The Atlas Copco QAS 625 is the flagship of the QAS portable lineup, delivering 500 kW of prime power from a Volvo TWD1672GE 16.1-liter diesel engine. It is the largest mobile generator Atlas Copco offers in the North American market, mounted on a tri-axle trailer platform at approximately 26,000 lbs.
The AREP alternator excitation system provides 300% overcurrent starting capabilities for high-inrush motor loads. The 707-gallon integral fuel tank with 110% fluid containment supports extended runtime for large construction projects, data center temporary power, and emergency standby applications. SCR-only aftertreatment keeps the Tier 4 Final system simpler than DPF-equipped competitors.
The QAS 625 uses SCR-only (Selective Catalytic Reduction) aftertreatment for Tier 4 Final compliance — no diesel particulate filter (DPF). This is a meaningful advantage over DPF-equipped competitors. DPF systems require periodic regeneration cycles that can interrupt operation and add maintenance complexity. The SCR-only approach on the Volvo TWD1672GE requires DEF (Diesel Exhaust Fluid) but avoids regeneration-related downtime and the associated ash cleaning intervals that DPF systems demand.
For data center and critical temporary power applications, the absence of a DPF reduces the risk of unexpected shutdowns from failed or incomplete regeneration cycles. The 500-hour service intervals and the Volvo engine's established industrial reputation make the QAS 625 a lower-maintenance flagship compared to alternatives with more complex aftertreatment systems.
The QAS 625 is a serious piece of equipment — 26,000 lbs on a tri-axle trailer with a 16.1-liter Volvo engine. Service on units this size requires specialized capabilities, and this is where Atlas Copco's after-sale service weakness becomes most impactful. At 500 kW, every hour of downtime is expensive, and the factory network's pattern of unreturned calls, high travel charges ($311+/hour), and multi-week parts delays is simply not acceptable for critical applications.
The Volvo TWD1672GE engine does benefit from Volvo's industrial engine dealer network for engine-specific service, which provides an alternative channel for major engine work. However, Atlas Copco-specific components — enclosures, control systems, AREP excitation components — must come through Atlas Copco's own supply chain. For QAS 625 owners in Northern California, OnPoint provides local service support with the capability to handle large mobile units and experience across the full QAS lineup from 20 kW to 500 kW.
Engineering specifications
Physical
Length
260 in
Width
102 in
Height
118 in
Wet weight
26,000 lb
Fuel system & runtime
Integral fuel tank
707 gal
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Get pricing & lead time on the Atlas Copco QAS 625
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.
Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.
Estimate runtime on this tank
Estimated runtime
23.8 hours(1.0 days)
Fuel consumption ≈ 29.70 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 625 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.
Component
Symptom
Typical hours
Severity
Fuel filter
Restricted fuel flow, hard starting, power loss
500+
minor
Starting battery
Failed start or slow cranking after extended storage
4,380+
minor
Coolant hoses
Weeping at clamp joints, low coolant warning
5,000+
minor
Frequently Asked Questions
What is the prime and standby rating of the Atlas Copco QAS 625?
The QAS 625 delivers 500 kW prime power and 550 kW standby power. It is the flagship of the QAS portable lineup and the largest single-engine mobile generator Atlas Copco offers in the North American market.
What engine does the Atlas Copco QAS 625 use?
The QAS 625 is powered by a Volvo TWD1672GE 16.1-liter inline-6 turbocharged-aftercooled diesel engine running at 1,800 RPM. The TWD1672GE is Volvo's industrial power generation platform with an established dealer network for engine-side service support.
What are the service intervals for the QAS 625?
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 QAS 625 uses SCR-only aftertreatment — no DPF to regenerate or clean — simplifying aftertreatment maintenance.
Is the Atlas Copco QAS 625 EPA Tier 4 Final compliant?
Yes. The QAS 625 is EPA Tier 4 Final and CARB compliant, legal for operation throughout California. It uses SCR-only aftertreatment (no diesel particulate filter), which avoids DPF regeneration cycles and associated maintenance complications.
How does the QAS 625 compare to the QAS 700?
The QAS 700 uses the Volvo TWD1683GE 16.1-liter engine delivering 560 kW prime vs. the QAS 625's 500 kW. The QAS 700 is rated at 76 dBA at 7 meters and adds a 43.4-gallon DEF tank. Both share a 707-gallon fuel tank. The QAS 700 also outputs only three-phase 277/480V vs. the QAS 625's multi-voltage options.
What fuel does the Atlas Copco QAS 625 use?
The QAS 625 runs on diesel with DEF required for SCR aftertreatment. The 707-gallon integral fuel tank provides approximately 20-24 hours of runtime at 75% load. The 110% fluid containment base eliminates the need for separate secondary containment on most sites.
Who services Atlas Copco generators in Northern California?
OnPoint Generators provides local service support for Atlas Copco QAS units including the Volvo-powered QAS 625 across Northern California. At 500 kW, downtime is expensive — we offer faster scheduling than the Atlas Copco factory service network and experience across the full QAS lineup from 20 kW to 500 kW.
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