Compressor GA45 with electronic on shut down

that's a big unit. Reach out to Atlas Copco technical department direct.

http://originair.atlascopco.com/atlascopconew/contact.aspx

http://originair.atlascopco.com/atlascopconew/industrial/compressors/atlas-copco-ga-45-ff/75ef5d89-fc23-4eca-8c0c-d5a823922470.html

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Find the wires that go into the clutch on the front of the compressor and unplug it.

Dirty coil wash outside unit with water and change indoor unit filter

A couple of possibilities: Coolant level has declined too far; compressor has failed, and finally, the defrost timer has failed. During the defrost cycle, the compressor is intentionally shut down and if the defrost timer has failed during the defrost cycle, the compressor will not be re-enabled.
You didn't include the model number so the following may not apply: The defrost timer is often located behind the lower grill of the unit. Remove the grill (often held by plastic tabs) and look for a small black box with a hole or a short protruding shaft. These often have a screwdriver slot to allow manual rotation in the event of a timer motor failure. If you find this, insert a flat-bladed screwdriver and rotate the shaft ~ 1/4 turn and wait to see if the compressor then starts up. If not, turn the shaft a bit further and wait again.
If the compressor does not start, either the relay that supplies AC to the compressor has failed or the compressor itself.

this could be a stuck compressor or a low voltage condition shut it down as the compressor is only getting hotter. wait about 1 hour and tryagain hope this helps let me know Jon

This is letting you know the motor rotation is incorrect. If this is a new unit or has just been installed or other rewiring work done in your plant etc. you need to get your electrician to roll 2 of the 3 incoming power leads. If this compressor has been in service and operating you have a vacuum switch or transducer possibly bad. you also need to check the transducer line or vacuum switch line ( both are normally 1/4 inch plastic tubing) for tightness and leaks. For example the line has rubbed a hole in it. When you try to start the unit the transducer does not see the required vacuum. The controller interrupts this low or no vacuum as the rotation is incorrect and thus gives a check motor rotation alarm and shuts down.

When the Pressure switch shuts off, the little air valve in the pressure switch vents the copper line from the compressor, to blead the pressure from the compressor so it's easier to start the next time. If it continues to leak, the check valve between compressor and tank must not be holding.

The outside unit has a fan capacitor and it must be faulty!!! thae capacitor tells the fan to rotate and if the fan does not work then the compressor will shut down due to a high head pressure and temperture!! change the capacitor located in the electrical section of the outside unit and it should work fine...

When it shuts down, press DISPLAY SELECT button once and use the up down arrows to see the code just before shutdown.

HIGH AIREND TEMP

HIGH AIR PRESSURE

LOW SUMP PRESSURE

PRESSURE OR TEMP SENSOR FAIL

CHECK MOTOR ROTATION

MOTOR OVERLOAD

FAN MOTOR OVERLOAD

STARTER FAULT

I am assuming this has a Intellisys controller.

Blinking or chattering of the compressor clutch usually indicates low "freon" charge.