Overview#
The Cummins QSK23-G3 is an 800-kilowatt standby diesel generator built on the 23.1-liter inline-6 QSK engine — Cummins' purpose-built high-output Quantum series at the upper end of the single inline-6 power range. At 800 kW standby and 727 kW prime (60 Hz), the QSK23 covers large hospitals, industrial facilities, major campus standby, and cost-effective building block for multi-unit paralleling arrays.
The QSK23-G3 uses the Cummins HPI-PT full authority electronic fuel system rather than the MCRS common rail system used in the QSK19, reflecting different engineering paths within the QSK family. The GCS controller for the HPI-PT system is located off-engine in the genset control panel, providing flexible integration and advanced engine protection.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 800 kWe (1000 kVA) |
| Prime Rating | 727 kWe (909 kVA) |
| Continuous Rating | 583 kWe (729 kVA) |
| Frequency | 60 Hz |
| Engine Model | QSK23-G3 |
| Displacement | 23.1 liters |
| Configuration | Cast iron, inline-6 |
| Aspiration | Turbocharged and aftercooled (air-air CAC) |
| Rated Speed | 1800 rpm |
| Starting Voltage | 24V |
| Battery Charging Alternator | 35 amps |
| Lube Oil Capacity | 103 liters |
| Coolant Capacity | 110 liters |
| Limiting Ambient Temp (60 Hz) | 55 °C |
| Engine Length | 2976 mm |
| Engine Width | 1656 mm |
| Engine Height | 1964 mm |
| Engine Dry Weight | 3,245 kg |
Fuel consumption at 1800 rpm (60 Hz):
| Power Level | Load % | L/hr |
|---|---|---|
| Standby | 100 | 212 |
| Prime | 100 | 189 |
| Prime | 75 | 139 |
| Prime | 50 | 97 |
| Prime | 25 | 56 |
| Continuous | 100 | 149 |
Our Service Experience#
The QSK23 is the right choice for single-unit hospital and large campus standby in the 800 kW range. The HPI-PT fuel system provides full authority electronic control with a different maintenance profile than MCRS-equipped engines — injection timing and governor calibration are serviced via the GCS controller rather than through common rail diagnostics. Our service program emphasizes fuel quality management, turbocharger inspection, and load bank testing at or near full rated output annually.
At 800 kW, a marginal turbocharger or degraded fuel will show up under full-load test conditions before it causes a problem during an actual outage. We include fuel sampling, oil analysis, turbocharger inspection, and GCS controller diagnostic review in every annual service event.
Frequently Asked Questions#
What are the QSK23-G3 power ratings at 60 Hz? Standby (ESP): 800 kWe / 1000 kVA. Prime (PRP): 727 kWe / 909 kVA. Continuous (COP): 583 kWe / 729 kVA. Gross engine standby output is 895 kWm (1200 BHP) at 1800 rpm.
What fuel injection system does the QSK23-G3 use? The Cummins High Pressure Injection (HPI) PT full authority electronic fuel system, managed by a G-Drive Governor Control System (GCS) controller located off-engine in the genset control panel.
What turbocharger does the QSK23-G3 use? A Cummins Turbo Technologies (CTT) HX82 unit, with air-air charge air cooling. Coolant capacity is 110 liters; limiting ambient temperature is 55 °C at 60 Hz.
What are the engine dimensions and weight? Engine only: 2976 mm long x 1656 mm wide x 1964 mm tall, dry weight 3,245 kg. Lube oil capacity is 103 liters.
Is the QSK23-G3 suitable for NFPA 110 Level 1 healthcare applications? Yes. The QSK23 with UL 2200 listing and NFPA 110 Level 1 compliance is appropriate for healthcare and life-safety applications when properly installed with a compliant ATS, fuel system, and verified transfer time.
FAQ#
What is the standby rating of the Cummins QSK23?#
The Cummins QSK23-G3 is rated at 800 kW standby / 1000 kVA at 0.8 power factor, 60 Hz, 1800 rpm. Prime rating is 727 kW / 909 kVA. Continuous rating is 583 kW / 729 kVA.
What engine does the Cummins QSK23 use?#
The QSK23 uses the Cummins QSK23-G3 — a 23.1-liter, inline-6-cylinder, turbocharged and aftercooled diesel with the Cummins HPI-PT full authority electronic fuel system managed by a G-Drive Governor Control System (GCS) controller. The QSK23 is non-regulated for stationary emergency standby applications at this power level.
What are the service intervals for the Cummins QSK23?#
Oil and filter changes are due at 500 hours or 12 months. Fuel filter replacement is scheduled at 500-hour intervals. Air filter replacement is due at 1,000-hour intervals. Coolant change is recommended at 6,000 hours or 5 years. Annual load bank testing is recommended. Major overhaul interval is 40,000 hours under standard standby duty conditions.
Is the Cummins QSK23 EPA compliant?#
The QSK23-G3 is non-regulated for stationary emergency standby applications — large stationary emergency generators at this power level are not subject to EPA tier requirements for emergency standby duty. No aftertreatment (DPF/SCR) is required.
Can the Cummins QSK23 be paralleled?#
Yes. The QSK23 with PowerCommand 3.3 controller supports genset-to-genset isochronous load sharing and is used in N+1 paralleling arrays. Medium-voltage (4160V) configurations are available for direct campus distribution connection. It is UL 2200 capable and NFPA 110 Level 1 capable.
What fuel type does the Cummins QSK23 use?#
The QSK23-G3 runs on diesel fuel. The HPI-PT fuel system benefits from high-quality, clean diesel — annual fuel sampling is recommended for standby units. Ultra-low sulphur diesel (ULSD) is compatible.
What is the warranty on the Cummins QSK23?#
Standard Cummins warranty for new generator sets is 2 years or 2,000 hours for standby applications. Extended warranty options are available through Cummins authorized dealers.
