• Topic ID: id_23554309
  • Version: 1.0
  • Date: Oct 9, 2018 1:42:15 PM

Inverter Replacement

Prerequisites

Overview

To replace the HP Inverter in the X-Ray generation sub-system:

  • If possible, save JEDI runtime parameters

  • Remove Auxiliary Box

  • Replace Inverter

  • Reinstall Auxiliary Box

  • Reload JEDI software and appropriate database

  • Run Filament Calibration

  • Verify system is operational

1 HP Inverter Removal

Procedure

  1. Save JEDI runtime parameters.

    In most cases you will want to perform this step, however it may not be possible, depending on the failed inverter component. If it is not possible, move on.

    • warning
    • Potential for ShocK.
    • Voltage may be present.
    • Use proper lockout/tagout procedures before replacing components.
  2. Remove power to the gantry using proper Lockout / Tagout procedures.
  3. Remove gantry side, top, and front covers.
  4. Turn OFF all three switches (AXIAL DRIVE ENABLE, HVDC ENABLE, 120 VAC) on the Service Switch Panel.
  5. Remove EMC Box cover between Inverter and Tank.
  6. Remove the Auxiliary Box, using the Auxiliary Box Replacement (Pro 16) procedure.
    note:

    With power removed to the gantry, removing the aux box will not cause the gantry to rotate.

  7. Remove JEDI HP Inverter.
    1. Rotate the gantry such that Inverter assembly is in the 2:30 O'clock position.
    2. Lock the gantry in position, using the rotational lock. Ensure that gantry rotation is locked by attempting to rotate the gantry by hand.
    3. Remove three HV cable clamps from front of aux box. These are not part of the Inverter assembly so keep the hardware.
    4. Remove the inverter covers.
    5. Attach an ESD wrist strap to protect internal circuitry.
    6. Disconnect all wire connections from HP Inverter. Keep any hardware associated with the wiring. These include:

      • DAS (J2)

      • HV Tank measure cable (J12)

      • HV Inverter/Tank cable (inverter to tank) - disconnect inside inverter. Make sure to remove nut and washer.

      • HVDC wire (connects inside inverter, coming from choke assembly). Make sure to remove the nut(s) and washer(s).

      • Aux harness

        • DC bus Aux (J6)

        • LVPS supply (J1)

        • Filament control (from Aux Box to HV tank - clamped to inverter)

      • Smart Tube ID (J5)

      • CAN Aux (J13)

      • Sys CAN (J3)

    7. Insert the lifting post and attach the boom and hoist.
    8. Connect the hoist hook to the Inverter lifting point. Remove all slack in the chain and apply light tension.
    9. Remove the four (4) long M12 bolts that hold the inverter chassis to the gantry.
    10. Lightly reattach the covers on the inverter. This will ensure the bolts and the washer are captured and do not fall into the gantry, as they are difficult to reach. You do not need to retrieve these bolts, as you will use the new ones supplied with the new inverter.
      note:

      If new bolts are not supplied, then the old bolts WILL need to be retrieved for reuse. Make certain to thoroughly clean all dried loctite from the bolts.

  8. Carefully swing the inverter free from the gantry.
  9. Remove the back side of the EMC Box. Keep for new inverter.

2 HP Inverter Installation

Procedure

  1. Ensure that tagout / lockout procedure has been applied, and that gantry power is removed.
  2. Ensure that gantry rotational lock is engaged and gantry does not rotate by attempting to rotate gantry by hand.
  3. Attach the back of the EMC box (from old inverter) to the new inverter.
  4. Using the hoist, attach new inverter to gantry. As you lower the inverter, watch to ensure that the EMC box is in place (The pad on the back of the EMC box rests on the tank). Then, as you lower the inverter, it will fall into place.

    Use the supplied new bolts, with loctite 242 (blue) for mounting.

    If new bolts are not supplied, clean all dried loctite from the existing bolts and apply new blue loctite (242).

  5. Remove inverter covers.
  6. Apply initial “preload” torque to M12 mounting bolts:
  7. Apply final torque to the M12 inverter ‘mounting bolts:
  8. Remove boom/post/hoist.
  9. Reconnect the HVDC wires from the choke assembly to the inverter.
  10. Disengage rotational lock.
  11. Reattach all cable connections:

    • Aux harness

      • DC bus Aux (J6)

      • LVPS supply (J1)

      • Filament control (from Aux Box to HV tank - clamped to inverter)

    • Smart Tube ID (J5)

    • CAN Aux (J13)

    • Sys CAN (J3)

    • DAS (J2) and ground clamp.

    • Route HV inverter/tank cables according to HV Cable Routing (Pro16) procedure

    • HV Tank measure cable (J12)

  12. Replace Inverter covers.
  13. Replace EMC Box cover between Inverter and HV Tank.
  14. Reattach 3 HV cable hooks to front of inverter.

3 Finalization

Procedure

  1. Perform Gantry Rotation Safety Check.
  2. Perform Gantry Balance Procedure.
  3. Run JEDI Noise Test (Pro16, RT)
  4. Download JEDI firmware using Flash Download Tool.
  5. Reset generator Tracking and Trending (TnT) Data (see JEDI Generator Tool (Pro16)).
  6. Meter Verification (Pro 16).
  7. HV Tank Feedback Resistor Verification (Pro 16) (bleeder test).
  8. Restore JEDI Runtime Parameters, if you saved Runtime Parameters from the old inverter (see JEDI Generator Tool (Pro16)). If you did not save runtime parameters from the old inverter, skip this step.
  9. Perform Filament Calibration
  10. CT Number Check.
  11. Perform System Scanning Test.
  12. Perform Quality Assurance Test.
  13. SaveState