Cummins
Cummins QSJ5.9G
QSJ
Cummins QSJ5.9G is a 5.9 L inline-6 spark-ignited natural-gas generator engine. Cummins lists G1, G2 and G3 ratings in EPA NSPS-certified 60 Hz sets from 45 to 100 kWe; EPA annual certification data lists up to 123.8 kWm at 1800 RPM.
Overhaul & repair parts- Manufacturer files
- 1 datasheet
- Last updated
- 2026-07-25
- Package route
- gas generator sets
- Standby Power · 60 Hz
- 125 kVA
- Electrical Output
- 100 kWe
- Cylinders
- L6
- Displacement
- 5.9 L
- Rated Speed
- 1,800 RPM
Power Ratings
kWm = mechanical shaft power · kWe = electrical output · kVA = kWe ÷ 0.8 pf
60 Hz1800 RPM
| kWm | kWe | kVA | |
|---|---|---|---|
| Standby Power | — | 100 | 125 |
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Cummins QSJ5.9G generator set context
The Cummins QSJ5.9G is listed here as a natural gas generator-drive engine for 60 Hz generator sets, with a headline 125 kVA / 100 kWe / standby rating. Use this page to compare the published engine output, electrical kWe/kVA ratings, emissions level, datasheet availability, and neighboring models before specifying an alternator, controller, enclosure, voltage, and compliance package.
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Technical Specifications
| Brand | Cummins |
| Model | QSJ5.9G |
| Series | QSJ |
| Configuration | L6 Turbocharged Spark Ignition |
| Cylinders | 6 |
| Displacement | 5.9 L |
| Fuel Type | Natural Gas |
| Ignition Type | Spark Ignition |
| Cooling Method | Liquid-Cooled |
| Emissions Standard | U.S. EPA Stationary |
| Certifications | U.S. EPA NSPS |
| Country of Origin | United States |
Frequently asked questions
What is the power output of the Cummins QSJ5.9G?
The Cummins QSJ5.9G is rated at 125 kVA standby at 60 Hz (1,800 rpm).
Does the QSJ5.9G run at 50 Hz or 60 Hz?
The Cummins QSJ5.9G is rated for 60 Hz (1,800 rpm).
What fuel does the Cummins QSJ5.9G use?
The Cummins QSJ5.9G is a Natural Gas generator-set engine.
What is the displacement and cylinder configuration of the QSJ5.9G?
The Cummins QSJ5.9G is an inline-6 (6-cylinder) engine with a displacement of 5.9 L.
What emissions information is listed for the QSJ5.9G?
This record lists U.S. EPA Stationary for the Cummins QSJ5.9G. Confirm the exact engine family, model year, configuration and applicable manufacturer certification documents before specifying it for a regulated project. A database label does not establish certification of a complete generator package.
What is the catalog status of the Cummins QSJ5.9G?
The Cummins QSJ5.9G is marked active in this database. Confirm current production and availability with the manufacturer; catalog status is not a live supply check.
Are reference documents available for the QSJ5.9G?
This page links reference documents for the Cummins QSJ5.9G. Check each document's title, model coverage, revision and rating conditions before using it for selection.