Best Generator Interlock Kit for Safe Backup Power
When preparing for power outages, a generator interlock kit provides a code-compliant, safe method to backfeed essential circuits. This article highlights five top interlock kits compatible with common panels from Square D, Eaton/Cutler Hammer, General Electric, and more. Each option enables a secure generator connection while keeping your home’s appliances protected and accessible. The table below compares the featured products to help you choose quickly.
| Product | Brand | Panel Compatibility | Spacing (Main to Generator) |
|---|---|---|---|
| Natupal Generator Interlock Kit (SD200A) | Natupal | Square D QO or Homeline 150/200 A | 1 3/8 inches |
| EXCELFU Generator Interlock Kit (BR Series) | EXCELFU | Eaton/Cutler Hammer BR/CH 150/200 A | 1 1/4 – 1 7/16 inches |
| QYZZRS Interlock Kit (Square D QO / Homeline)** | QYZZRS | Square D QO or Homeline 150/200 A | 1 3/8 inches |
| WHXMHRQ Interlock Kit (Square D QO / Homeline) | WHXMHRQ | Square D QO or Homeline 150/200 A | 1 3/8 inches |
| SPZOCE Interlock Kit (BR Series / GE Panels) | SPZOCE | Eaton/Cutler Hammer BR & CH; GE 150/200 A | 1 1/4 – 1 7/16 inches |
Natupal Generator Interlock Kit for Square D QO or Homeline
Compatible Models: Generator Interlock Kit designed for Square D QO or Homeline panels, 150- and 200-amp configurations. Spacing: 1 3/8 inches between the main and generator breaker. This safety interlock directs generator power safely, enabling reliable operation of home appliances during outages and minimizing backfeed risks.
EXCELFU Generator Interlock Kit for BR Series
Compatible Models: Eaton/Cutler Hammer BR Series and CH Series 150/200 amp panels. Spacing: 1 1/4″ to 1 7/16″ between main and branch breakers. This kit emphasizes safe backfeeding and maintains operation of essential appliances during power outages with a straightforward installation process and included drill bit.
QYZZRS Interlock Kit for Square D QO / Homeline
Compatible Models: Square D QO and Homeline 150/200 amp panels. Spacing: 1 3/8 inches between main and generator breaker. Includes installation guidance emphasizing screw attachment before alignment to ensure precise positioning and proper interlock operation for safe power transfer during outages.
QYZZRS Interlock Kit for Eaton Cutler Hammer BR/CH
Compatible Models: Eaton Cutler Hammer BR/CH series, 150/200 amp. Spacing: 1 1/4″–1 7/16″ between main and generator breakers. Comes with drill bit and screws to facilitate alignment, aiming to reduce installation errors and improve reliability of generator backfeed.
WHXMHRQ Interlock Kit for Square D QO / Homeline
Compatible Models: Square D QO and Homeline 150/200 amp panels. Spacing: 1 3/8 inches. Features include a steel interlock plate and a 3/16-inch drill bit, with installation notes to align the kit accurately and ensure safe generator backfeeding and uninterrupted appliance use during outages.
SPZOCE Interlock Kit for BR/GE Panels
Compatible Models: GE 150/200 amp panels and Eaton BR/CH BR series, with 1 1/4″–1 7/16″ spacing between main and branch breakers. Installation includes a drill bit and clear guidance, designed to safely backfeed a generator while preserving access to household appliances during outages.
Buying Guide: Key Purchase Considerations
- Panel Compatibility: Confirm your panel brand and model (Square D QO/Homeline, Eaton BR/CH, GE) before selecting a kit. Incompatible kits can fail to fit or function safely.
- Spacing Requirements: Most interlock kits specify a specific distance between the main breaker and generator/branch breakers. Match the spacing to your panel’s needs to ensure reliable operation and compliance with electrical codes.
- Installation Effort: Some kits come with drill bits and screw packs; others require more precise alignment steps. Consider your DIY comfort level and whether professional installation is preferable.
- Safety Features: Look for robust steel construction and clear installation instructions. A properly installed interlock minimizes backfeed risks and protects both the electrical system and generator operator.
- Documentation and Support: Kits with comprehensive manuals, starter labels, and included start-up procedures help reduce mistakes. Ensure you have access to updated guidance from the manufacturer.
- Economy vs. Convenience: Several kits offer similar compatibility across brands, but installation complexity and included accessories can vary. Weigh total value against your specific needs and space constraints.
- Warranty and Returns: Verify warranty terms and seller support in case of installation issues or component defects.