Overview#
The Caterpillar G3412 is a 512 kW standby natural gas generator set built on the G3412C -- a 27-liter, 12-cylinder V12 spark-ignited engine that brings large-output natural gas capability to hospitals, industrial campuses, and commercial facilities where diesel fuel storage is impractical or restricted. Operating on pipeline natural gas eliminates the need for on-site fuel management, extended diesel storage permitting, and regular fuel polishing, all of which reduce long-term operating costs.
The G3412C engine features an electronic fuel control valve governed by Cat's ADEM A4 electronic governor, providing precise air-fuel ratio control across the full load range. At 11.4:1 compression ratio and turbocharged aspiration, the G3412C is designed for maximum performance on low-pressure gaseous fuel supply -- a key design characteristic for hospital and campus installations where gas service pressure may be limited by utility infrastructure.
The G3412 is factory certified to U.S. EPA 40 CFR Part 60 Subpart JJJJ for stationary emergency use only, and accepts 100% rated load in one step per NFPA 110 Type 10 starting and loading requirements. Standard controller is the EMCP 4.3 or 4.4, with load share module and remote monitoring software available as options.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby rating | 512 ekW / 640 kVA |
| Frequency | 60 Hz |
| Speed | 1800 rpm |
| Power factor | 0.8 |
| Voltage options | 208V, 220V, 440V, 480V, 600V |
| Fuel | Natural gas |
| Engine model | Cat G3412C |
| Displacement | 27 L (1,648 in³) |
| Bore x stroke | 137 mm x 152 mm (5.4 in x 6.0 in) |
| Compression ratio | 11.4:1 |
| Aspiration | Turbocharged |
| Fuel system | Electronic fuel control valve |
| Governor | ADEM A4 |
| Emissions | EPA 40 CFR 60 Subpart JJJJ (Stationary Emergency) |
| Length (narrow base) | 149.5 in (3,796 mm) |
| Width (narrow base) | 73 in (1,854 mm) |
| Height | 85.2 in (2,163 mm) |
| Dry weight (narrow base) | 14,330 lb (6,500 kg) |
| Oil change interval | 250 hours |
| Spark plug interval | 1,500 hours |
| Major overhaul | 15,000 hours |
| Controller | EMCP 4.3 / EMCP 4.4 |
| Warranty (standby) | 24 months standard |
Our Service Experience#
We have experience maintaining G3412 units in large hospital and campus environments where natural gas is the primary standby fuel. The V12 gaseous engine demands disciplined spark ignition system maintenance -- 12 spark plugs, ignition modules, and timing all require tracking in a structured PM program.
We use dedicated Cat gaseous engine service procedures for G3412 units, which differ significantly from diesel PM in several ways: oil change intervals at 250 hours (half of diesel), spark plug replacement at 1,500 hours as a firm schedule rather than condition-based, and charge air cooler inspection at 10,000 hours. We advise clients with G3412 units to maintain a full ignition kit on-site -- 12 spark plugs plus ignition modules -- to minimize downtime when scheduled replacement falls due. Annual load bank testing confirms power output, transient response, and adequacy of the utility gas supply pressure under full-load conditions.
Frequently Asked Questions#
What is the output of the Caterpillar G3412? The Cat G3412 is rated at 512 ekW (640 kVA) standby at 60 Hz / 1800 rpm / 0.8 power factor, EPA-certified for stationary emergency use.
What engine does the G3412 use? The G3412C -- a 27-liter V12 turbocharged spark-ignited natural gas engine with 137 mm bore, 152 mm stroke, 11.4:1 compression, and ADEM A4 electronic governor with electronic fuel control valve.
What are the physical dimensions of the G3412 generator set? Narrow base: 149.5 in long x 73 in wide x 85.2 in high. Dry weight 14,330 lb (6,500 kg). Wide base adds approximately 16 inches to width.
Does the G3412 support paralleling applications? Yes. The EMCP 4.3/4.4 controller supports load sharing and paralleling control modules for multi-unit synchronized arrays.
What compliance certifications does the G3412 carry? EPA 40 CFR Part 60 Subpart JJJJ factory certification for stationary emergency use. Optional UL 2200 and CSA certification. Conforms to NFPA 110 Type 10 and ISO 8528-5 G2 load acceptance.
