100 Amp Automatic Transfer Switch: Top Picks Reviewed

Introduction to 100 Amp Automatic Transfer Switches

When the power goes out, an automatic transfer switch (ATS) is the unsung hero that seamlessly switches your home or small business from utility power to a backup generator. A 100 amp ATS is a popular choice for residential and light commercial applications, capable of handling essential circuits like lights, outlets, and small appliances. In this article, we review the top 100 amp automatic transfer switches on the market, comparing their features, pros and cons, and overall value. Whether you're installing a standby generator or upgrading your existing setup, this guide will help you make an informed decision.

What to Look for in a 100 Amp ATS

Before diving into our top picks, consider these key factors:

• Type: Service entrance rated vs. non-service entrance. Service entrance models include a main breaker and can be installed between the meter and main panel.
• Switching Mechanism: Contactor-based or molded case switch. Contactor switches are common in residential units, while molded case switches offer higher durability.
• Enclosure: NEMA 1 (indoor) or NEMA 3R (outdoor). Choose based on installation location.
• Generator Compatibility: Ensure the ATS works with your generator's voltage and control system (2-wire start is standard).
• Warranty: Look for at least a 2-year warranty; 5 years is better.
• Certifications: UL 1008 listing is essential for safety and code compliance.

Top 100 Amp Automatic Transfer Switches Reviewed

1. Generac 100 Amp Service Entrance Rated ATS (Model RTSW100A3)

Rating: 4.8/5

Generac's 100 amp service entrance rated ATS is a top contender for homeowners with Generac standby generators. It features a NEMA 3R aluminum enclosure, a 2-wire start, and a 5-year limited warranty. The service entrance rating means it can be installed between the meter and main panel, simplifying wiring and eliminating the need for a separate disconnect.

Pros:

• Seamless integration with Generac generators
• Durable aluminum enclosure for outdoor use
• 5-year warranty
• Service entrance rated (includes main breaker)

Cons:

• Higher price point
• Limited compatibility with non-Generac generators

2. Reliance Controls 100 Amp Transfer Switch (Model 310CRK)

Rating: 4.5/5

Reliance Controls is a trusted name in transfer switches, and the 310CRK is a versatile 100 amp manual transfer switch that can be used with any generator up to 100 amps. It comes with a 10-circuit load center and is designed for indoor use (NEMA 1). While it's manual, it offers a cost-effective solution for those who don't mind flipping a switch during outages.

Pros:

• Compatible with any generator
• Includes 10 pre-wired circuits
• Affordable
• Easy to install for DIYers

Cons:

• Manual operation (not automatic)
• Indoor use only

3. Eaton 100 Amp Automatic Transfer Switch (Model EGS100L24R)

Rating: 4.7/5

Eaton's EGS100L24R is a 100 amp automatic transfer switch with a NEMA 3R enclosure, suitable for outdoor installation. It features a molded case switch for reliable performance and is compatible with most generators with 2-wire start. The switch is UL 1008 listed and comes with a 2-year warranty.

Pros:

• Molded case switch for durability
• Outdoor-rated enclosure
• Compatible with many generator brands
• Reliable Eaton quality

Cons:

• Shorter warranty compared to some competitors
• No service entrance rating

4. Kohler 100 Amp Automatic Transfer Switch (Model KSS100R)

Rating: 4.6/5

Kohler's KSS100R is a service entrance rated ATS designed for Kohler generators but also works with other brands. It has a NEMA 3R enclosure, a 5-year warranty, and a robust contactor design. The switch includes a main breaker and is ideal for whole-house backup when paired with a Kohler generator.

Pros:

• Service entrance rated
• 5-year warranty
• Excellent build quality
• Works with Kohler and other generators

Cons:

• Premium price
• Limited availability in some regions

5. Briggs & Stratton 100 Amp Automatic Transfer Switch (Model 071000)

Rating: 4.4/5

Briggs & Stratton's 100 amp ATS is a budget-friendly option for those with Briggs & Stratton standby generators. It features a NEMA 3R enclosure, 2-wire start, and a 2-year warranty. While it lacks the service entrance rating, it's a solid choice for basic backup power.

Pros:

• Affordable
• Outdoor-rated
• Simple installation

Cons:

• 2-year warranty only
• Not service entrance rated
• Best with Briggs & Stratton generators

Comparison Table

Recommendations

Based on our review, the Generac RTSW100A3 is our top pick for its service entrance rating, robust build, and excellent warranty, especially if you own a Generac generator. For those on a budget, the Reliance Controls 310CRK offers great value for manual operation, while the Eaton EGS100L24R is a reliable automatic option for outdoor installations. If you have a Kohler generator, the Kohler KSS100R is a perfect match. Ultimately, choose a switch that is compatible with your generator and meets your installation requirements.

Conclusion

A 100 amp automatic transfer switch is a critical component of any backup power system. By considering the factors outlined and our top picks, you can confidently select the right ATS for your needs. Always consult a licensed electrician for installation to ensure safety and code compliance.