Sometimes EEV controls condenser fans.
This could do it.
The digital scroll is actually a cool
device. It allows a greater range of capacity control than traditional unloaders on a recip.
It is designed to load / unload frequently to deliver a specific output. 40% load time = 40% capacity. Better load matching.
Most units are sized for peak load and run there a small percentage of time. So you have an oversized 10 ton scroll cycling on and off. Over and over. Hard on the compressor for sure. This compressor can stay running and stay healthy.
Oil management with these is a whole different topic.
If you haven't seen just what the MC coils look like, you really need to take a look. What you have is pretty much a 1"x 1/8" flat piece of aluminum with say 10 to 15 capillary tubes running the length of the aluminum bar. They don't hold very much refrigerant in them. It is very easy to trip the HP switch with even a slight overcharge.
Ok i'll keep that in mine if i have to go back!! I figured i couldn't go wrong by following the manual's charging instructions!
Carrene #2 you made the most sense. I figured a plugged drier but couldn't figure high pressure trips. I also assumed a pressure switch not a DDC controller. I am not familiar with the equpment being described. Was this an actual pressure switch shutting the comp down or a program in the controller? What brand?