A320 Series CTR "pumps"
 

Gents and ladies,

The more recent MSNs have transfer valves in the centre tank that use motive flow to get fuel out of the centre tank. The energy for the process comes from the wing tank pumps. I'd expect the on-side centre tank "pump" to be inoperative should both wing pumps fail, however, there's no mention of this in the MEL. I take that to assume the ctr tank fuel would either be unusable, or only accessible via the crossfeed. Am I over or under thinking this? If it's unusable, I'd think the MEL would cover this eventuality, but it doesn't.

Thanks

The MEL does cover this scenario. It is a No Go item.

Agreed. Wing tank pump. Number installed, 4. Number required, 3. So you can’t go with 2 u/s.

Ah. I overlooked that. You guys are correct. Thanks. This spurred me to look up this ECAM.

FUEL L (R) TK PUMP 1 + 2 LO PR (CENTER TANK NOT EMPTY)

It concludes by directing you to the gravity feed checklist, and the status page showing CTR TK FEED: MAN ONLY

I suppose the centre tank fuel wouldn't technically be trapped. You'd just have to send it the long way around.

I believe you are mixing up different MSNs here. If You are talking about jet pumps equipped MSNs there is no distinction between center tank empty or not as the fuel will still be fed to the side with the pumps operating (there needs to be a suction in the jet pump created by the wing pumps as you have written above).