Compressor unload time running good 1500RPM but load given time RPM gone low (belot700) & compressor trip emedietly.
Does it sound like the engine is struggeling to keep up, before it shuts down?
If I am correct this compressor as a Caterpillar engine. The RPM is set electronically.
So most probably, the engine doesn’t have the power needed to keep the compressor running.
OR, the compressor is ‘asking’ for too much power.
Is the pressure setting correct? Not too high? Try it with a lower pressure setting to see what happens.
In some cases, with a very very dirty oil separator, this could be the cause (pressure inside the compressor rises too high and compressor asks too much power).
But most probably (most of the time), the problem is with the engine.
Try to replace the fuel filters. Replace or clean the air filters.
If the problem is still there.. most probably you will need a Caterpillar technician to check the engine.. you can’t just change the fuel injectors for example, everything is centrally controlled by the Caterpillar controller. There’s only so much you can do without the special caterpillar software and tools.
Hope this was helpful. Let me know if you need any more helps. Also, I’d love to hear if you’re able to solve the problem.