I have been working on the Condensing unit at my warehouse for the Walk in Freezer and the Compressor, Condensing fan, Evap fans, Timer, Contactors etc are fine and look to be running perfectly every day. Yet something happens over night every night that is causing the High pressure to trip and shuts down the unit. I just replaced the Condensing Fan motor yesterday as we had assumed that was the problem when we found it occasionally not running and fully dead yesterday (So we assumed this was the one and only problem relating to the high pressure). SO yeasterday it was replace and we turned it on, every thing worked fine and we hoped that that was our cure, and then today we came in to see a once again tripped high pressure switch. using 404A refrigerant and one big compressor is feeding 2 evaporators.

I read on here that it could be a high charge and is causing the high pressure to trip before the machine can pump down and shut off on low pressure. I wont be able to test that theory today so will be going tomorrow to check that out. Was hoping a few other ideas might pop up on the thread overnight that may help me if the High charge theory doesnt work. Thanks!