The GPU tripped during start up. If the GPU was reapplied to the aircraft whilst 200vac systems are still running down or the contactors are still closed, then the result would be alot of blown fuses and red faces. If this was the case then I think the ground crew may be a little trigger happy. There are lots and lots of fuses on a Vulcan and to be certain the aircraft is serviceable they ALL need checking.
vickyv, very true. It was always drummed into us that if you lost 200v during pre-start, under
no circumstances must the AEO reinstate 200v until the after landing and shut downs checks have been completed and all 200v rotary loads have been isloated. In fact it was a deliberate part of Ex 1 on the Vulcan OCU - loss of 200v during start.
If the external 200v is re-connected prematurely, there'll then be a
major fuse changing and checking process. In particular, 3-phase systems must be very carefully checked.
Surely the groundcrew and AEO know this?