Best Lockout Switches for Generators: Safe, Easy Power Transfer Solutions
When choosing a generator lockout switch, the key is safety, compatibility, and ease of installation. This guide covers top options for residential and small commercial setups, helping you decide which interlock or transfer switch best fits your panel type and wiring needs. The right device prevents backfeeding, protects utilities, and ensures a smooth switch between utility power and generator power. Ideal buyers include DIY homeowners upgrading a main panel, contractors installing portable power, and building managers seeking reliable backfeed protection.
| Product | Panel Type | Spacing | Best For |
|---|---|---|---|
| MOWABI Generator Interlock Kit | Square D QO / Homeline 150-200A | 1 3/8 inches | Main and generator integration with reliable materials |
| EZ Generator Switch | General transfer switch (UL/CSA approved) | N/A | Original, US-made transfer switch for quick power transfer |
| CZNZN Interlock Kit | Square D QO / Homeline 150-200A | 1-3/8 inches | Front-mount interlock for backfeeding safety |
| LATING GE Interlock | GE 150/200A panels | 1 1/4 inches | Durable anodized aluminum for outdoor use |
| Kohree Transfer Switch | 5000-series style? 15A transfer | N/A | Indoor/outdoor 15A standby power |
Below, five top options are analyzed for compatibility, safety features, and installation clarity. Each entry notes who benefits most, along with practical cautions to help you compare quickly.
MOWABI Generator Interlock Kit for Square D QO/Homeline
This interlock kit is designed for Square D QO or Homeline 150-200A panels. It uses a 1 3/8 inch spacing between the main and generator breakers for a precise fit. It combines premium materials, including M35 cobalt drill bits and Inox 304 hardware, with aluminum components to resist bending and warping. Best for homeowners upgrading a compatible panel or contractors focusing on a durable, long-lasting solution. Caution: installation requires accurate spacing and access to the panel’s interior wiring; ensure you follow the included instructions.
EZ GENERATOR SWITCH
The EZ Generator Switch is the original, patented manual transfer switch, UL/CSA/ETL approved and made in the USA. It’s a strong choice for buyers seeking a trusted, established transfer solution with direct manufacturer support. Best for buyers who want a readily available, US-made option with a clear transfer workflow. Caution: this product represents a transfer switch rather than a front-mounted interlock; installation scenarios differ from interlock kits.
CZNZN Interlock Kit for Square D QO/Homeline
This UL-tested interlock kit fits Square D QO or Homeline 150/200A panels with 1-3/8 inch spacing. It mounts on the front of the breaker panel and uses a lock plate to switch between utility and generator power. Best for homeowners who want a UL-verified option with clear generator lockout positioning. Caution: while robust, it requires precise mounting alignment and proper sealing for outdoor use.
LATING GE Interlock Kit
Designed for General Electric 150 or 200A panels, this interlock kit features a 1/4 inch spacing and anodized aluminum construction for increased durability and insulation. It’s a practical choice for outdoor installations where corrosion resistance matters. Best for GE panel users needing a reliable, corrosion-resistant interlock. Caution: may require professional wiring to ensure safe backfeeding and compliance with local codes.
Kohree Transfer Switch 15A
The Kohree 15A transfer switch is ETL-listed and designed for indoor/outdoor use with a 15A, 125V inlet and predrilled holes for easy installation. Best for small properties or backup systems needing a simple, compliant transfer switch for a standard generator connection. Caution: designed for 15A circuits; higher loads require a larger transfer setup compatible with your panel and generator capacity.
CZNZN Generator Lockout Kit for EaT/Cutler Hammer BR
This UL-tested interlock kit targets EaT/Cutler Hammer BR Series 150/200A panels with 1 1/4 to 1 7/16 inch spacing. It’s a front-mount solution that prevents both utility and generator power from running simultaneously. Best for owners of CH BR panels who need a compliant, front-mounted lockout. Caution: installation must respect exact spacing; not universal across all panel brands.
Buying Guide: Key Considerations For Lockout Switches
- Panel compatibility: Verify your panel model (Square D QO/Homeline, GE, Cutler Hammer BR, etc.) and confirm the required spacing between breakers.
- Type of device: Interlock kits prevent simultaneous utility/generator operation, while transfer switches require manual or automatic switching. Choose based on how you want the transfer to occur.
- Outdoor vs indoor use: If the installation is outdoors, select corrosion-resistant materials and weather-rated enclosures if needed.
- Installation complexity: Some kits mount on the front of the panel; others require cutting, drilling, or additional wiring. Consider whether you’ll DIY or hire a professional.
- UL/ETL listings: For code compliance and safety, prefer UL-listed/ETL-listed devices validated for electrical safety standards.
- Load and generator compatibility: Ensure the device supports your generator’s output and the home’s critical loads you intend to backfeed.
Frequently Asked Questions
- What is a lockout interlock switch used for? It prevents backfeeding by ensuring the main breaker and generator breaker cannot be on at the same time.
- Do I need a transfer switch if I have an interlock kit? Not necessarily; interlocks and transfer switches serve related but distinct purposes. Some setups use transfer switches for automatic power transfer, while interlocks focus on safe sequencing.
- Is a UL listing important for generator lockout devices? Yes, UL or ETL listings indicate conformity to established safety standards, which is beneficial for code compliance and safety.
- Can these devices be installed outdoors? Some are rated for outdoor use; check the product’s mounting recommendations and weather resistance.
- Do I need an electrician to install these? Installation complexity varies; some kits are DIY-friendly with detailed instructions, while others may require professional wiring.
- What spacing should I expect between main and generator breakers? Spacing options shown here include 1-3/8 inches and 1-1/4 inches, depending on panel model and kit design.