• Topic ID: id_17423037
  • Version: 4.0
  • Date: Jan 20, 2020 8:32:00 PM

Thermistor Assembly Replacement

Prerequisites

Overview

This procedure defines the necessary steps to Remove and Install the Thermistor Assembly.

1 Preparation

Procedure

  1. Move table to home position, fully out and down.
  2. Remove right side gantry cover.

    Refer to Parts Replacement → Gantry → Enclosure → (Cover Removal Procedure).

  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. Position the detector at 12 o'clock and lock gantry rotation.
  6. Turn OFF the 120 VAC switch on the gantry’s Service Switch Panel.
  7. Remove the gantry left side cover, top covers and front cover.

2 Replacement Procedure (Low Channel Side)

2.1 Removal Procedure

Procedure

  1. Remove 4 screws, and remove the assembly cover.

    Figure 1. Thermistor Assembly Cover Removal

  2. Disconnect all cable connector from the thermistor assembly.
  3. Remove 4 studs and 2 screws, and remove the thermistor assembly.

    Figure 2. Thermistor Assembly Removal

2.2 Installation Procedure

Procedure

  1. Install the new thermistor assembly into place.
  2. Fix the thermistor assembly using the 2 screws and 4 studs.
  3. Reconnect all cable connector.
  4. Install the assembly cover using the 4 screws

3 Replacement Procedure (High Channel Side)

3.1 Removal Procedure

Procedure

  1. Engage gantry rotational lock.
  2. Remove HV cables to HEMIT tank and remove HEMIT Tank assembly to access screws for thermistor assembly cover. Refer to HEMIT Tank Replacement.
  3. Remove 4 screws, and remove the assembly cover.

    Figure 3. Thermistor Assembly Cover Removal

  4. Disconnect all cable connector from the thermistor assembly.
  5. Remove 4 studs and 2 screws, and remove the thermistor assembly.

    Figure 4. Thermistor Assembly Removal

3.2 Installation Procedure

Procedure

  1. Install the new thermistor assembly into place.
  2. Fix the thermistor assembly using the 2 screws and 4 studs.
  3. Install the assembly cover using the 4 screws
  4. Reconnect all cable connector.
  5. Install HEMIT tank and connect HV cables. Refer to HEMIT Tank Replacement.
  6. Restore gantry rotational lock.

4 Gantry Reassembly

Procedure

  1. Make sure the Axial Drive, HVDC and 120 VAC switches on the gantry’s Service Switch Panel are OFF.
  2. Release the gantry rotational lock and install gantry covers, all except the right side cover.

    Refer to Replacement → Gantry → Enclosure → (Cover Removal Procedures).

  3. Turn on the 120 VAC, HVDC and Axial drive service switches.
  4. Install gantry right side cover.

5 Finalization

No finalization steps.