The Generac RXSW100A3 Automatic Transfer Switch is a 100 amp residential transfer switch built for home standby generator systems. This is a transfer switch designed for automatically moving electrical load from utility power to generator power during an outage. Model Number: RXSW100A3. If you are setting up a single-phase standby system and want service-rated switching with automatic operation, this is the part that makes the whole backup setup work the way it should.

What matters most here is that the switch continuously monitors incoming utility power and transfers the load automatically when power fails or drops to an unacceptable level. When utility power comes back and stabilizes, it transfers the load back. In real use, that means your backup generator system is not just about having power available, but about having the handoff happen without you needing to walk outside, throw a switch, or manage the transition yourself.

The 100 amp rating makes this a practical fit for residential standby generator installations that need service entrance rated switching. Generac also states this switch has a built-in service disconnect breaker and is approved as a service entrance disconnect in the Canadian version of this product family. For buyers comparing transfer switches, that service-rated design matters because it combines transfer function and service disconnect capability into one piece of equipment instead of turning the job into a patchwork of added components.

One of the stronger features on this unit is the integrated DPM load management system. It can manage up to four individual 24 VAC HVAC loads without additional accessories. That is not just a spec-sheet talking point. It gives the installer more flexibility when balancing the house load against available generator output, and it can help avoid oversizing the generator just to accommodate peak air conditioning demand. If the goal is a smarter standby setup, this is one of the features that earns its keep.

Generac uses a NEMA 3R aluminum enclosure for this switch, and that matters on the install side. NEMA 3R means it is outdoor rated and built to protect internal components from weather exposure like rain, snow, ice, and debris. The aluminum enclosure also helps with corrosion resistance. For homeowners and installers deciding whether the switch can be mounted outside near the generator or service equipment, this rating gives you more placement flexibility.

From a system standpoint, this transfer switch is designed for compatible single-phase generator systems. Supplementary product data also notes use with single-phase generators that utilize an Evolution or Nexus controller. That makes compatibility an important check before ordering. If you are already in the Generac home standby ecosystem, this switch is aimed at that application, not at a generic portable generator setup.

Physically, the unit is compact enough for typical residential installation work, with listed dimensions of 14.6 x 7.09 x 20 inches and a weight around 21.85 pounds. It uses screw terminals and is described as panel mount. Those details are not glamorous, but they matter to the installer who needs a transfer switch that is straightforward to position, wire, and integrate into a standby power system without wasting wall space.

Who should buy it? This is for residential standby generator installations, generator dealers, electricians, and homeowners working with a qualified installer who need an automatic transfer switch for a 100 amp single-phase setup. If you want manual operation, this is not your product. If you want automatic standby operation, service-rated capability, weather-ready housing, and built-in load management for HVAC circuits, the Generac RXSW100A3 Automatic Transfer Switch checks the boxes that actually matter.

Generac RXSW100A3 Automatic Transfer Switch for a Clean Standby Setup

If you are building a proper residential standby system, this is the kind of transfer switch that keeps the install clean and the backup experience automatic.

• Who it's for: Homeowners and installers putting together a 100 amp single-phase standby generator system with automatic transfer capability.
• Why it stands out: Service entrance rated design, NEMA 3R aluminum enclosure, and built-in load management for up to four HVAC loads without extra hardware.
• Worth knowing: This is meant for compatible standby generator systems, so controller and generator compatibility should be confirmed before ordering. It is not a one-size-fits-all portable generator transfer solution.

• Is this an automatic or manual transfer switch? It is an automatic transfer switch that monitors utility power and transfers to generator power during an outage.
• What generator systems is it designed for? It is designed for compatible single-phase standby generator systems. Supplementary data also references use with Generac single-phase generators using Evolution or Nexus controllers.
• Can it be installed outdoors? Yes. The enclosure is rated NEMA 3R and described for indoor or outdoor installation.
• Can it manage air conditioning loads? Yes. Integrated DPM load management can manage up to four 24 VAC HVAC loads without additional hardware.