Overview#
The Atlas Copco QAS 250 delivers 200 kW of prime power (250 kVA) from a John Deere 9.0-liter inline-six diesel engine at 1,800 RPM. The 385-gallon integral fuel tank provides over 34 hours of runtime at 75% load, and the unit features an 800A main breaker for the full range of multi-voltage output configurations.
The Leroy Somer LSA 46.2 L6 alternator steps up from the 44.3 series used in smaller QAS models, delivering the higher output capacity needed for 200+ kW applications. At 73 dBA, the QAS 250 maintains competitive noise levels for its power class.
Leroy Somer LSA 46.2 alternator upgrade#
The QAS 250 marks the transition to the Leroy Somer LSA 46.2 series alternator — a larger frame than the LSA 44.3 used in the QAS 125 through QAS 200. The LSA 46.2 L6 delivers the higher current capacity required for 200 kW applications while maintaining the ±0.25% voltage regulation and AREP excitation system consistent across the entire QAS lineup.
This alternator platform is shared with the QAS 330, which uses the LSA 46.2 L9 variant from the same family. The John Deere 6090HFG06 9.0-liter engine is also shared between the 250 and 330, providing significant parts commonality for fleet operators running both models.
Our service experience#
The QAS 250 enters the heavy-duty tier of the Atlas Copco portable lineup, where units are commonly deployed on large construction sites and for utility-scale temporary power. The John Deere 6090 engine is a proven 9.0-liter platform with strong aftermarket support, and the shared platform with the QAS 330 benefits fleet operators who need to stock parts for multiple units.
Atlas Copco's after-sale service continues to be the brand's primary weakness at this size class. The higher value of these units makes the service gap more impactful — downtime on a 200 kW unit is expensive, and waiting weeks for factory parts or service calls is not acceptable. For QAS 250 owners in Northern California, OnPoint provides responsive local service for both engine and genset-level maintenance.
