower frequency than the scheduled maintenance period.
Detection of a requested maintenance :
TBD : Analysing the power consumption during filter exchange and the fft of full carousel rotations, should allow to identify an increase in friction , the identification of the issue / which rotating part is involved in the performance degradation , is still under investigation.
Maintenance description :
TBD
Filter pin should insensitive to normal running and should not age. Still in case of a major earthquake or due to an unexpected choc, they may need to be replaced ( see other section on filter pins in this document) .
Traveler Document on how to replace a filter pin : LCA-xxxx (TBD) + LCA-18086 ( add a washer on filter interface for X-)
In case of a major issue or for maintenance operation , you may have to free the carousel rotation directly , without using the FCS. This is a dangerous operation , as the carousel in case of an unbalance load may turns . This has been used for example with the camera at 90 or -90 deg (=insensitive to unbalance load) to turn by hand the carousel (~ 35 kg of traction ) to check that the carousel was able to move.
Associated traveler Document : LCA-18150
In case of earthquake and following the measured magnitude, it will be necessary to check the following elements :
Filter pin can impacted by earthquake generating an acceleration above 3g (see LCA_17505), we recommend a comparison of the clamp probes sensitive to the pin position/distortion and a visual inspection of all pins.
As quoted in LCA-17505 , filter pins should show :
● No-plastic deformation for an acceleration of 3.7 g and bellow.
● Plastic deformation start above ~ 3.7 - 3.7g + 20% . So in case of major seismic event with possible acceleration above 3.7g , the recommendation will be to replace all filter pins.
● No pin break under a load of 3.7g + 66 % (~6g). Notice that this resistance, implies that the filter angular movements are limited by the pins guided by the clamps. If one filter pin is not guided (outside its clamp), the angle between other pin and the clamp ball can be bigger than the value considered here, so a force larger than the one considered here could be applied for a given filter mass.
In practice we recommend a visual inspection of the filter pin when a filter is outside the camera / once a year
If a pin present a choc it should be replaced and its associated clamp as well .
Carousel can be rotated at low speed and consumption should be checked . An fft analysis of current & speed data from the controller will be able to identify small defect. Still in case of large earth quake , it will be preferable to perform first a visual inspection of all Carousel driving pinions.
A clamp removed from the carousel due to incident or hearth quake , can be maintained /fixed /qualified . A documentation as to be written (TBD) . The preferred option at this stage will to send it at LPNHE.
In case an internal part brakes inside a clamp and prevent to unlock a pin/filter , the pin stuck in the clamp will have to be unscrewed from the filter with the filter still hold by the auto-changer.
The method will imply to unscrew the pin from the filter as the auto-changer is moved away from the carousel by small steps ( ~1-2 mm).
The exact procedure will be developed on the long run demonstrator , a dedicated tools set and FCS command has still to be implemented and tested.
