DOOR WARNING
Firstly,the doors are not electrically locked.All a319/20/21 pax service doors have a warning system consisting of a red light and warning horn should the crew attempt to open doors whilst the aircraft is still pressurized.The captain would have realized that this was a false warning by referencing his pressurization screen and seeing that the outflow valves were fully open.down powering the aircraft would stop the warnings.the crew are told not to open doors with warnings in place,even if it is proved to them its a false warning so removing the power stops the warnings and allows the crew to open door without them compromising their training