• Topic ID: id_15460472
  • Version: 2.0
  • Date: Nov 8, 2018 1:38:33 AM

Stationary 48 Volt Power Supply Replacement

Prerequisites

Overview

This procedure defines the steps to replace the 48V Power supply on the stationary side of the gantry.

Procedure

    • warning
    • Potential for shock.
    • Voltage may be present. Potential for injury if covers removed and power is left ON.
    • Always remove the right side cover first. Follow appropriate LOTO procedures.
  1. Remove gantry right side cover.
    note:

    Replacement should be done from the front or back of the gantry.

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

    2. Notice Image
    • notice
    • Always turn OFF the HVDC before the 120VAC. Turning OFF 120VAC power before HVDC power can result in equipment damage.
  2. Turn OFF the three (3) main power switches (HVDC, 120VAC, and Axial Drive) on the Service Switch Panel (SSP).
  3. Perform all required LOTO procedures before beginning this procedure.
  4. Remove the gantry left side cover. If more access is needed due to gantry position in room, remove gantry top and rear covers.
  5. The stationary 48Vdc supply is located on the gantry right side above the TGPU. See Figure 1.

    Figure 1. 48V Power Supply

    note:

    There are different versions of the power supply, all attach to the same mounting points.

  6. There are four (4) hex head screws holding the supply on the mounting plate that will need to be removed.
  7. Rotate the power supply 90 degrees to gain access to the rear power safety shield and remove.
  8. Remove the AC and DC power connections.
  9. Reconnect all power leads to new supply power and mount the supply with the 4 screws.
  10. Install safety shield and all removed hardware and securely tighten

Finalization

  1. Remove the Lockout/Tagout, and power up the console.
  2. Install all removed gantry covers. Be sure to reconnect all top cover fan connections. Check that no cables are left in the rotating path. Return dollies to storage areas.
  3. Turn on the 120 VAC, HVDC and Axial Drive service switches from the service switch panel.
  4. Make sure the top cover fans power on during gantry power up.
  5. Make sure the fan for the gantry heater/blower assembly is operating.
  6. Verify no gantry fan or heater/blower related error messages are shown in the system error log after gantry power up.