• Topic ID: id_17423043
  • Version: 3.0
  • Date: Apr 22, 2019 12:56:26 AM

Gantry Heater Replacement

Prerequisites

Overview

This procedure defines the steps necessary to replace the gantry heater/blower assembly.

Procedure

  1. Move table to its lowest elevation.
  2. Remove gantry right side cover.

    Refer to Parts Replacement > Gantry > Enclosure > (Cover Removal Procedures).

  3. 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.
  4. Turn OFF the Axial Drive and HVDC switches on the gantry’s Service Switch Panel.
  5. Rotate the gantry by hand to gain clear access to the heater assembly. Position the tube at approximately 9 o'clock which will have the weight stack above the detector at the 3 o'clock position behind the service switch panel.
  6. Turn OFF the 120 VAC switch on the gantry’s Service Switch Panel.
    • danger
    • Electrocution hazard.
    • High Voltage present.
    • Turn off HVDC. Use proper lockout/tagout procedures before servicing components.
  7. Perform all required LOTO activities to remove all power to the gantry.
  8. Remove the gantry left side cover, top covers and front cover.
  9. Remove the gantry tilting assembly bottom cover.
  10. The heater has an air intake filter on the left side. See Figure 1.

    Figure 1. Air Intake Filter

  11. Remove the 3 screws in the front by the latch using a 5 mm hex wrench. See Figure 2.

    Cj M40 uses different blower, but screw location is same.

    Figure 2. Heater Screws (Cj Phase 2.5)

    Figure 3. Gantry Heater Mounting Screws

  12. Remove the 3 screws on the inside plate that holds the heater to the plate using a 5 mm hex wrench.
  13. Slide the heater forward and carefully remove all connecting cables.
  14. Carefully remove the heater assembly from the gantry.
  15. Install the new heater assembly by reversing the above steps. Install all hardware and cables.
  16. Torque the Heater assembly mounting screws to:
  17. Install the gantry tilting assembly base cover.
  18. Install the gantry front cover, top covers and left side cover.

    Refer to Parts Replacement > Gantry > Enclosure > (Cover Procedures).

  19. Remove LOTO and restore power to system.
  20. Enable 120 VAC HVDC and Axial Drive service switches from the service switch panel. Press the table drives enable button on the lower right corner of the service switch panel.
  21. Install the gantry right side cover.

Finalization

  1. Perform a System Scanning Test from the Functional Checks menu of the service manual to ensure system operation.