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Generacnew24022LP/NGYes5 Year WarrantyFree Shipping

Generac Guardian Series 6551 22KW/20KW Automatic Home Standby Generator

Item Code: 6551

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Availability: In stock

Regular Price: $4,697.00

Sale Price: $4,462.15

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Quick Overview

Generac  22,000 Watt (LP) / 19,500 Watt (NG) Standby Home Generator, Includes Transfer Switch, Steel Enclosure
Provides essential circuit power protection for your home, ensuring the necessities remain powered during an outage or up to whole house coverage when paired with one of Generacs load shedding devices. Capable of backing up a five ton air conditioner.


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Includes EZ Transfer Switch


When the lights go out you want a fast-acting automatic home standby generator to protect you from power loss. The Generac Model 6551 22,000 Watt (22KW) Air-cooled propane/natural gas powered generator is ideal for home use. Within seconds of losing power this unit starts up automatically without the hassle of manual startup. Packaged and pre-wired with just about everything needed it makes for easy installation and connects to your home's electrical system and existing natural gas fuel supply. So the next time the lights go out, home or away, you're protected by 22,000 watts of standby power.

Hands-Free Automatic Operation 

Nobody wants to venture outside or fumble around in a dark cellar or basement during a storm trying to locate a fuse box. The Generac 6551 is ready to run once all the LP or natural gas connections are hooked up. No manual operation, no fueling and no more extension cords. Within seconds of an outage this generator responds so you don't lose access to heat or refrigeration.

The unit can be programmed to perform a weekly exercise at the time of your choice, so it will be ready for continuous and reliable operation on a moment's notice. For convenience, it also offers clear, digital controls, an at-a-glance status indicator, and an external GFCI outlet to accommodate your outdoor power needs.

Superior Technology for Secure Output, Quiet Operation, and Durability 

Worried about those sensitive electronics and appliances like computers and HVAC equipment? Thanks to Generac's exclusive True Power Technology, this generator provides clean, continuous power so that equipment can be operated without the concern unexpected power surges bring. Disturbing the neighbors isn't an issue either. Thanks to Generac's patented Quiet-Test technology this unit is as quiet as an idling car so nobody has their routine affected.

The generator's aluminum enclosure offers superior corrosion resistance and is protected by Generac's proprietary RhinoCoat system--a unique process that binds the paint to the metal surface for a long-lasting, durable finish. This allows the generator to sit outdoors and withstand harsh weather conditions without developing an unsightly appearance.

Rugged, Worry-Free Design 

Designed to accommodate larger electrical loads the 6551 features the high-performance exclusive air-cooled Generac OHVI® Engine. Able to keep up with rapidly changing conditions this engine optimizes power swiftly and efficiently.

This Generac generator meets CARB requirements. It requires a Group 26R 12-volt minimum 525 CCA battery (sold separately).

What's in the Box?

Generac Guardian Series 6551 22,000 Watt Air-Cooled Propane/Natural Gas Powered Automatic Standby Generator with Aluminum Enclosure; 200 Amp Smart Switch, composite mounting pad; installation guide and owner's manual.

Simple field conversion from natural gas to LP.

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

Trupower Technology provides clean, smooth operation of sensitive electronics and appliances.


Sturdy, Aluminum enclosure with RhinoCoat™ are naturally rust and corrosion resistant. For salt air or high humidity conditions, aluminum is highly recommended to ensure decades of worry free service.

External “At-a-Glance” indicator lights offer an easy way to tell generator status without opening the generator enclosure.

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

Hour Meter monitors run time, providing information to determine maintenance intervals.

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 mounting pad is included, eliminating the need to pour a concrete base.

GENERATOR Model 006551-0 (22 KW)
Rated Maximum Continuous Power Capacity (LP) 22,000 Watts
Rated Maximum Continuous Power Capacity (NG) 19,500 Watts
Rated Voltage 240
Rated Maximum Continuous Load Current – 240 Volts 91.6 LP/86.3 NG
Total Harmonic Distortion Less than 5%
Main Line Circuit Breaker 100 Amp
Phase 1
Number of Rotor Poles 2
Rated AC Frequency 60Hz
Battery Requirement (not included) Group 26R 12 Volts and 525 Cold-cranking Amperes Minimum
Unit Weight (Pounds/Kilos)
Dimensions (L” x W” x H”) 48 x 25 x 29
Sound output in dB(A) at 23 ft. with generator operating at normal load 67
 Sound output in dB(A) at 23 ft with generator in Quiet-Test low-speed exercise mode
Number of Cylinders 2
Displacement 999cc
Cylinder Block Aluminum w/Cast Iron Sleeve
Valve Arrangement Overhead Valve
Ignition System Solid-state w/Magneto
Governor System Electronic
Compression Ratio 9.5:1
Starter 12 Vdc
Oil Capacity Including Filter Approx. 1.9 Qts./1.8L
Operating RPM 3,600
Fuel Consumption
Natural Gas cu.ft./hr.
1/2 Load
Full Load
Liquid Propane ft3/hr (gal/hr)
1/2 Load
Full Load



83 (2.16)
127 (3.68)

Required fuel pressure to generator fuel inlet at all load ranges - 3.5-7" of water column for natural gas, 10-12" of water column for LP gas For BTU content, multiply ft3/hr x 2500(LP) or ft3/hr x 1000(NG)
2-Line Plain Text LCD Display Simple user interface for ease of operation
Mode Switch
Automatic Start on Utility failure. 7 day exerciser
-Off Stops unit. Power is removed. Control and charger still operate.
-Manual/Test (start) Start with starter control, unit stays on. If utility fails, transfer to load takes place.
Programmable start delay between 10-30 seconds Standard
Engine Start Sequence Cyclic cranking: 16 sec. on, 7 rest (90 sec. maximum duration)
Engine Warm-up 5 seconds
Engine Cool-Down 1 minute
Starter Lock-out Starter cannot re-engage until 5 sec. after engine has stopped.
Smart Battery Charger Standard
Automatic Voltage Regulation with Over and Under Voltage Protection Standard
Automatic Low Oil Pressure Shutdown Standard
Overspeed Shutdown Standard, 72Hz
High Temperature Shutdown Standard
Overcrank Protection Standard
Safety Fused Standard
Failure to Transfer Protection Standard
Low Battery Protection Standard
50 Event Run Log Standard
Future Set Capable Exerciser Standard
Incorrect Wiring Protection Standard
Internal Fault Protection Standard
Common External Fault Capability Standard
No. of Poles 2
Current Rating (amps) 200
Voltage Rating (VAC) 120/240,
Utility Voltage Monitor (fixed)
Return to Utility approx. 13 sec.
Exerciser weekly for 12 minutes Standard
UL Listed Standard
Total Of Pre-Wired 16
No. 15A 120V 5
No. 20A 120V 5
No. 20A 240V 1
No. 30A 240V -
No. 40A 240V 1
No. 50A 240V 1
Circuit Breaker Protected
  Available RMS Symmetrical
  Fault Current @250 Volts
5 Year Warranty
  • True Power Electrical Technology
  • Two Line LCD Multilingual - Digital Nexus Controller
  • 200 Amp Smart Switch
  • Electronic Governor
  • External Main Circuit Breaker, System Status & Maintenance Interval LED Indicators
  • Sound Attenuated Enclosure
  • Flexible Fuel Line
  • Composite Mounting Pad
  • Natural Gas or LP Gas Operation
  • 5 year Limited Warranty
  • UL 2200 Listed
  • 26R Wet Cell Battery (NOT INCLUDED)

Sphere 1 allows independent businesses to use their combined purchasing power to attain competitive pricing for the goods and services they use. At a time when the relentless expansion of manufacturer owned distributor networks, large multi yard chains, and big box home improvement retailers is intensifying, independently owned operations have turned to Sphere 1 to help level the playing field with these large competitors.

The Specialty Tools & Fasteners Distributors Association (STAFDA) is a not-for-profit educational trade association comprised of distributors, manufacturers, and rep agents of light construction, industrial, and related products. STAFDA membership also includes publishers of industry trade press (affiliates). STAFDA has 2,500+ members from the U.S., Canada, and overseas.