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This generac 100 amp legacy automatic review examines the RXSW100A3 transfer switch. It serves as an automatic whole-home backup solution. The unit features a 100-amp service rating and supports up to 24,000 watts. It handles both 120V and 240V loads across your entire panel. The device includes a built-in Smart AC Module to manage HVAC loads. It operates automatically when utility power fails. You do not need to manually switch sources. This switch is designed for outdoor use with a NEMA 3R aluminum enclosure. It requires a licensed electrician for installation due to its service entrance rating.
- 100 Amp rating supports up to 24,000 watts of power
- Automatic operation senses outages and transfers power without manual input
- Built-in Smart AC Module manages up to four HVAC loads
- Open transition switching prevents backfeed into the utility grid
- NEMA 3R aluminum enclosure withstands outdoor weather exposure
Good fit for
This transfer switch suits homeowners with 100-amp electrical service who want whole-home backup. It is ideal if you need to power large 240V loads like well pumps or dryers. The automatic operation benefits those who prefer not to manage manual interlock kits. It fits users with Generac standby generators featuring Evolution or Nexus controls. The integrated Smart AC Module helps those with multiple air conditioning or heating units. You need a licensed electrician for the required service entrance installation.
Who can skip it
You should skip this unit if your home has a service rating below 100 amps. It will not support your full electrical panel capacity. Avoid this if you plan to use a portable generator from a different brand. This switch is engineered specifically for Generac home standby generators. It lacks integrated surge protection devices, so you may need separate SPD hardware. Do not attempt self-installation. Local code requires a licensed electrician and permit for this service entrance connection.
Verdict
The Generac 100 Amp Legacy Automatic Transfer Switch provides reliable whole-home backup for compatible Generac generators. It is a solid choice for homes with 100-amp service needing automatic power management.
Key Specs Explained For You
Current Rating: 100 Amp
This rating defines the maximum continuous current the switch handles. It supports up to 24,000 watts across your entire panel. You can power large 240V loads like well pumps and dryers. Compare this to smaller manual kits that limit your backup capacity. Higher amp ratings allow more simultaneous use during outages without tripping the system.
Max Wattage: 24000 watts
This figure shows the total power capacity the unit manages. It covers your whole home instead of just a few circuits. You can run essential appliances together when utility power fails. Check your generator output to ensure it matches this limit. This spec helps you avoid overloading the transfer switch during peak demand periods.
Operation Type: Automatic
The switch detects outages and starts your generator without manual input. It transfers power back to your home automatically when utility service returns. You do not need to be home to activate backup power. This differs from manual interlock kits that require physical intervention. Automatic operation provides continuous protection while you sleep or are away.
Voltage: 120V and 240V
This indicates the electrical systems the switch supports for your home. It handles standard 120V outlets and high-demand 240V appliances. You can backup both lighting and heavy equipment like HVAC units. Verify your home panel matches these voltages. This dual capability ensures comprehensive coverage for all your critical loads during extended power failures.
Design and Build Quality
The listing describes the enclosure as powder-coated aluminum. This material choice resists corrosion and moisture. The unit carries a NEMA 3R rating for outdoor exposure. You can mount it outside or in a garage near your main panel. The finish is listed as "No Finish," which aligns with the standard powder-coated exterior. This design ensures reliable performance in various weather conditions.
According to the listing, the physical dimensions are 20 inches in height, 14.6 inches in length, and 7.09 inches in width. The unit weighs 21.9 pounds. These measurements define the space you need for installation. The compact footprint fits standard outdoor mounting areas without requiring excessive clearance. The weight is manageable for a licensed electrician during setup.
The switch includes a Smart AC Module that manages up to four HVAC loads automatically. This module sequences air conditioning or heating loads without extra hardware. Optional Smart Management Modules add circuit control as your needs grow. The operation is fully automatic. It senses an outage and starts your compatible Generac generator. The open transition switching mechanically isolates utility and generator power. This prevents backfeed into the grid. The design prioritizes safety and whole-home coverage for 120V and 240V systems.
Setup And Everyday Use Guide
Installation requires a licensed electrician. This unit functions as a main service disconnect. It ties directly into your utility service. Local codes mandate a permit for this work. You cannot install this switch yourself. The listing ships with the enclosure, contactor, and Smart AC Module. You must purchase the generator and inlet materials separately. This switch is designed specifically for Generac standby generators. It works with Evolution or Nexus controls. It is not compatible with portable units from other brands. Confirm your generator’s controller before ordering. The automatic operation activates the moment utility power fails. The switch senses the outage and starts your generator. It then transfers your entire panel automatically. You do not need to perform any manual interlock actions. Open transition switching mechanically isolates utility and generator power. Both sources never connect at once. This protects line workers and your wiring. The built-in Smart AC Module manages up to four HVAC loads. It sequences these loads without extra hardware. Optional Smart Management Modules add circuit control as your needs grow. The NEMA 3R aluminum enclosure withstands outdoor weather. You can mount it outside or in a garage near your main panel. The powder-coated finish resists corrosion and moisture. Daily use is entirely hands-off. The system handles the transfer and return to utility power. You simply monitor your home’s power status. The 100-amp rating supports your full 120V and 240V panel. You can run large loads like well pumps and dryers. The unit weighs 21.9 pounds. Its dimensions are 7.09 inches wide, 14.6 inches long, and 20 inches high. This size fits standard outdoor mounting locations. The 5-year limited warranty covers the switch mechanism.
Before You Buy This Switch
You need a compatible Generac standby generator with Evolution or Nexus controls. This switch does not work with portable units or other brands. Confirm your generator’s controller before ordering. You must also purchase the inlet box and cord separately, as these are not included in the package. A licensed electrician must handle the installation because this unit serves as your main service disconnect. Local codes require a permit for this work. You cannot install it yourself. The listing includes a five-year limited warranty for the switch mechanism. Routine upkeep involves checking the enclosure for corrosion and ensuring the automatic activation sequence functions correctly during simulated outages. This product fits alongside portable power stations and generators as a permanent home solution. It differs from portable options by providing whole-home coverage without manual intervention. You should verify your home’s electrical panel capacity matches the 100-amp rating. This ensures you can handle up to 24,000 watts across all circuits.
Check before you buy
- Verify your Generac generator uses Evolution or Nexus controls.
- Confirm a licensed electrician can obtain necessary permits.
- Check if you need to buy inlet box separately.
- Ensure your panel supports 100-amp continuous load.
Generac 100 Amp Automatic Transfer Switch
Best for: 100 Amp whole-home automatic backup
- Current Rating
- 100 Amp
- Operation Type
- Automatic
- Circuit Count
- Whole home
- Max Wattage
- 24000 watts
- Voltage
- 120V and 240V
- Enclosure Location
- Outdoor, NEMA 3R
This automatic transfer switch handles up to 100 amps and 24,000 watts across your entire home panel. It senses utility outages and starts your compatible Generac generator without manual intervention. The built-in Smart AC Module manages up to four HVAC loads. Its NEMA 3R aluminum enclosure withstands outdoor weather. You need a licensed electrician for installation because it serves as the main service disconnect.
- 100 Amp rating supports up to 24,000 watts for whole-home backup
- Automatic operation activates the generator the moment power fails
- Built-in Smart AC Module sequences up to four HVAC loads
- NEMA 3R aluminum enclosure resists outdoor corrosion and moisture
- 100 Amp service rating limits total load capacity compared to 200 Amp models
- 21.9 pound weight and 20-inch height require more mounting space
- Requires a licensed electrician for installation due to service entrance rating
- You have a 100 Amp electrical service panel
- You want automatic backup without manual switching
- You need to manage multiple HVAC loads automatically
- You have a 200 Amp service panel needing higher capacity
- You plan to install the switch yourself without a permit
- You use a non-Generac standby generator
Verdict: Generac 100 Amp Automatic Transfer Switch fits homeowners with 100 Amp services who need whole-home backup and automatic HVAC management. It is not suitable for those with 200 Amp panels or those seeking DIY installation.
Specifications side by side
| Spec | Generac 100 Amp Automatic Transfer Switch |
|---|---|
| Current Rating | 100 Amp |
| Operation Type | Automatic |
| Circuit Count | Whole home |
| Max Wattage | 24000 watts |
| Voltage | 120V and 240V |
| Enclosure Location | Outdoor, NEMA 3R |
| Included Components | Enclosure, contactor, Smart AC Module |
| Intended Use | Outdoor |
| Operation | Automatic |
| Dimensions | 14.6 × 7.09 × 20 inches |
| Weight | 21.9 pounds |
| Color | No Finish |
| Model | RXSW100A3 |
Frequently asked questions
Does this transfer switch work with 200 amp panels?
No. This unit is rated for 100 amp services only. It is not suitable for homes with 200 amp electrical panels. You must match the switch rating to your home’s service capacity. Using it with a larger panel could cause safety issues or failure to operate correctly during an outage.
Can I install the Generac 100 amp switch myself?
No. Installation requires a licensed electrician. This unit functions as a main service disconnect and ties directly into your utility service. Local codes mandate a permit for this work. You cannot install this switch yourself due to the high voltage and complexity of the connection.
What size generator does this switch support?
It supports up to 24,000 watts. The 100 amp rating defines the maximum continuous current the switch handles. This capacity allows you to power large 240V loads like well pumps and dryers across your entire panel when the generator is running.
Is this switch compatible with portable generators?
No. You need a compatible Generac standby generator with Evolution or Nexus controls. This switch does not work with portable units or other brands. Confirm your generator’s controller before ordering to ensure proper communication and automatic transfer functionality during power outages.
Does the package include the inlet box and cord?
No. You must purchase the inlet box and cord separately. The listing ships with the enclosure and necessary internal components for the transfer switch itself. Plan your budget and installation plan to include these additional parts for connecting your generator to the system.
What are the physical dimensions of the unit?
The enclosure measures 20 inches in height, 14.6 inches in length, and 7.09 inches in width. It weighs 21.9 pounds. These dimensions allow it to mount outside or in a garage near your main panel, fitting standard residential spaces for automatic backup systems.
