Why won't my Atlas Copco start after fan breaker Q15 tripped?
Short answer: Fan motor circuit tripped. If your Atlas Copco GA 30+-90 / GA 37+ (Elektronikon Touch) is showing Circuit breaker (Q15) or fan motor overload (F15) open, the controller has logged a specific, documented condition. This page covers what it means, what causes it, what you can safely fix yourself, and when — and why — it takes a technician.
What exactly is the machine telling you?
The fan motor's circuit breaker Q15 or overload F15 has opened, stopping the unit or preventing start. Without the fan the machine would overheat, so the controller keeps it down until the fault is cleared.
Which machines show this?
Atlas Copco's current-generation GA 30+ through GA 90 oil-injected rotary screws — the '+' models such as the GA 37+ — carrying the Elektronikon Touch controller with its color touchscreen. These are the newest machines in the GA line, and their instruction books lean on documented cause lists (oil level, cooling air, relay designations like F21, Q15, F15, K25) rather than bare code numbers, so faults often read as plain-language conditions. Practical tip: the manual warns that pressing the emergency stop does not make the compressor voltage-free — any electrical-cabinet check on these machines starts with switching off and locking out the supply, full stop.
What causes it?
- Fan blocked by debris or not spinning freely
- Dirt-loaded cooler faces increasing the fan's load
- Breaker Q15 or overload F15 opened and needs cool-down before reset
- Fan motor or protection-setting fault if it trips again
Can you fix it yourself?
Sometimes — clearing a blocked fan and cleaning the coolers, then resetting after cool-down, fixes the simple cases.
Step by step — what to try, in order:
- Switch off and lock out the voltage
- Check the fan for blockage or debris and confirm it spins freely
- Check cooler faces for dirt loading that increases fan load
- Have the breaker/overload reset after cool-down and monitor the restart
When do you need a technician — and why?
The reset happens inside the electrical cabinet under lockout, and a repeat trip needs an electrician to test the fan motor and verify the breaker/overload settings.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service industrial air compressors — real businesses with verified contact information, none of whom paid to be listed.
Related questions
What does Circuit breaker (Q15) or fan motor overload (F15) open mean on an Atlas Copco GA 30+-90 / GA 37+ (Elektronikon Touch)?
Fan motor circuit tripped. The fan motor's circuit breaker Q15 or overload F15 has opened, stopping the unit or preventing start. Without the fan the machine would overheat, so the controller keeps it down until the fault is cleared.
Can I fix Circuit breaker (Q15) or fan motor overload (F15) open on an Atlas Copco GA 30+-90 / GA 37+ (Elektronikon Touch) myself?
Sometimes — clearing a blocked fan and cleaning the coolers, then resetting after cool-down, fixes the simple cases.
When does Circuit breaker (Q15) or fan motor overload (F15) open on an Atlas Copco GA 30+-90 / GA 37+ (Elektronikon Touch) need a technician?
The reset happens inside the electrical cabinet under lockout, and a repeat trip needs an electrician to test the fan motor and verify the breaker/overload settings. If Q15/F15 trips again, the fan motor or its protection setting needs professional diagnosis.
Verified against service documentation: Atlas Copco GA 30+-90 / GA 37+ (Elektronikon Touch) documentation for Circuit breaker (Q15) or fan motor overload (F15) open (manualslib.com)