Difference between revisions of "For the second coil"

Revision as of 11:52, 19 January 2011

• Action Items

• • Wiring
    • remove jumper box and cables and bring to F117 for rework - done
    • remove current-limiting resistor boxes, bring to F117 for rework - done
    • minimize summed coil voltage readouts, do most sums in PLC
    • implement early-warning quench/overvoltage detection in PLC
    • add separate readouts of splice and vapor-cooled lead voltages
    • combine splice and lead into one hardware quench/overvoltage protection channel using Newport controller
    • match and balance all current-limiting resistors, go back to original 100k Ohm matched resistors
    • read out voltage taps for quench detection and DAQ using separate resistor chain
    • will not go to active isolation for the upcoming coil
    • may need active isolation if passive isolation does not work
    • may implement active isolation in the hall
    • update wiring diagrams to "as built"
    • get diagrams and spec sheets to Fernando
    • understand signal clipping and interaction between readout modules, test and replace if necessary
    • minimize noise

• • Danfysik power supply
    • understand ramp-down mechanism
    • UPS on Danfysik boards and contactor
    • measure fast dump resistors in power supply - done
    • eliminate 2V DC offset
    • fix slow dump - done
    • make more copies of full Danfysik power supply manual (get from Steve L)

• • Danfysik quench detector
    • match and balance resistors
    • revert channels used for splice/leads to normal coil balance mode
    • install test points for gain/offset tuning
    • install pots for external balance if unable to eliminate DC offset
    • note that max ramp rate in the hall is 10V / 20H = 0.5 A/sec

• • USB device
    • install voltage dividers to extend voltage range
    • rework Zener protection circuit

• • automated elog entries

• • A-B HMI improvements
    • additional HMI license, get second computer working
    • dual-redundant HMI server or another machine for the server
    • HMI development machine and license
    • contact A-B salesman about licenses
    • change HMI database to MySql
    • more pre-defined trend plots
    • more HMI screens (may need license upgrade)
    • simplify existing screens
    • better indication of what caused fast/slow dump

• • A-B PLC program improvements
    • simplify many operations
    • improve PLC early problem detection
    • improve PLC cryo control under varying CTF operating conditions

• • improve cryo system
    • minimize ice buildup
    • more heating/insulation on N2 vent line
    • do we need cold traps?
    • do we need additional valves, check valves, bypasses, whatever?
    • can we calibrate the C-glass sensors somehow?

• Basic questions
  • what is causing blockage in vapor-cooled lead?
    • broken valve!
  • lag between field and current...are there turn-to-turn shorts in coil 1?
    • maybe short, maybe eddy currents
  • what worked, what didn't for coil 1?
  • what should we do differently for the next coil?
    • will we open up coils 3 and 4?
  • what might we consider doing differently in the hall?
  • do we want an independent review of our fast (and slow) dump strategy and system?
  • have we documented our experience?
  • sub-coil inductances
    • measure with inductance meter on the platform
    • inductance seen on splices
  • did we ever implement guard shack notification?