Overview#
The Cat G3520H is Caterpillar's largest gas generator set platform, delivering up to 2,500 ekW continuous power from a 97.5-liter V-20 natural gas engine. Designed for cogeneration, distributed generation, and baseload industrial applications, the G3520H features electronic fuel control, ADEM A4 governor with integrated intelligence module, and support for up to 25% hydrogen blending by volume.
Available in two compression ratio configurations — 11.1:1 (humidity/fuel tolerant) and 12.1:1 (high efficiency) — the G3520H adapts to varying fuel quality and site conditions. Voltage options range from 380V through 11,000V medium voltage.
Key specifications#
- Continuous power: 2,485-2,500 ekW (3,106-3,125 kVA) at 0.8 power factor
- Engine: Cat G3520H, V-20, 97.5L displacement
- Bore x stroke: 170 mm x 215 mm (6.7 in x 8.5 in)
- Compression ratios: 11.1:1 (humidity/fuel tolerant) or 12.1:1 (high efficiency)
- Fuel: Natural gas with up to 25% hydrogen blend capability
- Fuel system: Electronic fuel control valve with ADEM A4 w/IM governor
- Speed: 1,500 RPM (50 Hz)
- Dry weight: 54,675 lb (24,800 kg)
Package configurations#
The G3520H is available in four configurations:
| Configuration | Compression Ratio | Power (ekW) | NOx Options |
|---|---|---|---|
| Humidity/Fuel Tolerant (w/pumps) | 11.1:1 | 2,485 | 250 or 500 mg/Nm3 |
| Humidity/Fuel Tolerant (w/o pumps) | 11.1:1 | 2,500 | 250 or 500 mg/Nm3 |
| High Efficiency (w/pumps) | 12.1:1 | 2,485 | 250 or 500 mg/Nm3 |
| High Efficiency (w/o pumps) | 12.1:1 | 2,500 | 250 or 500 mg/Nm3 |
Hydrogen capability#
The G3520H supports up to 25% hydrogen blending by volume, available as a factory option or retrofit kit. This positions the platform for the energy transition as facilities explore low-carbon fuel strategies. Hydrogen-capable units may experience rating adjustments based on site conditions and fuel blend composition.
Enclosure options#
- Industrial Grade: 15 dB attenuation
- Residential Grade: 18 dB attenuation
- Critical Grade: 25 dB attenuation
Our service experience#
The G3520H is a large-format gas engine requiring specialized expertise. With 20 cylinders and nearly 100 liters of displacement, comprehensive preventive maintenance programs are essential. Key service items include spark plug condition, valve lash adjustment, ignition timing, and aftercooler integrity. The electronic fuel control system must be properly calibrated for the site's specific gas composition and methane number. Extended-life oil tanks and positive crankcase ventilation systems reduce maintenance frequency for continuous-duty installations.
FAQ#
What is the continuous power output of the Cat G3520H?#
The Cat G3520H delivers 2,485 to 2,500 ekW continuous power at 1,500 rpm (50 Hz) depending on configuration. Two compression ratio variants are available: 11.1:1 (humidity/fuel tolerant) and 12.1:1 (high efficiency), each available with or without pumps.
What engine does the Cat G3520H generator use?#
The G3520H -- a 97.5-liter V-20, four-stroke turbocharged natural gas engine with a 170 mm bore, 215 mm stroke, available in 11.1:1 or 12.1:1 compression ratios. Governed by the ADEM A4 w/IM electronic control system with integrated air-fuel ratio management.
What are the service intervals for the Cat G3520H?#
The G3520H is designed for continuous duty. Service intervals include oil change every 2,000 hours, air filter at 4,000 hours, and major overhaul at 64,000 hours. Spark plugs, ignition components, and aftercooler condition are the primary wear items on this gas platform.
Can the Cat G3520H run on hydrogen-blended natural gas?#
Yes. The G3520H supports up to 25% hydrogen blending by volume with natural gas, available as a factory option or retrofit kit. This positions the platform for low-carbon fuel strategies as green hydrogen supply becomes available. Power ratings may vary based on hydrogen blend ratio and site conditions.
Who services Cat G3520H generators in Northern California?#
OnPoint Generators provides installation, maintenance, load bank testing, and emergency service for Caterpillar generators throughout Northern California and the Central Valley. As an authorized dealer network partner, we stock common Cat parts and have factory-trained technicians. Call us for service within a 150-mile radius of Sacramento.
What fuel does the Cat G3520H use?#
The G3520H runs on pipeline-quality natural gas with up to 25% hydrogen blending capability. The two compression ratio configurations (11.1:1 and 12.1:1) accommodate different fuel quality and methane number requirements.
What voltage options are available on the Cat G3520H?#
The G3520H supports 380V, 400V, 415V at low voltage and 3,300V through 11,000V at medium/high voltage (50 Hz), providing a wide range of distribution architecture options for campus and industrial installations.
How does the Cat G3520H compare to the G3520E?#
The G3520H delivers up to 2,500 ekW versus the G3520E's 2,022 ekW, uses ADEM A4 w/IM controls versus the G3520E's ADEM3, and adds 25% hydrogen blending capability. Both share the V-20 engine block architecture with 97.5L displacement.
