Our 55 kW screw compressor loads every four minutes or so overnight with the plant empty. Boss says leaks and wants me to find them. The load solenoid and run contactor already go through a CompactLogix in the compressor room, that's how the run hours get to the HMI.

I've walked the plant with a soap bottle twice and fixed a few fittings, overnight loading barely changed.

Someone suggested a bigger receiver so it loads less often. Is there a way to use the PLC to tell me where the air's going, or is it soap bottle until I find them all?