• Topic ID: id_15460195
  • Version: 2.0
  • Date: Nov 8, 2018 1:38:24 AM

Gantry Top Covers & Fan Removal (Removable Fans)

Prerequisites

Overview

The Gantry Top Covers consist of a Right and Left Top Cover, and two fan assemblies. The Top Covers fasten to the front and rear covers, and the fan assembly fastens to the corresponding Top Cover. See Figure 3 for a sample configuration.

Procedure

    Notice Image
    • caution
    • Possible muscle strains and injury.
    • Top Covers with fans are heavy.
    • To prevent muscle strains and injury, always install the Top covers and fan assemblies separately, to reduce the overall weight. If the fan assemblies are currently attached to the Top Covers, remove them before attempting to lift the Top Cover into place.
    Notice Image
    • caution
    • Personal injury or damage to the system.
    • Not turning off the three (3) power switches.
    • Always remove the right side cover first, and turn off the three (3) power switches before removing the top cover.
    Notice Image
    • caution
    • Shock hazard
    • Voltage Present
    • No Service on the TGPU side while energized.
    Notice Image
    • notice
    • Only trained service personnel should service the GE CT Scanner.
  1. Turn OFF the three (3) main power switches (HVDC, 120VAC, and Axial Drive) on the Service Switch Panel (SSP). See Figure 1.

    Figure 1. Service Switch Panel

  2. Remove the Top Cover Fan Assemblies as follows:
    1. Reach beneath the Top Cover and unscrew the captive thumbscrews (Release Screws) that fasten the Fan Assembly to the Top Cover.

      Figure 2. Preparing to Remove the Gantry Fan Assembly

    2. On the Top Cover, disconnect the two power plugs (one to each fan).
    3. Push up on the fans and grab the fan pan from the top to remove the Fan Assembly. See Figure 3.

    Figure 3. Remove Gantry Fan Assembly

  3. With fan assembly removed, lift the end of the Top Cover nearest to the side cover then tilt upwards and slide the cover down about 75 millimeters, to disengage the cover tab from the mounting bracket. See Figure 4.

    Figure 4. Top Cover Tabs

  4. Lift the cover to clear the bracket and Gantry assemblies.
  5. Reinstall fans when needed by reversing this procedure.

Finalization

  1. Verify fan operation by watching fans right after power is restored. All fans should come on initially after gantry power is restored. After the power up sequence, firmware control takes over and may turn some fans off.
  2. Verify all covers, especially side covers are properly secured.
  3. Ensure there is no interference during all tilt range.