Unit builds to 25-30 psi then shuts off. You must

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

..

This usually occurs when the motors internal thermal / amp breaker opens due to overload or weak breaker. Use an amp gauge to test for too much amp draw. If amp draw is normal, then problem could be the in-tank check valve leaking pressure back to the pump overloading the system, or weak capacitor or weak breaker. Bypass the breaker temporarily if the amp draw is normal to test system. Good luck

THE OUTSIDE FAN MOTOR MIGHT NOT BE WORKING CAUSING THE COMPRESSOR TO GET HOT AND TRIP THE INTERNAL OVERLOAD IN THE COMPRESSOR - IF THE UNIT IS LOW IN FREON SAME RESULTS - WHEN UNIT IS FIRST TURNED ON DOES IT BLOW COLD AIR OR DOES THE AIR NOR FEEL COOL - JUST COOL AIR COULD BE LOW FREON - COLD THEN WARMS UP IS FAN PROBLEM

check fuel pressure, should be 40 psi.
try 2 things

spray starting fluid in air intake to see if it will stay running. It's fue then.

Try turning key to on nd wait 5 seconds for system to build pressure and pump to shut off. Turn key off, wait for relay clcik noise or 10 seconds. then turn key to ON again and wait 5 seconds to build pressure again. Then start engine. If it starts better, you have a bad check valve in the fuel pump or a bad pressure regulator on the fuel rail (unlikely).

report back

It sounds like you need to replace the run capacitor , if yours is weak or defective the motor will overheat. Check "Drillspot" for a replacement. Another major cause of overheating is due to a dirty air filter , you should check it first.

Don F

You have a bad check valve

Most likely it is the unloader valve. This is inline with the air filltube from compressor to tank. Somestimes the unloader valve is screwed into the tank and air tube is attached to it. This device takes the pressure out of the tube so the compressor can start without the back pressure from in the tank. Other possibility, the start capacitors of the motor. The capacitors must give a kickstart upon startup or the motor will just hum for a couple seconds and overload the breaker. A tempoary solution is to turn off the power to compressor when it reaches 120psi, then allow the pressure to drop to 40 or less, then turn power on and mostlikey compressor will start with a load of 40psi or less. It is a nuisance but it works until you replace the bad part. Goodluck,Macgivor

your max pressure switch is faulty, and shutting off the power early. replace switch, check owners manual for location(should be near power wires)

I had the same problem and the solution was to manually press the thermal overload button. The button is located under the tool box next the motor head. I do not believe I tripped the thermal overload during use, but I suppose anything is possible. I’ve been using the compressor in sub 40 deg F. temperatures. I found the following in the Owner’s Manual, but had to look at the part manual to locate the switch.
MOTOR THERMAL OVERLOAD
PROTECTOR: The electric motor
has a manual thermal overload
protector. If the motor overheats
for any reason, the thermal
overload protector will shut off
the motor. Turn pressure switch
to the “off” position and wait for
unit to cool before pushing the
reset button and restarting the
compressor.

Good Luck!

This sounds like you have a high voltage problem. When your unit turns on the high voltage builds up to the operating voltage. Apparently something is overloading the circuit which causes the set to shut down for safety reasons. This locks out the controls and you can't restart it until the power is removed which resets the micro. The unit is going to need professional help if you are not an electronics technician, and I'm guessing you aren't. This should not be a hard fix and the cost should be reasonable. Find a good repair shop and get an estimate or get it repaired. Good luck.