747-400 (GE) #1 and #4 ADP's will run continuously in AUTO if the FUEL CUT-OFF switch is at CUT-OFF. Otherwise they will run in AUTO if the EDP pressure drops below 1400 PSI for longer than 0.3 secs (pump will then run for 14 secs to prevent cycling of ADP). If the TE FLAPS are away from ZERO position in the AIR the ADP will also run continuously . TE FLAP activation is like DENZIL said from the FCU's.
#2 and #3 ACMP's will also run if system pressure drops to 1400 PSI or the FUEL CUT-OFF switch is at OFF.
All logic is processed by the HYDIM.