PowerProtect™ DX 20kW Standby Generator Product Image

PowerProtect™ DX 20kW Standby Generator

Model Number: 40657

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The 20kW1 DX generator is there when you need it most, providing more power on both natural gas and liquid propane than any other generator in its class. The workhorse of the PowerProtectDX lineup, the 20kW unit is backed by the most comprehensive warranty over time with a 10-Year limited warranty.

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Available Models: 40657

Product Details


Highest-Rated Power Output in its Class

Get more bang for your buck with the most powerful natural gas unit in its class.2

Best-In-Class Warranty

10-Year limited warranty3 of parts, labor, and travel, included for the entire term. The industry’s most comprehensive warranty over time is standard to give you piece of mind that you have the coverage you need.

Quiet Weekly Test Mode

Over 65% quieter during weekly test mode, for less disruption to you and your neighbors.4

Multiple Fuel Options

Optimized for both natural gas and liquid propane fuels, the PPDX20 can provide reliable backup power to your home regardless of your available fuel options.

Commercial-Grade Vanguard® Power

Rugged, reliable engines trusted for the most demanding commercial applications, so you always get the power you need.

Easy Installation & Serviceability

Approved for installation as close as 18" to a building for flexibility of placement around the home - simple toolless panel removal also allows for easy serviceability and maintenance.5

Assembled & Engineered in USA

Briggs & Stratton generators are designed and assembled in the USA.6

Power Management System (Optional)

Customizable to your home's power needs, Symphony® II and Amplify Power Management systems offer prioritized whole house power giving flexibility to a more affordable standby generator solution.

Corrosion Resistant Enclosure & Base

Automotive-grade galvanneal steel base and aluminum enclosure to resist rust, and powder-coated paint for years of protection against chips and abrasions.

Superior Customer Support

When you need support, we've got your back with a nationwide call center and dealer network. Our best-in-class customer service team is always prepared to assist with any questions you may have.

1This generator is listed in accordance with UL (Underwriters Laboratories) 2200 (stationary engine generator assemblies) and CSA (Canadian Standards Association) standard C22.2 No.100-14 (motors and generators).
2On natural gas in its named class
3See operator’s manual for complete warranty details.
4Compared to full load based on lowest microphone at 7 meters
5The installation manual contains specific instructions related to generator placement in addition to NFPA 37, including the requirement that carbon monoxide detectors be installed and maintained in your home or business.
6Of U.S. and global parts

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PowerProtect™ DX 20kW Standby Generator

Model Number 40657
Running Watts (Liquid Propane) kW** 20
Running Watts (Natural Gas) kW** 20
Running Amperage (Liquid Propane) Amps** 83.3
Running Amperage (Natural Gas) Amps** 83.3
Voltage 120 / 240
Circuit Breaker Amps 100
Engine Brand Vanguard®
Engine Displacement (cc) 993
Assembled Length (in.) 46.5
Assembled Width (in.) 26.8
Assembled Height (in.) 28.4
Assembled Weight (lbs.) 520
Normal Operating Sound 68 dBA
Fuel Consumption (Liquid Propane) (50% Load, BTU/hr)*** 208,000
Fuel Consumption (Natural Gas) (50% Load, BTU/hr)*** 187,000
Limited Warranty (Years)† 10

**This generator is rated in accordance with UL (Underwriters Laboratories) 2200 (stationary engine generator assemblies) and CSA (Canadian Standards Association) standard C22.2 No.100-14 (motors and generators).

***Fuel consumption rates are estimated based on normal operating conditions. Generator operation may be greatly affected by elevation and the cycling operation of multiple electrical appliances - fuel flow rates may vary depending on these factors.

†See operator’s manual for complete warranty details.

Category Description

Automatic Transfer Switches

This device stands guard and senses when utility power flowing to your home is interrupted, then automatically turns on your Briggs & Stratton standby generator

Power Management

Make your backup power go further with a power management system. It prioritizes power for what you really need, reduces fuel costs and allows you to use a smaller-size generator to power your home

Amplify Power Management

Symphony® II Power Management

Generator Monitoring Systems

Finally, there’s no need to run outside to check on your home generator when a storm is looming. Briggs & Stratton monitoring systems are popular generator accessories that make it more convenient than ever to stay on top of your generator’s current status without ever leaving the comfort of your living room.

InfoHub™ Wireless Generator Monitoring

Remote System Status Panel for Generator Monitoring

Basic Wireless Generator Monitor

Wireless Router for Generator Monitoring

Generator Maintenance Kits

Keep your Briggs & Stratton home generator running at peak performance and ready when it's needed.

Cold Weather Accessories

Keep your Briggs & Stratton generator ready to perform like normal even when the temperature dips below 30°F outside. Your dealer can suggest the best generator cold weather kit for your system when your generator is installed. Learn more about the available options below.

Home Generator Cold Weather Kits

Engine Block Heater

240-Volt Internal Battery Warmer

240-Volt Internal Engine Oil Warmer

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