Answering the need for safe, code-compliant backup power, this guide highlights the best interlock kits for generators across 150 and 200 amp panels. These kits help prevent backfeeding and ensure power to essential circuits during outages. They’re best for homeowners who want a straightforward, installer-friendly solution and for renters or new homeowners seeking reliable emergency power without permanent transfer switches.
The following table summarizes five top options to help you compare at a glance. Focus is on compatibility, spacing between breakers, and clarity of installation requirements to guide a quick decision.
| Product | Spacing | Compatible Panels | Best For |
|---|---|---|---|
| Natupal Generator Interlock Kit (SD200A) | 1 3/8 inches | Square D QO / Homeline 150-200 A | Those needing precise 1 3/8″ spacing and a professional-grade fit |
| EXCELFU Eaton Cutler Hammer BR Series | 1 1/4 – 1 7/16 inches | BR 150/200 A, CH with neutral | New installs seeking reliable safety and broad compatibility |
| EXCELFU GE 150/200 Amp Panels | 1 1/4 inch | GE 150/200 A panels | GE owners wanting a straightforward, safe backfeed solution |
| SPZOCE GE 150/200 Amp Panels | 1 1/4 inch | GE 150/200 A panels (vertical main) | Simple installation with clear spare spacing guidance |
| QYZZRS Square D QO/Homeline 150/200 A | 1 3/8 inches | Square D QO / Homeline 150-200 A | Best for precise spacing and quick setup with Square D panels |
Natupal Interlock Kit for Square D Panels
Compatibility: Square D QO or Homeline panels, 150 or 200 amp. Spacing: 1 3/8 inches between main and generator breakers. This kit is designed to safely direct generator power to any circuit while keeping mains and generator from energizing simultaneously. Best for homeowners with QO or Homeline panels who want a professionally designed interlock solution. Limitations: installation requires precise alignment; verify panel model and breaker layout before purchase.
EXCELFU Eaton Cutler Hammer BR Series Interlock Kit
Compatibility: Eaton/Cutler Hammer BR and CH series, 150-200 A. Spacing: 1 1/4″ to 1 7/16″ between main and branch breakers. This kit offers a safe, cost-effective backfeed method for a broad range of Eaton panels. Best for homes with Eaton BR or CH panels seeking a robust interlock solution. Limitation: double-check neutral configuration if CH panels are involved.
EXCELFU GE 150/200 Amp Interlock Kit
Compatibility: General Electric GE 150/200 A panels. Spacing: 1 1/4″ between main and branch breakers. Benefits include a reliable method to backfeed with a portable generator while ensuring all household appliances stay powered safely. Best for GE panel owners who want a dedicated interlock setup. Caution: ensure your GE panel model matches the interlock kit specifications before purchase.
SPZOCE Generator Interlock Kit for GE Panels
Compatibility: GE 150/200 A panels (115/vertical main spacing). Spacing: 1 1/4″ between main and branch breakers. This kit emphasizes easy installation with included drill bit and manual. Best for GE users seeking straightforward setup with clear installation guidance. Limitation: ensure correct spacing on your specific GE panel model to avoid misalignment.
QYZZRS Square D QO/Homeline Interlock Kit
Compatibility: Square D QO or Homeline 150/200 A panels. Spacing: 1 3/8 inches between main and generator breaker. Features an installation note emphasizing correct screw placement and alignment. Best for users who want a precise, ready-to-install kit for QO/Homeline panels. Limitation: incorrect alignment can prevent proper operation; follow the installation bulletin exactly.
Flngr Interlock Kit for GE Vertical Main Panels
Compatibility: GE vertical 150/200 A panels. Spacing: 2 1/4 inches between main and branch breakers. This kit provides a larger spacing option for certain GE configurations. Best for GE vertical mains that require more clearance. Caution: verify 2 1/4″ spacing matches your panel and breaker layout before ordering.
Buying Guide: What to Consider When Choosing a Generator Interlock Kit
What panel type do you own? Interlock kits are panel-specific. Check if your panel is Square D QO/Homeline, GE, or Eaton/Cutler Hammer BR/CH, and confirm the exact amp rating (100, 125, 150, or 200 A).
What spacing is required between main and generator breakers? Common spacings include 1/4″, 3/4″, 1 1/4″, 1 3/8″, and 2 1/4″. Matching the correct spacing is essential for safe operation and code compliance.
How easy is installation? Look for kits that include necessary hardware, installation manuals, and even drill bits. Some options provide step-by-step guidance to minimize misalignment risks.
What safety features are included? A good interlock kit prevents backfeeding and ensures the main and generator cannot energize simultaneously. Confirm the kit integrates with your specific panel to minimize electrical risk.
Are there limitations or compatibility notes? Some kits require neutral configuration or have specific orientation constraints (horizontal vs. vertical main). Double-check these details to avoid installation problems.
Frequently Asked Questions
- What is a generator interlock kit? – It safely connects a portable generator to a home panel by preventing backfeed and ensuring only one power source is active at a time.
- Do interlock kits require a transfer switch? – No. Interlock kits provide an alternative method to backfeed safely without a full transfer switch.
- Which panels are most common for these kits? – Square D QO/Homeline, GE, and Eaton/Cutler Hammer BR/CH series are among the most common.
- Is installation difficult for a DIYer? – Some kits are straightforward with included hardware, but verify panel compatibility and consider professional installation if unsure.
- Can I mix brands? – It’s best to use a kit designed for your specific panel brand and model to ensure proper operation and safety.
- What spacing should I expect for 150/200 A panels? – Spacing typically ranges from 1 1/4″ to 1 3/8″ or 2 1/4″ depending on the model; confirm with the manufacturer’s guidelines.