Originally Posted by KristianNorway
Let's say you set 370 on the FLT ALT-selector and climb to FL400. Why may you get an overpressure situation?
Because the CPC calculates a target cabin pressure based on what is set on the cabin pressure control panel. This will then result in the expected differential pressure if you are at the same flight level as selected on the control panel. Go above the selected FL and the differential pressure will increase. Basic stuff really.