Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance
General None Reported / Taken
Aircraft; MEL
Upon showing to the airport and checking the logbook as I normally do; I found that the MEL 28-15-XX and 28-15-XX that were applied to Aircraft X the previous two days had been changed for misapplication of the MEL. The correct MEL should have been 28-15-XX and 28-15-XX which considers the outer tank fuel unusable for flight planning calculations. When the first two MELs were applied the situation we had (transfer valves opening on ground) seemed to be the correct MEL. After subsequent flights on [the next day] another crew saw the transfer valves did not open and suspected the wrong MEL had been applied. This plane has had multiple issues with the fuel system and everything Maintenance does to fix the problem doesn't seem to fix the issue. I am filing this report because possibly flew the airplane with the incorrect MEL applied. When I flew the airplane the MEL seemed to be correct in that the transfer valves were open and that the fuel from the outer tanks drained to the inner tanks before the inner tank reached its low level sensor to command them to open. If the future if I am ever uncertain about an MEL; I will talk to the local mechanic and Maintenance Control to make sure we are all on the same page and that we get the right MEL applied.
A320 First Officer reported MEL may or may not have been applied correctly as associated with the fuel system.