30 HX High Discharge Temp

I am working on a 30HX that keeps going off on high discharge temp. I was able to narrow it down that it is only tripping when the first load solenoid is being energized. It will run fine unloaded but as soon as it loads it trips off. It also has another compressor on the same circuit and it will run just fine with no problems. I can even get them both to run A1 is unloaded and A2 is loaded no probmles, but as soon as it loads up it trips. I dont think it is low refrigerant because the other compressor can run just fine by itself or even both together, if I run A1 by itself it trips. Any ideas? I would think it has to do something with my capacity control.

welcome to Re.Cause of high discharge temperature of screw compressors.
1. High suction temperature.
2. High discharge pressure.
3. High oil temperature and insufficient oil supply to rotor housing.
4. Lack of liquid injection.
5. Increase in the rotor end clearance.
Analyze your operation parameters and compare to the above.

Did you checked with control thermometer that it actualy trips at correct trip temperature?