Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase

The Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase is engineered for reliable standby power in demanding residential, commercial, and light industrial environments. Built around a robust 2.4-liter Cummins engine running at 1800 RPM, this generator delivers stable 3-phase output, low operating noise, and dependable cold-weather performance down to -40°F.

For property owners who need clean 120/240 volts 3-phase power with advanced digital controls and proven durability, the RS25 stands out in the 20–29 kW range. Whether supporting critical business systems, HVAC loads, or agricultural operations, this 25kW standby generator provides consistent voltage regulation and industry-leading diagnostics.

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Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase Overview

The RS25/A051Y400 model is part of the respected Quiet Connect Series. It is UL-2200 listed and EPA-certified for emergency stationary applications. Designed for automatic operation, it integrates seamlessly with an external automatic transfer switch.

Key specifications:

• Rated Output: 25kW

• Voltage: 120/240 Volts 3 Phase

• Rated Amps: 75.2 Amps

• Engine: 2.4L Inline 4-Cylinder Cummins

• Speed: 1800 RPM

• Frequency: 60 Hz

• Sound Level: 69 dBA

• Fuel Type: Natural Gas or Propane

• Enclosure: Aluminum Sound Level 1

• Warranty: Cummins 2-Year Limited Warranty

This model is manufactured in the USA and designed for long service life under continuous standby conditions.

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Engine and Performance: 1800 RPM Liquid-Cooled Reliability

At the core of the Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase is a liquid-cooled 2.4-liter inline 4-cylinder engine.

Why 1800 RPM matters:

• Lower wear compared to 3600 RPM units

• Quieter operation

• Longer maintenance intervals

• Enhanced fuel efficiency

The cast iron block construction increases durability, especially in commercial standby environments. With ±1.0% automatic voltage regulation, sensitive electronics and industrial control systems remain protected during outages.

Fuel flexibility is another strength. The generator can run on:

• Natural Gas (NG)

• Liquid Propane (LP)

Fuel selection is field-configurable during installation.

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120/240 Volts 3 Phase Power Output

The RS25 delivers up to 75.2 amps at 120/240 volts 3-phase, making it ideal for:

• Small commercial buildings

• Agricultural equipment

• Multi-unit residential properties

• Workshops with 3-phase motors

• Light industrial applications

Compared to single-phase generators, 3-phase power provides:

• More efficient motor operation

• Balanced load distribution

• Reduced voltage drop over distance

If your facility operates 3-phase HVAC systems or commercial machinery, this configuration is critical.

For higher voltage applications such as 277/480V systems, consider the Cummins RS125 Quiet Connect 125kW Generator 277/480 Volts 3 Phase.

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Quiet Connect Technology and Sound Attenuation

Noise control is often overlooked when selecting a standby generator. The RS25 operates at just 69 dBA.

The aluminum Sound Level 1 enclosure provides:

• Corrosion resistance

• 180 MPH wind load compliance (ASCE 7-10)

• Easy service access via removable doors

• Enhanced noise suppression

In residential neighborhoods or noise-restricted commercial zones, this low dBA rating is a major advantage.

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PowerCommand 1.1 Digital Control System

The integrated PowerCommand 1.1 control system includes a backlit 128 x 64 LED display.

Features include:

• Remote start/stop capability

• Automatic fault shutdown

• Real-time voltage and frequency monitoring

• Self-diagnostics

• Alarm and status display

• NFPA 110 Level 1 compliance (with required accessories)

This level of system intelligence reduces downtime and simplifies maintenance planning.

From a service perspective, Cummins components are designed for quick access, reducing labor time during routine inspections.

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Cold Weather Performance Down to -40°F

One major differentiator of the Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase is its extreme climate capability.

Factory-installed features include:

• Coolant heater

• Crankcase vent heater

• Large battery rack

• Flexible fuel line

This configuration allows reliable starting in temperatures as low as -40°F, making it ideal for northern climates and high-altitude regions.

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Installation Requirements and Practical Setup Tips

Before installation, consider these key steps:

1. Prepare a level mounting pad.

2. Confirm gas supply sizing matches full-load consumption.

3. Install an appropriately rated automatic transfer switch.

4. Verify local code compliance (UL, NFPA, seismic, emissions).

5. Conduct load calculation to prevent oversizing or undersizing.

Fuel consumption at full load:

• NG: 309.5 cubic feet per hour

• LP: 3.5 gallons per hour

Professional installation is strongly recommended to ensure compliance with local electrical and gas codes.

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Comparing the RS25 to Larger Cummins Quiet Connect Models

If your facility requires higher output, compare the RS25 to larger units in the Quiet Connect lineup:

• Cummins RS125 Quiet Connect 125kW Generator 120/208 Volts 3 Phase

• Cummins RS125 Quiet Connect 125kW Generator 120/240 Volts 3 Phase

Key differences:

If you operate a manufacturing facility or large data center, the RS125 series may be more appropriate. For smaller retail spaces or agricultural shops, the RS25 is more efficient and cost-effective.

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Compliance and Certifications

The RS25 meets major regulatory standards:

• UL-2200

• EPA 40CFR60 Emergency Stationary

• IBC Seismic

• NFPA 110 (with optional accessories)

These certifications are critical for insurance approval and municipal permitting.

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Real-World Application Example

A regional food distribution center required backup power for refrigeration compressors and office systems. Their total calculated load was 19.5 kW with 3-phase motors.

By selecting the Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase, they achieved:

• Adequate startup headroom

• Balanced 3-phase motor support

• Quiet neighborhood operation

• Reduced maintenance due to 1800 RPM engine

This is a textbook case of proper load sizing and system matching.

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Maintenance and Service Intervals

Routine maintenance includes:

• Oil and filter changes

• Coolant inspection

• Battery checks

• Exercise cycle verification

• Control system diagnostics

The flexible exercise mode allows runs as short as 2 minutes every 6 months, reducing unnecessary runtime while maintaining readiness.

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Conclusion: Why Choose the Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase

The Cummins 25kW Generator Quiet Connect Series RS25 120/240 Volts 3 Phase offers a balanced combination of durability, low noise, advanced controls, and fuel flexibility. Its 1800 RPM liquid-cooled engine ensures long service life, while PowerCommand digital integration delivers intelligent standby protection.

For small commercial operations, agricultural facilities, and multi-tenant buildings requiring stable 3-phase power, this model represents a dependable long-term investment.

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1. What voltage does the Cummins 25kW Generator RS25 provide?
It delivers 120/240 volts 3-phase power at up to 75.2 amps.

2. Is the RS25 suitable for commercial use?
Yes. It is designed for residential and light commercial standby applications.

3. Can it operate in extreme cold?
Yes. It starts reliably in temperatures down to -40°F with factory-installed heaters.

4. What fuel types are supported?
Natural gas and propane. The selection is configured during installation.

5. Is it UL listed?
Yes. It meets UL-2200 standards.

6. How loud is the generator?
It operates at approximately 69 dBA.

7. Does it include a transfer switch?
No. The transfer switch is sold separately.

8. What warranty does Cummins provide?
It includes a 2-year limited warranty for consumer and commercial use.