Atlas Copco · QAS Series

Atlas Copco QAS 95

83 kW standby / 76 kW prime · Diesel · Liquid-cooled

95 kVA (76 kW prime) portable diesel generator. Swedish-engineered QAS series with John Deere engine.

Atlas Copco Atlas Copco QAS 95 generator — specifications and details
Standby power
83 kW / 76 kW prime
Voltage options
120/240V, 208V, 277/480V
Frequency / Phase
60 Hz · 1/3-phase
Engine
John Deere 4045 HFG04 · 4.5L
EPA / Emissions
Tier 4 Final
Alternator
Leroy Somer LSA 44.3 S3
Commercialrental-fleettemporary-power

Overview#

The Atlas Copco QAS 95 JD is a 95 kVA portable diesel generator powered by a John Deere 4045 HFG04 4.5L inline-4 engine. Delivering 76 kW prime / 83 kW standby, it transitions the QAS lineup from Isuzu to John Deere power at this rating. The unit ships in a fully sound-attenuated enclosure, measuring 69 dBA at 7 meters at 75% load — 5-8 dB quieter than most competitors in the 75-100 kW portable class. EPA Tier 4 Final and CARB compliant, it is legal for operation throughout California without restriction.

Technical highlights#

The QAS 95 pairs the proven John Deere 4045 platform with a Leroy Somer LSA 44.3 S3 alternator featuring Class H insulation and voltage regulation within ±0.25%. The turbocharged-aftercooled engine runs at 1800 RPM and delivers strong fuel economy: 4.23 gph at 75% load and 5.36 gph at full load. With a 166-gallon integral diesel tank and a 9.19-gallon DEF tank, the unit offers roughly 39 hours of continuous runtime at typical job-site loads — over a day and a half between refueling stops. Multi-voltage output (120/240V, 208V, 277/480V) in both single- and three-phase configurations provides flexibility across residential, commercial, and light-industrial applications.

Our service experience#

Atlas Copco builds some of the best portable power hardware on the market. The Swedish engineering shows in the QAS series' quiet operation, compact footprint, and fuel efficiency. Where Atlas Copco falls short — and this is a consistent theme across NorCal fleet operators — is after-sale service. Unreturned calls, $311+/hr travel charges, and parts delays are the most common complaints we hear from QAS owners. OnPoint provides a local Northern California service alternative: responsive scheduling, transparent pricing, and technicians who know the John Deere 4045 and Leroy Somer alternators inside and out. If you own or rent QAS units in the Bay Area, we are here to keep them running.

Engineering specifications

Acoustic

Sound @ 7m, 75% load
69 dBA
Enclosure
Sound-attenuated

Fuel system & runtime

Integral fuel tank
166 gal
Fuel use @ full load
5.36 GPH
Fuel use @ 75% load
4.23 GPH
DEF tank
9.19 gal

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Get pricing & lead time on the Atlas Copco QAS 95

Tell us about the application — kW, voltage, application, install timeline — and we'll respond within one business day with budgetary pricing, lead time, and any sizing notes.

Estimate runtime for the Atlas Copco QAS 95

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

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Estimated runtime

40.1 hours(1.7 days)

Fuel consumption ≈ 4.13 GPH at 75% load. Estimate based on industry-typical 1800 RPM standby curves (≈0.07 GPH/kW at full load). Actual consumption varies by engine, ambient temperature, fuel quality, and tuning.

Service intervals

Manufacturer-recommended intervals for the Atlas Copco QAS 95 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.

Oil & filter
Every 500 hours or 12 months
Air filter
Every 500 hours
Fuel filter
Every 500 hours
Major overhaul
20,000 hours

Common failure modes

What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.

ComponentSymptomTypical hoursSeverity
Fuel filterRestricted fuel flow, reduced power, hard starting500+minor
BatteryFailed to start, slow crank, low voltage warning4,380+minor
Coolant hoseWeeping coolant at hose connections, low coolant alarm5,000+minor

Frequently Asked Questions

What is the prime and standby rating of the Atlas Copco QAS 95?
The QAS 95 delivers 76 kW prime power and 83 kW standby power. Prime rating applies to continuous variable-load portable applications; standby is for backup use with an average 70% load factor.
What engine does the Atlas Copco QAS 95 use?
The QAS 95 is powered by a John Deere 4045 HFG04 4.5-liter inline-4 turbocharged-aftercooled diesel engine running at 1,800 RPM. The 4045 HFG04 is shared with the larger QAS 125 and features 500-hour oil change intervals.
What are the service intervals for the QAS 95?
Oil changes are due every 500 hours or 12 months, whichever comes first. Air filter and fuel filter replacement intervals are 500 hours. Major engine overhaul is specified at 20,000 hours. The John Deere 4045 platform also requires DEF monitoring for SCR aftertreatment.
Is the Atlas Copco QAS 95 EPA Tier 4 Final compliant?
Yes. The QAS 95 is EPA Tier 4 Final and CARB compliant, legal for operation throughout California. The John Deere 4045 HFG04 uses DOC and SCR aftertreatment with a 9.19-gallon DEF tank integrated into the unit.
How does the QAS 95 differ from the QAS 125?
Both the QAS 95 and QAS 125 use the same John Deere 4045 HFG04 4.5-liter engine and share similar specs. The QAS 125 extracts 100 kW prime (vs. 76 kW) through a higher-output alternator configuration, and uses the Leroy Somer LSA 44.3 S5 instead of the S3. The 166-gallon fuel tank is the same on both models.
What fuel does the Atlas Copco QAS 95 use?
The QAS 95 runs on diesel with DEF required for SCR aftertreatment. The 166-gallon integral diesel tank delivers approximately 39 hours of runtime at 75% load (4.23 gal/hr). A 9.19-gallon DEF tank is integrated into the unit.
Who services Atlas Copco generators in Northern California?
OnPoint Generators provides local service and maintenance for Atlas Copco QAS units across the Bay Area and Northern California, with technicians experienced on the John Deere 4045 and Leroy Somer alternators. We offer faster response times than the Atlas Copco factory service network.

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