Caterpillar · Cat C-Series (Diesel)

Cat C15

500 kW standby / 455 kW prime · Diesel · Liquid-cooled

500 kW diesel standby generator with Cat C15 ACERT engine. Large commercial standby for hospitals, high-rises, and municipal infrastructure.

Caterpillar Cat C15 generator — specifications and details
Standby power
500 kW / 455 kW prime
Voltage options
208V, 240V, 480V, 600V
Frequency / Phase
60 Hz · 3-phase
Engine
Caterpillar C15 ACERT · 15.2L
EPA / Emissions
Tier 2

Overview#

The Cat C15 is a 500-kilowatt diesel standby generator built on Caterpillar's proven 15.2-liter ACERT inline-6 platform. It occupies the large-commercial bracket: big enough for hospitals and high-rises, compact enough for standard mechanical rooms. The C15 platform has decades of field history across trucking, marine, and industrial applications — bringing unmatched institutional knowledge to the standby power market.

The Cat ecosystem#

Choosing Cat means buying into an ecosystem:

This ecosystem provides comprehensive support but creates vendor lock-in. Unlike DSE/ComAp-based generators (Kohler, Gillette, etc.), you're committed to Cat's service channel.

Our service experience#

The C15 ACERT is a proven platform. Cat's dealer network in Northern California (Peterson Cat, Holt Cat) provides excellent emergency parts availability. We service C15 units at hospitals and large commercial accounts. The MEUI fuel injection system is Cat-specific — requires Cat Electronic Technician (Cat ET) software for diagnostics. This is the main lock-in consideration: you need either Cat-trained technicians or a Cat dealer relationship for anything beyond basic PM.

Engineering specifications

Physical

Length
135 in
Width
60 in
Height
84 in
Wet weight
9,850 lb

Acoustic

Sound @ 7m, full load
75 dBA
Enclosure
Sound-attenuated

Fuel system & runtime

Integral fuel tank
400 gal
Fuel use @ full load
27.4 GPH
Fuel use @ 75% load
20.6 GPH

Units For Sale

View all (1)
Used

613 hrs

$87,500

Houston, TX

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Lock the enclosure, fuel system, transfer switch, and add-ons — we'll confirm pricing, availability, and lead time within one business day. Prefer a free-form quote? That option is still here.

Estimate runtime for the Cat C15

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

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Estimated runtime

18.9 hours(0.8 days)

Fuel consumption ≈ 21.14 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 Cat C15 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.

Oil & filter
Every 500 hours or 12 months
Coolant change
Every 6000 hours
Air filter
Every 1000 hours
Fuel filter
Every 500 hours
Major overhaul
20,000 hours
Load bank test
Every 12 months

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 qualityInjector fouling, filter clogging, hard starting4,380+moderate
MEUI injectorsRough running, smoke, power imbalance15,000+moderate
TurbochargerReduced power, oil in intake18,000+moderate
Battery banks (24V)Slow crank, failed 10-second start8,760+minor

Frequently Asked Questions

What is the Cat C15 ACERT?
A 15.2-liter turbocharged-aftercooled inline-6 diesel engine — one of Cat's core power platforms. ACERT (Advanced Combustion Emissions Reduction Technology) is Cat's proprietary combustion approach that achieves Tier 2 emissions without aftertreatment systems.
How does the C15 compare to the Cummins QSK19?
Both are ~500-650 kW inline-6 diesel platforms. The C15 (15.2L) is slightly smaller displacement than the QSK19 (19.0L). Cat's advantage: ACERT combustion technology and deep integration with EMCP controller. Cummins' advantage: larger displacement for better load acceptance and broader dealer network.
What controller does the C15 use?
EMCP 4 (Electronic Modular Control Panel) — Cat's integrated controller with digital metering, protective relaying, and paralleling capability. Unlike open-platform controllers (DSE, ComAp), EMCP is Cat-proprietary and requires Cat dealer tools for deep configuration.
Is the C15 Tier 4 Final?
No — the C15 in standby configuration is EPA Tier 2, which is the applicable standard for stationary emergency engines above 560 kW. No aftertreatment required. Tier 4 Final applies to smaller engines and prime-power applications.

Compatible equipment

More in the Cat C-Series (Diesel)

CAT's broadest diesel lineup: 45–1,500 kW across ten ACERT models for commercial, hospital, and industrial standby.

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