Best Main Breaker Lockout for Generator: Top 5 Interlock Kits
Choosing a reliable main breaker lockout kit helps safely backfeed a portable generator while keeping utility power and generator power from running simultaneously. This guide reviews five highly compatible interlock kits designed for 150- and 200-amp panels from leading manufacturers, focusing on fit, materials, and installation ease to support stable home backup power solutions.
| Product | Brand | Panel Compatibility | Spacing | Notes |
|---|---|---|---|---|
| MOWABI Generator Interlock Kit | MOWABI | Square D QO/Homeline 150-200A | 1 3/8 inches | Premium materials, easy install |
| Natupal Generator Interlock Kit | Natupal | Square D QO/Homeline 150-200A | 1 3/8 inches | Professional grade interlock |
| CZNZN Generator Interlock Kit | CZNZN | Square D QO/Homeline 150-200A | 1 3/8 inches | UL tested, indoor/outdoor ready |
| EXCELFU GE Interlock Kit | EXCELFU | GE 150/200A Panels | 1 1/4 inches | Safe backfeeding for GE panels |
| Toptozl Eaton BR CH/BR Interlock Kit | Toptozl | Eaton BR/CH 150/200A | 1 1/4 – 1 7/16 inches | Durable aluminum construction |
Below are five detailed product sections to help compare features, installation, and suitability for typical home backup power setups. Each entry includes a direct link to the product page, an image, and key features from the listing.
MOWABI Interlock Kit for Square D QO/Homeline
The MOWABI Generator Interlock Kit is designed for Square D QO or Homeline panels rated 150 to 200 amps. It uses high-quality materials including M35 cobalt drill bits, Inox 304 screws, nuts, and alloy aluminum to resist bending and warping, aiming for long-term reliability. The kit specifies a 1 3/8 inch spacing between the main and generator breaker, ensuring a proper fit and seamless integration. It includes a drill bit and installation instructions to facilitate a straightforward setup.
Natupal Interlock Kit for Square D QO/Homeline
The Natupal interlock kit is compatible with Square D QO or Homeline 150-200 amp panels and requires 1 3/8 inch spacing between the main and generator breakers. It is marketed as a professional-grade safety solution to safely direct generator power to home circuits during outages, reducing the risk of backfeed and improving reliability during emergencies.
CZNZN Interlock Kit for QO/Homeline
CZNZN’s interlock kit is intended for Square D QO or Homeline panels (150 or 200A). It specifies an interval spacing of 1 3/8 inches between the main and generator breakers and can be mounted on the front of the breaker panel. The kit is described as UL tested and suitable for indoor or outdoor use, with a manual lockout transfer-switch feature to manage power sources during outages and to clearly indicate the active power source.
EXCELFU Interlock Kit for GE Panels
EXCELFU offers a generator interlock kit compatible with General Electric GE 150 or 200 amp panels. The kit specifies a 1 1/4 inch spacing between the main breaker and branch breakers, aimed at safe backfeeding and ensuring all household appliances can be powered during outages. The kit focuses on safe and reliable operation, reducing the risk of simultaneous mains and generator power.
Toptozl Interlock Kit for Eaton BR/CH Series
Toptozl’s generator interlock kit supports Eaton Cutler-Hammer BR and CH series panels rated 150 or 200 amp. It features spacing between main and branch breakers in the range of 1 1/4 to 1 7/16 inches and uses sturdy aluminum alloy for durability. The kit is designed for easy installation and durable performance in both indoor and outdoor environments, enabling safe switching between utility and generator power during outages.
Buying Guide: Key Purchase Considerations
- Panel compatibility: Ensure the interlock kit is specifically rated for your panel brand and model (Square D QO/Homeline, GE, Eaton BR/CH, etc.).
- Spacing accuracy: Common spacings are 1 3/8 inches or 1 1/4 inches between main and generator breakers. Confirm your panel’s space and the kit’s tolerance for a proper fit.
- Installation complexity: Look for kits with included hardware (drill bits, screws) and clear instructions to simplify installation and reduce the risk of misalignment.
- Durability and materials: Aluminum or alloy plates with corrosion resistance improve longevity, especially in outdoor installations.
- UL or safety certifications: UL testing or other safety certifications provide additional assurance of safe operation during backfeeding.
- Lockout and transfer features: Some kits include manual transfer-switch functionality to clearly indicate power source and prevent backfeed.
- Indoor vs outdoor use: Consider environmental exposure and choose a kit rated for the intended mounting location.
- Maintenance and serviceability: Favor kits with straightforward inspection access and replacement parts to support long-term reliability.
- Cost vs risk: Evaluate the potential risk reductions from a properly installed interlock kit against installation costs and future panel upgrades.
- Warranty and vendor support: Check warranty terms and the availability of customer support from the manufacturer or seller.
Selecting the best main breaker lockout kit depends on your specific panel brand and amperage rating, as well as how you plan to use a portable generator during outages. The options above are designed to deliver safe interlock operation, straightforward installation, and long-term durability for common 150-200 amp residential panels.