BELLE KLM HV Troubleshooting Summary

• Trip Report on August 19, 1998 meeting at LeCroy.

• Daily Reports

  • Thursday, August 20, 1998:Completed modification to all 1469Ns.

  • Friday, August 21, 1998: tried to call Jeff Cox, who was on vacation. Spoke to David Cozart and Alan Baker, who reported that the units were all modified seven 1469N one 1468P in walk-in oven. These will run for 16-20 days. Start of tests delayed by attempt to connect system to network. Decided to start tests using local computer. Units were placed in oven Thursday and tests started Friday AM. The 1469Ns were set to -3.5kv and the 1468P was set to +6kv.

  • Sat. August 22: 3 channels in the 1468P had tripped sometime during the previous night. Since we do not want to turn HV off under any circumstances, the 1468P was left in its tripped state.

  • Mon. August 24: The mainframe and the PC had rebooted itself sometime between 3PM Saturday and 8:30AM Monday (HV was OFF and the PC was at the DOS prompt). We believe this was due to a power glitch. We've taken this opportunity to re-initialize the 1468P. In the afternoon it was observed that one channel in BULK1 of a 1469N (S/N B51270) had a current reading of 0.01uA. We believe this current reading is due to a faulty load. There has been no sagging voltage on any unit.

  • Tues. August 25: No change in status.

  • Wed. August 26: No change in status.

  • Thurs. August 27: No change in status.

  • Fri. August 28: BULK2 on a 1469N (s/n B512671) tripped sometime between noon and 5:00PM. HV has been restored to this BULK. Channels 1 & 3 on a 1468P (s/n B51676) tripped some time between noon and 5:00PM. HV has been restored to these channels. These 2 units were in adjacent slots (7 & 8).

    There has been no voltage sag on any unit.

  • Mon. Aug. 31 Channels 1 & 3 on 1468P(s/n B51676) tripped sometime between 5:00PM on 8/28 and 8:00AM today. HV has been restored on these channels.

  • Tues. Sept. 1 Channels 1, 2 & 3 on 1468P(s/n B51676) tripped sometime between 12:00PM & 4:00PM.

  • Wed. Sept. 2 - No change in status. There has been no voltage sag on any unit.

  • Thurs. Sept. 3 - 1469N (s/n B51083) has developed a problem. The BULK2 current reading is -280uA, while the current readings in the eight channels for BULK2 is -42uA per channel. The correct current reading per channel should be -35uA.

    LeCroy believes that BULK2 has lost its calibration data. The system will not be shut down to re-calibrate the unit.

  • The next status report that you will receive will be on 9/8. David Cozart is taking tomorrow (9/4) off and LeCroy is closed for Labor Day.