Generac RXGW20SHA3 200A 1ph-120/240V Service Rated Nema 3R Automatic Transfer Switch with 20-40 Circuit Load Center

Generac RXGW20SHA3 200A 1ph-120/240V Service Rated Nema 3R Automatic Transfer Switch with 20-40 Circuit Load Center Features:

Generac RXGW20SHA3 200A Automatic Transfer Switch Features:

The Generac RXGW20SHA3 is a full-featured, high-capacity automatic transfer switch designed for whole-home power backup with built-in load center functionality. Rated at 200 amps, this service-entrance switch can serve as your main disconnect so long as local codes allow. It combines an ATS and a 20-space load center in one weather-rated, rugged enclosure—making it ideal for homes that want essential circuits protected without adding separate panels.

One of the standout features is its built-in load center, which accepts standard, GFCI, AFCI, or tandem breakers from brands like Siemens, Eaton, Square D, and more. While the panel has 20 spaces, tandem breakers allow you to expand support up to 40 circuits when needed, giving flexibility for growth or additional branch circuits. Pass-through lugs let you run power onward to your main distribution panel or outbuildings as needed.

This switch also includes intelligent load management: the integrated Smart A/C Module (SACM) enables management of up to four HVAC loads (24VAC) without needing extra hardware. If more load control is required, external Smart Management Modules (SMMs) allow even more loads to be managed—helpful for optimizing generator sizing and reducing total cost. Housed in an aluminum NEMA 3R enclosure with powder-coated finish, it’s built for outdoor or indoor installation with solid protection against rain, snow, ice, and debris.

Finally, this model operates with open-transition switching—meaning utility is disconnected before the generator powers up, which helps protect equipment and prevents overlap. It’s designed to work with Generac’s Evolution™ or Nexus™ generator controllers to handle all timing, sensing, and automatic switching, backed by a 5-year limited warranty.

Key Features

• 200 Amp service-entrance rated automatic transfer switch (single-phase 120/240V)

• Integrated 20-space load center; supports up to 40 circuits with tandem breakers

• Built-in Smart A/C Module (SACM) for managing up to 4 HVAC loads without extra hardware

• Compatible with optional Smart Management Modules for more load control

• Pass-through lugs for feeding sub-panels or outbuildings

• Aluminum NEMA 3R enclosure suitable for outdoor or indoor use, powder-coated finish

• Open-transition switch: utility power disconnects fully before generator powers loads

• Heavy-duty contactor and rugged components, sized for high usage

• Works with Generac Evolution™ or Nexus™ controllers (handles voltage sensing, delay timers, etc.)

• Wire range up to 300 MCM copper/aluminum conductors

• Withstand rating ~22,000 amps for transient fault protection

• Dimensions approx 38.5″ H × 17.6″ W × 8.0″ D; weight ~45 lbs

• 5-year limited warranty

RXGW20SHA3 Specifications Sheet
RXGW20SHA3 Owner's Manual
RXGW20SHA3 Warranty