• Topic ID: id_16157508
  • Version: 4.0
  • Date: Jan 20, 2020 8:35:51 PM

Simplified HVDC Power Pan ASM Replacement

Prerequisites

Overview

This procedure defines the replacement process for the gantry simplified HVDC power pan assembly.

Figure 1. HVDC Power Pan ASM

1 Preparative

Procedure

  1. Move the table cradle to the home position.
  2. Stop the rotor of X-ray tube in case of Liquid Bearing Tube before HVDC off. Refer to Liquid Bearing Tube Rotor stop procedure for details.
  3. Remove the gantry right side cover and disable “Axial Drive”, “HVDC” and “120VAC” switches from the service switch panel.
  4. Remove the gantry left, top and rear covers, refer to Replacement > Gantry > Enclosure > Cover Removal Procedure.
  5. Shutdown the system by normal shutdown procedure, then turn OFF main power to system at A1 panel or PDB.
    note: If there is a UPS, switch OFF the UPS output.
  6. Apply proper Lockout / Tagout procedures to ensure all power is off to NGPDU.
  7. Remove the two rear base covers by referring Stationary Base Cover Removal and Reinstall.

2 HVDC Power Pan ASM Replacement

Refer to HVDC power pan schematic diagram for disconnecing internal/external interconnections. (Click on the PDF icon 2387385-3SCH_r1.pdf to open the power pan interconnections)

Procedure

  1. Mark and disconnect the HVDC power wires (3 wires) from TS1. (See Figure 2)
  2. Disconnect the Ethernet and optical fiber cables from the power pan bracket.

    Figure 2. HVDC, Ethernet, Optical Fiber and Ground wires Removal

  3. Mark and disconnect the 120VAC power wires (3 wires) from TS5. (See Figure 3)
  4. Mark and disconnect the two 440VAC power wires (4 wires) from TS2.

    Figure 3. TS2 and TS5

  5. Mark and disconnect the two 120VAC power wires (5 wires) from TS4.

    Figure 4. TS4

  6. Mark and disconnect all ground wires from the power pan bracket.
  7. Remove the HVDC power pan from the gantry frame by unscrewing four screws as shown below white circles.

    Figure 5. Screws Position

    Figure 6. HVDC Power Pan Removal (Example)

  8. Remove the HVDC power pan plastic cover by unscrewing its two screws.

    Figure 7. Plastic Cover Removal

  9. Disconnect the two DC wires shown as in Figure 8 and remove them from the HVDC power pan bracket.

    Figure 8. Disconnect DC wires

  10. Install the new HVDC power pan assembly and re-connect wires by referring to the reverse order of removal.

    Figure 9. HVDC Power Pan

3 Restore and Verify the System Power

Procedure

  1. Turn ON main power to system at A1 panel or PDB.
  2. Power on the system and verify the system is operating normally.
  3. Restore the gantry to original configuration.

4 Finalization

No finalization steps.