• Topic ID: id_23554412
  • Version: 2.0
  • Date: Sep 26, 2020 10:13:01 PM

No Load kV Test (Pro, RT, VCT)

Prerequisites

Overview

The No Load kV test is a pass / fail test. The purpose of this test is to verify that the HV power inverter and HV tank are working properly. This test is used when the X-Ray Generation subsystem becomes difficult to diagnose because this test allows for the separation of the HV tank and X-Ray tube by operating with or without the HV candlestick plugged into the HV tank (see Notice). Thus, this test requires manual operation. A summary of the procedure is provided below:

  • Run the test via software with HV Candlestick connected. If test passes, the test will not fail when HV cable is disconnected, thus the test is finished.

  • Remove HV Candlestick from tank receptacles

  • Fill tank receptacle with oil

  • Run diagnostic

  • Clean up

Procedure

  1. First run the no-load kV test with the tube connected. This will not harm the system. If it passes, move on to the next troubleshooting step. If the test FAILS, continue performing the procedure to isolate between tank and tube.
    • warning
    • Potential for ShocK.
    • Voltage may be present.
    • Use proper lockout/tagout procedures before replacing components.
  2. If needed, remove gantry side and front covers
  3. Remove HV cable candlestick from tank receptacle.
    4. Notice Image
    • notice
    • Equipment damage possible. You must fill the receptacle with oil to avoid arcing.
  4. Fill tank receptacle with oil.
  5. Power on the generator using 120VAC Enable and HVDC Enable switches on the service switch panel. Also press ESTOP DRIVES RESET.
  6. If desired, at this point you may check the following:
    1. HVDC input to the Inverter in an acceptable range: 380 to 750 VDC
    2. PPC control board working: S0-S7 LEDs are lit successively or a combination of them blink
  7. Launch the GENERATOR TOOL. See tools section for more information.
  8. Launch the No Load kV Diagnostic tool.
  9. Run the diagnostic.

Finalization

  1. It may be necessary to combine the results of the No Load kV test with the two other major JEDI tests (Shorted Inverter / Gate Command tests). This is because the Inverter and Auxiliary Box control the HV tank and Tube and problems in either the Inverter or Aux Box could cause the No Load kV test to fail. However, on its own, the No Load kV test can indicate:
    1. No Load kV test FAILS (with Candlestick disconnected) - likely HV Tank problem
    2. No Load kV test first FAILS (with Candlestick connected) then PASSES (with Candlestick disconnected) - likely X-Ray tube problem.