• Topic ID: id_15460247
  • Version: 2.0
  • Date: Nov 8, 2018 1:38:31 AM

High Voltage Tank Replacement

Prerequisites

Overview

This document provides the necessary steps to replace and configure the High Voltage Tank for imaging.

1 High Voltage Tank Removal

Procedure

  1. Move table to home position.
  2. Remove right side gantry cover.
  3. Turn off HVDC ENABLE, AXIAL DRIVE ENABLE, and 120 VAC ENABLE switches on Service Switch Panel.
  4. Remove power to system. See Equipment Service - Lockout-Tagout-PPE from Safety section.
  5. Remove scan window, gantry left side cover, gantry top covers and gantry front cover.
  6. Rotate gantry such that EMC Box cover, between Inverter and High Voltage Tank, can be easily removed. (See Item 1 in Figure 1)

    Figure 1. EMC Box Cover

  7. Remove EMC Box cover between Inverter and High Voltage Tank with a 3mm Allen Wrench ( See Item 1 in Figure 1).
    note:

    Keep M4 screws and washers.

  8. Rotate gantry such that High Voltage Tank lower mounting bolts are accessible for removal (See Figure 2).

    Figure 2. High Voltage Tank Mounting Bolt Locations

  9. Remove two High Voltage Tank lower M12 mounting bolts with 10mm hex bit socket drive and 12 inch extension.
    note:

    If bolts are supplied with new High Voltage Tank, throw away old bolts.

    note:

    If bolts are not supplied with new High Voltage Tank, reuse existing bolts.

  10. Rotate gantry such that High Voltage Tank is in 2:30 o'clock position.
  11. Engage rotational lock. See Equipment Service - Lockout-Tagout-PPE from Safety section.
  12. Cut Ty-wraps on Inverter and Auxiliary Box clamps and remove High Voltage cable from clamps.
  13. Loosen High Voltage cable locking ring with spanner wrench.
  14. Remove High Voltage cable candlestick and place a cover over candlestick.
  15. With Dry Wipes, soak up the oil in the High Voltage Tank receptacle.
  16. Place a cap or paper towel in top of receptacle to prevent residual oil spillage and dirt from contaminating receptacle.
  17. Remove Inverter EMC Box cover bracket with a 3mm Allen Wrench (See Item 1 in Figure 3).
    note:

    Keep M4 screws and washers.

    Figure 3. EMC Box and Cover Bracket

  18. Remove EMC Box (white nylon) top cover on High Voltage Tank, with a flat blade screw driver, to expose High Voltage cable terminals (See Item 2 in Figure 3).
  19. Detach High Voltage Inverter/Tank connections from EMC Box terminals with a 13mm hex socket drive.
    note:

    Keep washers and nuts.

  20. Disconnect J12 connector and remove cable clamp from High Voltage Tank with a 3mm Allen Wrench (See Item 1 in Figure 4)
    note:

    Keep clamp hardware.

    Figure 4. High Voltage Tank Electrical Connections

  21. Disconnect J4 connector and remove cable clamp from High Voltage Tank with a 3mm Allen Wrench (See Item 2 in Figure 4)
    note:

    Keep clamp hardware.

  22. Insert lifting post into gantry frame and attach boom and hoist.
  23. Connect hoist hook to High Voltage Tank lifting point.
    note:

    Remove all slack in chain and apply light tension.

  24. Remove two High Voltage Tank upper M12 mounting bolts with 10mm hex bit socket drive and 12 inch extension.
    note:

    If bolts are supplied with new High Voltage Tank, throw away old bolts.

    note:

    If bolts are not supplied with new High Voltage Tank, reuse existing bolts.

  25. Using hoist, carefully lift and swing High Voltage Tank free of gantry and lower to floor towards gantry right side.
  26. Detach hoist hook from High Voltage Tank lifting point.

2 High Voltage Tank Installation

Procedure

  1. Place new High Voltage Tank crate near gantry front-right side and open top of crate.
  2. Attach hoist hook to new High Voltage Tank lifting point.
  3. Using hoist, carefully lift new High Voltage Tank out of crate, swing to front of gantry and position over gantry two guide pins.
  4. Fasten High Voltage Tank to gantry by inserting four M12 mounting bolts and washers with a 10mm hex bit socket torque wrench and 12 inch extension (See Figure 2)
  5. Tighten each M12 mounting bolt to the following pre-torque value.
  6. Detach hoist hook from High Voltage Tank lifting point.
  7. Attach hoist hook to old High Voltage Tank lifting point.
  8. Lift old High Voltage Tank into crate, detach hoist hook from lifting point, and prepare for storage/shipping.
  9. Remove hoist/boom/post assembly from gantry.
  10. Apply the final torque to the M12 mounting bolts.
  11. Route and connect J12 connector to High Voltage Tank (See Item 1 in Figure 4)
  12. Apply Loctite 242 to 3mm screw and attach cable clamp to High Voltage Tank with a 3mm Allen Wrench. Torque to same values as step 22 below.
  13. Route and connect J4 connector to High Voltage Tank. (See Item 2 in Figure 4)
  14. Attach cable clamp to High Voltage Tank with a 3mm Allen Wrench.
  15. Route and attach High Voltage Inverter/Tank cable to High Voltage Tank EMC Box terminals.
    note:

    Use washers and nuts from Section 4.1.

  16. Tighten mounting nuts with a 13mm hex bit socket torque wrench, to the following torque values.
  17. Install EMC Box (white nylon) top cover on High Voltage Tank and tighten each captive screw with a flat blade bit torque driver to 0.45 N-m or 4.0 lbf-in.
  18. Install Inverter EMC Box cover bracket and fasten with four M4 washers and screws from Section 4.1.
  19. Tighten each M4 screw with a 3mm hex bit socket torque wrench, to the following torque values.
  20. Install EMC Box cover between Inverter and High Voltage Tank and fasten with four M4 washers and screws from Section 4.1.
  21. Tighten each M4 screw with a 3mm hex bit socket torque wrench, to the following torque values.
  22. Perform Securing HV Cable.
  23. Restore power to system. See Equipment Service - Lockout-Tagout-PPE from Safety section.
  24. Turn on 120 VAC ENABLE, AXIAL DRIVE ENABLE, and HVDC ENABLE switches on Service Switch panel.
  25. Press ESTOP RESET on Service Switch panel and wait until scan hardware is reset.

3 Setup, Checks, Alignments, and Calibrations

Procedure

  1. Reset TnT
  2. Gantry Rotation Safety Check
  3. Gantry Balance
  4. Meter Verification
    note:

    (For GE Healthcare Personnel Only) For supported software releases, perform High Voltage Tank Feedback Resistor Verification (Restricted) and Internal Scan Timer Verification (Restricted) procedures instead of High Voltage Tank Feedback Resistor Verification procedure.

  5. High Voltage Tank Feedback Resistor Verification
  6. Turn off HVDC ENABLE, AXIAL DRIVE ENABLE, and 120 VAC switches on Service Switch panel.
  7. Install gantry front cover, gantry top covers, gantry left side cover and scan window.
  8. Turn on 120 VAC, AXIAL DRIVE ENABLE, and HVDC ENABLE switches on Service Switch panel.
  9. Press ESTOP RESET on Service Switch panel and wait until scan hardware is reset.
  10. Install right side gantry cover.
  11. Filament Calibration
  12. HHS Scans