Cummins NTA855 Generator Engine: Complete Specifications, Weight & Fuel Consumption Guide

What Is the Cummins NTA855?

The NTA855 is a 14.0-liter, inline-six, four-stroke diesel engine manufactured by CCEC (Chongqing Cummins Engine Company) for generator-drive applications. It is part of Cummins’ legendary NT-series, which has been in continuous production since the 1970s and has accumulated billions of operating hours across construction, mining, marine, power generation, and heavy-duty trucking.

The “855” in the name refers to the engine’s displacement in cubic inches (855 in³ = 14.0 L). The naming convention breaks down as follows:

The platform’s enduring popularity stems from three design decisions:

1. Mechanical PT fuel system. No ECU, no common rail, no electronic sensors to fail. The Cummins Pressure-Time (PT) pump delivers fuel at injection pressures above 120 MPa with purely mechanical metering. This makes the NTA855 uniquely forgiving in remote locations where diagnostic laptops, high-sulfur fuel, and dusty environments are the norm — not the exception.
2. Replaceable wet cylinder liners. Unlike parent-bore engines that require re-boring the block at overhaul, the NTA855 uses wet liners that can be pressed out and replaced. This dramatically lowers rebuild cost and is the primary reason NTA855 engines remain in service for 20+ years and 15,000+ operating hours.
3. Global parts commonality. Every filter, gasket, injector, and wearable component on the NTA855 shares part numbers with the millions of NT855 engines built for trucks, construction equipment, and marine applications worldwide. Parts are available from Cummins distributors and third-party suppliers in virtually every country on earth.

Complete NTA855 Generator Model Range

CCEC produces 13 distinct NTA855-series G-Drive ratings across turbocharged (T), water-air aftercooled (TA), and air-air charge-cooled (TAA) configurations. Each model below links to its dedicated product page with full data sheets and configuration options.

50 Hz Models (1500 RPM)

60 Hz Models (1800 RPM)

Mechanical Specifications

The following data applies to all NTA855-series engines unless otherwise noted. Performance figures (power, fuel consumption) vary by model rating; physical dimensions and architecture are shared across the range.

Power Ratings Explained: Gross Engine vs. Generator Set Output

There is often confusion between engine brake power (kWm/BHP) and the electricity that actually comes out of the generator terminals (kWe/kVA). The difference is consumed by the alternator, cooling fan, and engine-driven accessories.

Using the NTA855-G4 as an example — data from the official Cummins spec sheet at 1500 rpm (50 Hz):

For the 60 Hz market, the NT855-G6 (a lower-tuned, fuel-optimized variant) provides both 50 Hz and 60 Hz ratings from the official Cummins spec sheet:

ISO 8528 Rating Definitions

A common buyer mistake is specifying a generator by its standby rating when the application requires prime power. Standby-rated engines running continuous duty will experience accelerated wear, wet stacking, and premature overhaul. Always match the rating class to your actual duty cycle.

Fuel Consumption Data (Official Cummins Figures)

Fuel cost accounts for 70–80% of total generator operating expense. The data below comes directly from official Cummins specification sheets — the NTA855-G4 for 50 Hz and the NT855-G6 for both 50 Hz and 60 Hz — measured under ISO 3046 reference conditions.

NTA855-G4 Fuel Map (50 Hz / 1500 rpm)

NT855-G6 Fuel Map (50 Hz and 60 Hz)

Annual Fuel Cost Estimate

Assuming 2,000 operating hours per year at 75% prime load and a diesel price of USD $1.00 per liter:

For remote sites and island nations where diesel often costs $1.30–$1.80 per liter, multiply these figures accordingly. At $1.50/L, a prime-power NTA855 running 2,000 hours per year burns $171,000 in fuel — far exceeding the engine’s purchase price within the first year. This is why proper load sizing matters more than any upfront price negotiation.

Weight, Dimensions & Installation

The NTA855’s compact footprint is one of its key advantages for generator set packagers. The bare engine fits easily in a 20-foot container with alternator and radiator, and its 1,410 kg dry weight does not require specialized rigging equipment.

Complete Generator Set Weight

A complete open-type generator set built around the NTA855 — including alternator, radiator, base fuel tank, steel skid, and control panel — typically weighs:

Installation Notes

• Foundation: A reinforced concrete pad rated for the complete set weight plus 150% dynamic load is recommended. Vibration isolators between the skid and foundation reduce structure-borne noise.
• Fuel tank: A base tank with 8–12 hours of runtime at 75% load requires 460–680 liters capacity for an NTA855-G4 (57 L/h × 8–12 h).
• Exhaust: The NTA855 uses a single Holset turbocharger with a single exhaust outlet. A residential-grade silencer (25–35 dB attenuation) is sufficient for most commercial installations; hospital-grade silencers (35–45 dB) are available for noise-sensitive sites.
• Ventilation: The Coolpac cooling system moves 7.6 m³/s of airflow and is rated for ambient temperatures up to 54.7 °C (G4) or 58.0 °C (G6). Ensure the plant room has adequate intake and exhaust louvers.
• Alternator compatibility: The SAE 1/14 flywheel housing mates with Stamford UCI274, HCI444, and PI144 alternators, as well as equivalent Leroy-Somer and Marathon models covering 250–500 kVA.

NTA855 vs M11 vs KTA19: Which CCEC Engine Do You Need?

The NTA855 sits in the middle of CCEC’s generator-drive lineup. If you are evaluating whether it is the right platform for your project, compare it against its two closest siblings:

For a detailed four-engine comparison including the KTA38 and KTA50, see our NTA855 vs KTA19 vs KTA38 vs KTA50 comparison guide.

Typical Applications

The NTA855’s versatility has made it a fixture across industries. Its mechanical fuel system and robust construction make it particularly well-suited to environments where electronics are a liability rather than an asset.

Maintenance & Service Intervals

The NTA855’s maintenance schedule is straightforward and well-documented. With routine servicing, 12,000–15,000 hours between major overhauls is typical — and standby applications with low running hours can see 20+ years of service.

Parts Availability

One of the NTA855’s greatest strengths is its parts ecosystem. Common wearable components include:

• Filters: Oil filter (LF series), fuel filters (FF series), air filter (AF series) — all spin-on, globally available from Fleetguard and aftermarket manufacturers.
• PT injectors: Camshaft-actuated mechanical injectors; rebuild kits available. Typically last 8,000–12,000 hours before replacement.
• Turbocharger: Holset HX-series; replacement cartridges (CHRA) available for cost-effective repair.
• Water pump: Gear-driven, known for long service life; rebuild kits available.
• Gasket kits: Upper and lower gasket sets cover full in-frame overhaul; inexpensive compared to modern electronic engines.
• Wet liners, pistons, rings: Standard overhaul kit; no machine shop work required on the block.

Genuine CCEC and Fleetguard replacement parts are available through the BLSH Cummins engine parts center and through parts.cummins.com.

Frequently Asked Questions