Overview#
The Caterpillar 3512C is a 1500 kW standby diesel generator set built around Cat's 51.8-liter V12 engine. Designed for large-scale mission-critical applications, it delivers sustained power for data centers, large hospital campuses, and industrial facilities that cannot tolerate interruption. Its broad voltage range -- including medium-voltage outputs up to 13,800V -- makes it a natural fit for direct bus integration without an intervening step-up transformer.
The 3512C ATAAC (Air-to-Air Aftercooled) uses electronic unit injection with Cat's ADEM 3 governor, providing precise fuel control and excellent transient load acceptance. At the 1500 ekW standby rating, the engine produces 104.6 gal/hr fuel consumption at 100% load, with exhaust gas flow of 11,734 cfm at an exhaust stack temperature of 756 degrees F. The generator set accepts 100% rated load in one step per NFPA 110 and meets ISO 8528-5 transient response requirements.
With NFPA 110 Level 1 compliance and UL 2200 listing availability, the 3512C meets the most demanding life-safety and code requirements. Units are available in open-skid, sound-attenuated, and weather-protective enclosures, and the platform is well-suited to paralleling arrays where multiple units are synchronized for N+1 or 2N redundancy. Optional seismic certification is available per IBC 2000 through 2009 and CBC 2007.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby rating | 1500 ekW / 1875 kVA |
| Prime rating | 1250 ekW (approx.) |
| Rating range | 1230 ekW to 1500 ekW |
| Frequency | 60 Hz |
| Speed | 1800 rpm |
| Voltage | 220V to 13,800V |
| Engine model | Cat 3512C ATAAC |
| Displacement | 51.8 L (3,161 in³) |
| Bore x stroke | 170 mm x 190 mm (6.69 in x 7.48 in) |
| Compression ratio | 14.7:1 |
| Aspiration | Turbocharged-aftercooled (ATAAC) |
| Fuel system | Electronic unit injection |
| Governor | ADEM 3 |
| Emissions | EPA Tier 2 (Stationary Emergency) |
| Fuel consumption @ 100% load | 104.6 gal/hr (395.9 L/hr) |
| Fuel consumption @ 75% load | 82.0 gal/hr (310.5 L/hr) |
| Fuel consumption @ 50% load | 58.0 gal/hr (219.7 L/hr) |
| Fuel consumption @ 25% load | 33.9 gal/hr (128.4 L/hr) |
| Combustion air flow | 4,937.2 cfm at full load |
| Exhaust gas flow | 11,734.1 cfm at full load |
| Exhaust temperature | 756.6 degrees F at full load |
| Motor starting @ 30% voltage dip | 4,350 skVA |
| Alternator frame | 1447 |
| Controller | EMCP 4 (4.2/4.3/4.4 optional) |
Our Service Experience#
Our technicians have maintained and load-tested 3512C units across data center and hospital installations throughout the Bay Area. The turbocharged-aftercooled V12 responds well to step-load events, and we recommend annual wet-stacking prevention load tests given the engine's large displacement and the low average load factors typical of standby duty.
The 51.8-liter displacement means significant lube oil capacity -- oil sampling via Cat's S-O-S fluid analysis program is critical for trending wear metals and catching injector degradation early. Fuel quality management (polishing and biocide treatment) is mandatory given the volume of fuel held in typical sub-base tanks for a 1500 kW unit. Medium-voltage configurations require coordination with a licensed electrical contractor for ATS, switchgear, and protection relay integration; our team is experienced in managing those scopes alongside Cat dealer partners.
Frequently Asked Questions#
What is the standby rating of the Caterpillar 3512C? The Cat 3512C is rated at 1500 ekW (1875 kVA) standby at 60 Hz / 1800 rpm / 480V / 0.8 power factor. The platform supports 1230 ekW to 1500 ekW.
What engine does the 3512C generator use? The 3512C ATAAC -- a 51.8-liter V12 with 170 mm bore, 190 mm stroke, 14.7:1 compression, and electronic unit injection with ADEM 3 governor. EPA Tier 2 for stationary emergency use.
What is the fuel consumption of the Cat 3512C generator? At 1500 ekW standby, the 3512C consumes 104.6 gal/hr at 100% load, 82.0 gal/hr at 75%, 58.0 gal/hr at 50%, and 33.9 gal/hr at 25% load.
What high-voltage output options are available on the 3512C? The 3512C supports 4160V, 12470V, 13200V, and 13800V medium-voltage outputs plus standard 480V and 600V, enabling direct bus integration without a step-up transformer.
What motor starting capability does the 3512C have? At 480V and 30% voltage dip, the 3512C provides 4,350 skVA motor starting capability -- among the highest in Cat's generator lineup.
