Overview#
The Cummins RS150 is the largest generator in the QuietConnect RS Series, delivering 150 kW (625 amps at 120/240V single phase) from the QSJ8.9G turbocharged and aftercooled 8.9-liter inline 6-cylinder engine. The RS150 is designed for the most demanding residential applications -- ultra-large estates, multi-structure properties, and facilities that require commercial-grade power in a residential enclosure.
The RS150 runs on natural gas or propane vapor (field selectable) at 1,800 rpm and produces 71.3 dB(A) at 23 feet with the Sound Level 2 powder-coated aluminum enclosure. The enclosure is wind-rated to 180 mph per ASCE 7-10 and the unit is equipped for cold weather starts down to -40 F. An 850-amp CCA battery rated to 0 F is required.
At 3,915 lbs and 143 x 40 x 72 inches, the RS150 shares the same enclosure as the RS125. PowerCommand 2.3 controls provide advanced diagnostics, exercise scheduling (as short as 2 minutes every 6 months), and remote monitoring. Voltage regulation is ±1% and frequency regulation is ±0.25%.
Technical Specifications#
| Parameter | Value |
|---|---|
| Standby Rating | 150 kW |
| Voltage (1-phase) | 120/240V |
| Voltage (3-phase) | 120/208V, 120/240V, 277/480V |
| Frequency | 60 Hz |
| Rated Amps (1-phase 120/240V) | 625 |
| Rated Amps (3-phase 120/208V) | 520.3 |
| Rated Amps (3-phase 277/480V) | 225.3 |
| Rated Amps (3-phase 120/240V) | 450.9 |
| Engine Model | QSJ8.9G |
| Displacement | 8.9 L (543 in³) |
| Cylinders | 6 (inline) |
| Bore x Stroke | 114.1 mm x 144.5 mm |
| Aspiration | Turbocharged and aftercooled |
| Rated Speed | 1,800 rpm |
| Cooling | Liquid-cooled |
| Voltage Regulation | ±1% |
| Frequency Regulation | ±0.25% |
| Starting System | 12V negative ground |
| Battery Capacity | 850 CCA at 0 F |
| Controller | PowerCommand 2.3 |
| Sound Level | 71.3 dB(A) at 23 ft (7 m) |
| Dimensions (L x W x H) | 143.0 x 40.0 x 72.0 in |
| Weight | 3,915 lbs |
| Fuel Pressure | 1.5-3.5 kPa (6.0-13.0 in H₂O) |
| Wind Rating | 180 mph (ASCE 7-10) |
| Cold Weather | -40 F (with factory accessories) |
Our Service Experience#
The RS150 is the flagship of the QuietConnect residential lineup. The QSJ8.9G engine is shared with the commercial C150 N6, and we service both platforms with the same procedures and parts. At 150 kW the engine is running at its maximum rated output on the 8.9L platform, which makes fuel pressure verification under load absolutely critical.
Gas supply sizing is the most common installation issue we see on RS125 and RS150 units. At full load, these generators require substantial gas flow. The gas meter, regulator, supply piping, and any manifold connections must be engineered for the full-load flow rate. A dedicated gas supply line from the meter is strongly recommended. We always verify dynamic fuel pressure with a manometer at the engine inlet during commissioning.
Service intervals are standard for the QuietConnect series: 500 hours or annually for oil and filter, 500 hours for air filter, 1,000 hours for all 6 spark plugs, 30,000 hours for major overhaul. The PowerCommand 2.3 controller provides comprehensive fault logging and operational data that simplifies troubleshooting.
At nearly 4,000 lbs, installation requires engineered structural support. The concrete pad must be designed for the static and dynamic loads. Adequate clearance for service access and cooling air flow must be maintained on all sides.
Frequently Asked Questions#
What is the standby rating of the RS150? 150 kW at 120/240V single phase (625 amps). Also available in multiple three-phase configurations including 120/208V (520.3 amps), 277/480V (225.3 amps), and 120/240V 3-phase (450.9 amps).
How does the RS150 compare to the RS125? Both use the same QSJ8.9G engine in the same enclosure (143 x 40 x 72 in, 3,915 lbs). The RS150 delivers 20% more power (150 kW vs 125 kW). The RS125 runs at a lower percentage of engine capacity, which some owners prefer for longer engine life. The RS150 is the choice when maximum output is needed.
What is the warranty on the RS150? 2-year limited warranty from Cummins. Extended options available through authorized dealers.
