Cummins RS30 Generator: Specs and Model Overview
The Cummins RS30 is rated 30kW on natural gas and 30kW on propane. It uses a QSJ2.4, 2.4L turbocharged and aftercooled inline-four engine at 1,800 rpm. It fits properties whose simultaneous demand justifies 30kW and the fuel supply and footprint of a liquid-cooled system.
Cummins RS30 questions answered: sizing, cost, fuel and maintenance
Cummins RS30 Specifications
| Specification | Cummins RS30 |
|---|---|
| Natural-gas / propane output | 30 / 30 kW |
| Rated current at 240V, NG / LP | 125.0 / 125.0 A |
| Engine | QSJ2.4, 2.4L turbocharged and aftercooled inline-four |
| Speed | 1,800 rpm |
| Weight | 1,231 lb |
| Main generator breaker | 150 A |
| NG at half / full load | 219 / 380.9 ft³/hr |
| LP vapor at half / full load | 95.9 / 164.1 ft³/hr |
| Dimensions, L × W × H | 94 × 34 × 45.5 in |
| Published Sound Level 1 | 65 dBA at 23 ft |
| Controller | PowerCommand 1.1 |
| Starting battery | 12V negative ground; manufacturer lists 550A capacity at 0–32°F |
Scope: U.S. 120/240V single-phase, 60Hz. Figures follow NAS-5776-EN, July 2021; altitude, temperature, fuel quality and ordered options may change performance. Confirm the supplied unit’s specification and serial-number documentation.
Where the RS30 Fits
Choose from simultaneous running loads and the largest motor start. The fuel-specific rating is a continuous-output ceiling; a starting kVA figure describes a brief transient. A transfer switch connected to the whole service does not guarantee all appliances can run together.
The RS30 fits properties whose simultaneous demand justifies 30kW and the fuel supply and footprint of a liquid-cooled system. Include HVAC compressor starts, pumps, electric heat and EV charging in the load plan. Use the generator size calculator to organize the list, then have an installer validate it.
Cost and Installation Scope
Get an itemized local installed quote; an equipment price does not cover the complete project. No verified current model-specific retail price is asserted here. Require separate line items for the generator and options, automatic transfer switch, battery, delivery and lifting, foundation, electrical work, fuel piping or tank, permits, commissioning and any meter upgrade or load controls. Compare equal scopes from qualified local installers. Remote siting, trenching, service changes and cold-weather accessories can materially change the total. Our whole-house generator cost guide explains the scope to compare.
Transfer Switch and Fuel Supply
Confirm the exact package and transfer-switch model in writing. The liquid-cooled specification lists the automatic transfer switch as sold separately. Have the installer specify amperage, voltage, phase, service-entrance rating, number of panels and any load-management controls. The generator’s output amperage and the utility-service or ATS rating are different design limits.
Source: Cummins NAS-5776-EN, July 2021 specification.
At full load, the linked table gives 380.9 ft³/hr on natural gas and 164.1 ft³/hr on LP vapor. Confirm combined appliance demand and pressure at the generator, with the gas utility or propane supplier involved where necessary.
Ownership and Service
For the Spec A QSJ2.4 units covered by A045R242 Issue 12, oil and filter service is due after the first 50 hours, then every 200 hours; the table also specifies the annual interval, whichever comes first. Check oil and coolant daily or every 24 operating hours. The manual lists air-cleaner replacement at 100 hours, spark-plug inspection at one year/200 hours, and coolant replacement at two years. This July 2018 manual explicitly covers C30 N6 and C36 N6 Spec A; do not apply its schedule automatically to Spec B or another revision. Have the servicing dealer supply the serial-specific manual and confirm any updated schedule.
Source: Cummins operator manual A045R242, Issue 12 (Spec A).
Compare Cummins Models
Sources and Model Verification
These are manufacturer-authored documents; some PDFs are hosted by suppliers. Specifications are revision-specific. Confirm the ordered model, serial number, spec letter, voltage, phase, fuel, enclosure and warranty statement with the dealer. The linked liquid-cooled operator manual applies to Spec A, and should not substitute for a later unit’s service instructions. Confirm current equipment and installation pricing in a written local quote.