Guardian Series 20kw


Product Description

The Guardian 20 kilowatt generator from Generac Power Systems stands ready 24 hours a day to automatically supply your home with electrical power during unexpected power outages. Working with an automatic transfer switch (purchased separately), the generator starts within seconds of sensing the outage and instructs the transfer switch to move the house onto standby generator power. The 20kw Generac Guardian includes a 5-year, limited consumer warranty, guaranteeing peace of mind for years to come.

Fuel Choices

Natural gas is the typical choice for homes in neighborhoods with a municipal supply and Generac ships their generators configured to run on natural gas. They convert easily to run on LP gas during installation. The generator produces up to 18,000 watts of power running on natural gas and consumes about 205 cubic feet per hour at half load. LP gas produces up to 20,000 watts and half-load consumption runs about 2.1 gallons per hour. Fuel consumption is directly dependent on electrical load and varies continuously as the electrical load changes.


Generac designed its overhead valve industrial engines specifically to meet the demands placed on an engine by a standby generator. The 999cc, 2-cylinder air-cooled engine uses solid-state electronic ignition and engine speed is kept at 3600 RPM for reliable operation and consistent power output.

A fully pressurized lubrication system plus a 200-hour maintenance interval for oil, filter, and plug changes allows the engine to operate reliably for extended periods.

Evolution Controls

The Evolution Controller manages, controls, and monitors all aspects of operation from weekly exercise periods that keep the 6250 generator ready to run, to charging and monitoring the battery and notifying the owner when it needs changing.

If utility power is interrupted, the controller detects the interruption and waits 10 seconds (dealer programmable from 2 to 1500 seconds) to guard against starting during a momentary outage. After it starts the generator engine, it signals the automatic transfer switch to move the home onto standby emergency power.

While the generator is operating, the controller regulates the voltage and engine speed to keep the voltage consistent and the AC frequency at 60 hertz for a continuous supply of utility-quality electrical power. After power is restored, the house is reconnected to the utility supply and controller runs the generator during a cool-down period, then shuts it down.

Mobile Link is an optional accessory that uses the cellular text messaging system to provide you with text message alerts to your cellular phone, and to provide you with access to the generator’s controller from a web-based dashboard. Using a laptop, tablet, or smart phone, you can access your generator from anywhere you have a web connection and program maintenance schedules, view alerts, or even schedule maintenance with your service provider.

Other optional accessories include the basic wireless monitor that displays generator status inside your home, or the advanced model that includes viewing controller messages, programming exercise cycles, and sounds an audible alarm in the event of a malfunction.

Generator Unit

Consistent and clean electrical power, even under the stresses placed on a the generating unit by the operation of large, heavy duty motors, is provided by the generator unit. The revolving magnetic field, stationary armature, and skewed stators with a brush-less design allow a long life, advanced voltage regulation, and power that exceeds the requirements of sensitive electronics while at the same time supplying the high starting currents of air-conditioner motors.

Appearance and Noise

The Generac 20kw Guardian Generator was designed to fit into most suburban neighborhood settings with a pleasing appearance and a low noise level. At just 66 db, it ranks about the same or quieter as most central air units. The Aluminum enclosure resists corrosion, even in salty, coastal climates for a long-lasting finish. The unit ships ready for installation on a gravel bed or concrete slab and measures 48 inches wide, 25 inches deep, and 29 inches high.

Easiest installation on the market and an excellent value when purchased pre-packaged with a pre-wired transfer switch, or customize your system by purchasing the generator and transfer switch separately. Composite pad is included, eliminating the need to pour a concrete base.

Simple field conversion from LP to natural gas.

Generac’s OHVI™ engine was designed specifically for generators. It outruns competitive generator engines with an engine life that is three to four times longer and has a significantly longer period between scheduled maintenance checkups.

Sturdy, galvanneal steel enclosure with RhinoCoat™ finish for superior weather protection.

Electronic Controller and user-friendly LED display and controls for programmable diagnostics and information at-a-glance. Sophisticated codes alert you to generator status at all times.

Added Sound Reduction with enclosures that are lined with sound reducing foam panels for further noise reduction.

True Power™ Electrical Technology

Two Line LCD Multilingual Digital Evolution™ Controller (English/Spanish/French/Portuguese)

Two Transfer Switch Options Available: 100 Amp Pre-Wired Switch or 200 Amp Smart Switch. See Page 4 for Details.

Electronic Governor

External Main Circuit Breaker, System Status & Maintenance, Interval LED Indicators

Sound Attenuated Enclosure

Flexible Fuel Line Connector

Composite Mounting Pad

Natural Gas or LP Gas Operation

5 Year Limited Warranty

Capability to be installed within 18″ of a building*




Models 006244-0, 006250-0

(Aluminum – Gray)

20 kW 60Hz



Install Guidelines


Quick Support ?Quick Support ?
Do you need quick support ?

Enter a question and you will receive an answer shortly...

* required
Send Message