Generac 9933 100A 1ph-120/240V Service Rated Nema 3R Automatic Transfer Switch with Integrated SPD Features:
Generac 9933 100A Service-Rated Automatic Transfer Switch with Surge Protection (1Ø, 120/240V)
The Generac 9933 100 Amp Service-Rated Automatic Transfer Switch with Integrated Surge Protection delivers more than just seamless backup power—it adds an essential layer of whole-home electrical protection. Designed for use with Generac generators utilizing Evolution™ and Power Zone™ 200 controllers, this switch automatically transfers your electrical load to generator power during outages and safely returns it to utility service once power is restored. The result is uninterrupted operation for your home or business, without the need for manual intervention.
What makes this model stand out is its built-in whole-house surge protection device (SPD), engineered to guard against damaging voltage spikes and transients. Instead of requiring a separate surge protection system, this unit integrates protection directly into the transfer switch, helping to shield sensitive electronics, appliances, and electrical systems from unexpected surges. The SPD utilizes thermally protected metal oxide varistors (MOVs), reducing the risk of overheating while providing reliable suppression of high-energy events.
In addition to surge protection, this switch is fully service entrance rated with an integrated utility service disconnect, allowing it to function as the main disconnect point for your electrical system. This simplifies installation, reduces the need for additional components, and helps meet electrical code requirements more efficiently. The open transition transfer design ensures safe switching between power sources, while all sensing, timing, and operational logic are managed by the generator controller for precise and dependable performance.
Built for durability in demanding environments, the Generac 9933 features a NEMA 3R aluminum enclosure with a rugged powder-coated finish, making it suitable for both indoor and outdoor installations. A fast-mount hanging system helps reduce installation time, while the heavy-duty Generac contactor is designed for long-term reliability. With manual operation capability and a 5-year limited warranty, this transfer switch provides a complete, all-in-one solution for automatic power management and surge protection.
Key Features
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100 Amp service-rated automatic transfer switch with integrated surge protection
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120/240V single-phase (1Ø) configuration
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Built-in whole-house surge protection device (SPD) for electrical system protection
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Surge protection uses thermally protected MOV technology to reduce risk of damage
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Service entrance rated with integrated utility service disconnect
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Open transition automatic transfer for safe switching between power sources
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Compatible with Generac Evolution™ and Power Zone™ 200 controllers
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Generator-controlled timing, sensing, and transfer operation
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NEMA 3R aluminum enclosure for indoor/outdoor durability
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Powder-coated finish for corrosion and weather resistance
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Heavy-duty Generac contactor for long service life
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Fast-mount system for quicker installation
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Manual operation capability without power applied
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ETL listed with 10,000 amp withstand rating
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Integrated SPD rated up to 50 kA surge current capacity per phase
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5-year limited warranty
