A320 Center Tank Pumps
Hi all,
Quite often at the gate we get the Low Pressure warning on one or both of the center tank pumps when the fuel quantity in the center tanks are low (anything from 20kgs - 200Kgs). I am aware of the procedure in the FCOM to have the center tank pumps off in this case.
Just an observation, most of the time when we put the pumps back on after the engines are started, the warning goes away and the pumps run normally.
My question is, why does this happen? I would imagine the performance of the pumps are the same before or after engine start as long as they have power supplied to them. So why is it that they are able to run after engine start but detect low pressure at the gate with the same amount of fuel in the tanks?
Also, there are a few occurrences whereby the center tank pumps are in "crosslink green", where auto shut off is required but there are still an unusually high amount of fuel in the tanks. Highest I've seen is 210kg.
Does anyone have frequent experiences with this?