Regarding Original Question
The start relay energizes when the engine start valve opens.
The energized relay contacts send a signal to close the bleed
air regulator solenoid valve.
i.e. Bleed is closed automatically during start, restores to selected position after start.
The open and close coils on the bleed air regulator solenoid
valve are constant duty coils. The solenoid valve also has a
mechanical latch. When there is a loss of electric power, the
solenoid valve will stay in the last electrically commanded
position.
The Engine Hyd Pumps are enegized OFF. The bleed system is not the same it's a twin coil latched type.