I have a Atlas Copco GA 90. element outlet temperature is coming on. The temperature reading at the display will be at around 82 degrees and then spike and jump to 210 degrees and then the element outlet temperature comes on.
Can you tell if it’s actually going up that much? Over what period of time?
If it’s truly a jump (like a couple of seconds), then I’d suspect the sensor itself or wiring from it to the controller.
GA 90 advice
if the unit is tripping on high temp immediately after starting the problem is your oil stop valve sticking (very common on GA90, 15 minutes to replace)
If it takes a few minutes to overheat it is caused by a faulty thermostat valve.
I make the assumption that op has checked the obvious: low oil level, plugged oil cooler?