M1 Cover Fault during closing

This is triggered when the Upper Enclosure trapped key is removed.

Removing the trapped key removed disables Aperture Cover drives.

The unintended stop may cause an Aperture Cover drive fault.

When Aperture Cover drives are disabled GIC closes the M1 cover and the Aperture Cover.

Since the Aperture Cover is disabled and possibly faulted, it will fail to close. This will generate a Aperture Cover close Timeout fault. This fault can be cleared after the command to close the Aperture Cover has been removed.

The only way to clear the Aperture Cover close command is to close the M1 Cover.

Recovery Procedure

1. Return all trapped keys to their original position.

2. Reset Aperture Cover faults in EMCS. CAUTION: Aperture Cover will move when you do this.

3. Wait for Aperture Cover to close.

4. Reset GIS Fault (using Engineering screen of GIS HMI).

5. Reset GIS.

6. Re-open Aperture Cover.

7. Re-open M1 Cover.

Following is for information only, this procedure is not implemented:

With a JHA, the workaround procedure would be:

1. Close M1 Cover (optionally Aperture Cover could be closed).

2. Remove trapped keys to gain access (in this case A->B->C.

3. Personnel safely access catwalk.

4. Close gate. Return trapped keys C->B->A.

5. Reset GIS (if needed).

6. Resume tracking the Sun. (Enclosure: reset, then re-enable drives, begin tracking)

7. Open the M1 Cover (or Aperture Cover).

8. Perform tasks as needed. (N.B. currently, don’t touch TEOA platform gate, it could inadvertently trigger an interlock).

9. Close M1 Cover (optionally Aperture Cover could be closed).

10. Remove trapped keys to gain access (in this case A->B->C.

11. Personnel safely leave catwalk.

12. Close gate. Return trapped keys C->B->A.

13. Reset GIS (if needed).

14. Resume tracking the Sun. (Enclosure: reset, then re-enable drives, begin tracking)

15. Open the M1 Cover (or Aperture Cover).