Help!! Condensing Unit Trips on High Pressure Daily

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!

non condensables in the system maybe,is it a new system?pump it down at the reciever and check the high side preesure be for lp cut out, i had the same problem not so long ago turned ot it was a faulty hp switch, hope this helps.

Nope it is an older system. We've had some electrical problems recently and now that those are fixed it ran well for a week or two then the hp started tripping. I will be headed to the warehouse soon to check it out. Thanks for the recommendations!!

Hi
check your defrosting cycle ,this could cause this to happen
good luck

hi
check crank case heater range of high pressure on 404 is greater than 22 .defrost terminator must be checked and after defrost fans run directly or based on time or temperature good luck

What are the running suction and discharge pressures of the unit ?
What is the HP switch trip set point ?
Is the condenser fan motor single or 3 phase ?
Is the fan running the correct rotation , correct speed etc ?
What were the electrical problems with the plant?
Have you put extra charge in the unit?