A321
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Total 21000
Troubleshooting; Situational Awareness; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Gate; General Flight Cancelled / Delayed
Manuals; Company Policy; Human Factors; MEL
When we arrived at the gate; maintenance had to reapply an MEL that was just cleared. The MEL was being re-issued; it was 27-XX (ELAC) [Elevator Aileron Computer]. The FO (First Officer) and I reviewed the MEL and decided on doing the action items because it dealt with checking the flight controls which meant the hydraulics were pressurized. I realized my error when I was unable to turn on the blue hydraulic pump; on the maintenance panel; to ON after engines start after pushback. The switch would not lock into the ON position. I contacted Maintenance Control via Dispatch and Maintenance Control said to go back to the gate. Maintenance came to the airplane and I explained what happen. The Technician mentioned why the blue hydraulic pump would not turn on; because the system was energized. After he said that; I said you were right and remembered you cannot turn on the switch with engines running. Then we discussed the action items on the MEL. We both; along with FO; were in agreement about how the MEL was written; not in a clear manner. No where does it say to perform the action items with the engines off. The way the action items are written; such as C then D; it only adds to confusion. When you complete action item C; you have completed the task. When you go to D; nowhere does it mention to perform the rest of the action items at the gate or remote area with the engines not running. We performed the action items at the gate and proceeded on our flight.Clarity of the MEL needs to be improved. This MEL is extremely rarely issued; ELACs are extremely reliable. Make mention this must be done at the gate due to the blue hydraulic system must be turned on via the maintenance overhead panel; engines running locks the switch from turning on.
A321 Captain reported confusion on the wording of an MEL action items list after pushback resulting in a return to gate.