Best Interlock Switches for Generators: Safe and Easy Backup Power Solutions
When choosing a generator back-up setup, a reliable interlock kit is essential for safe, code-compliant operation. This article highlights five top interlock switches compatible with popular panel brands and models, focusing on spacing, compatibility, and installation notes. Each product helps prevent backfeeding and protects home loads during outages, while allowing convenient switching between utility power and generator power. Read on to compare options and find the best fit for your panel type and backup needs.
| Product | Brand | Spacing Between Breakers | Compatible Panels |
|---|---|---|---|
| Natupal Generator Interlock Kit | Natupal | 1 3/8 inches | Square D QO and Homeline 150/200 Amp |
| Generator Interlock Kit (QYZZRS) | QYZZRS | 1 3/8 inches | Square D QO and Homeline 150/200 Amp |
| Generator Interlock Kit (EXCELFU Eaton BR) | EXCELFU | 1 1/4 – 1 7/16 inches | Eaton Cutler Hammer BR 150/200 Amp |
| Siemens/Murray Interlock Kit (XMK) | XMK | 7/8 – 1 1/4 inches | Siemens/Murray 150/200 Amp |
| MOWABI Interlock Kit (Square D QO/Homeline) | MOWABI | 1 3/8 inches | Square D QO/Homeline 150/200 Amp |
Natupal Interlock Kit for 150/200 Amp Panels
Brand: Natupal
Compatibility: Square D QO or Homeline 150 or 200 amp panels. Provides 1 3/8 inch spacing between the main and generator breaker. Designed to safely direct generator power to circuits during outages, minimizing backfeed risk and protecting appliances.
QYZZRS Interlock Kit for QO/Homeline Panels
Brand: QYZZRS
Compatibility: Square D QO and Homeline 150/200 amp panels. Includes 1 3/8 inch spacing between main and generator breaker. Installation notes emphasize aligning before final positioning to ensure reliable operation and avoid installation errors.
EXCELFU Interlock Kit For BR Series
Brand: EXCELFU
Compatibility: Eaton/Cutler Hammer BR 150/200 Amp panels. Spacing ranges from 1 1/4 to 1 7/16 inches between main and branch breakers. Emphasizes safe backfeeding and protecting household appliances during outages, with guidance on confirming model and spacing prior to installation.
XMK Interlock Kit For Siemens/Murray Panels
Brand: XMK
Compatibility: Siemens or Murray 150/200 Amp panels. Spacing between main and branch breakers ranges from 7/8 to 1 1/4 inches. Designed to prevent simultaneous mains and generator power, safely directing generator power to circuits while maintaining appliance protection.
QYZZRS Eaton BR Series Interlock Kit
Brand: QYZZRS
Compatibility: Eaton Cutler Hammer BR and CH Series 150/200 Amp panels. 1 1/4 to 1 7/16 inch spacing between the main and generator breaker. Installation notes highlight verifying model and spacing, and drilling alignment to ensure proper fit and reliable operation.
MOWABI Interlock Kit For Square D QO/Homeline
Brand: MOWABI
Compatibility: Square D QO or Homeline 150/200 Amp panels. 1 3/8 inch spacing between main and generator breaker. Notes emphasize premium materials and easy installation with the included drill bit and guidelines to ensure correct model fit for safe operation.
Buying Guide
Key considerations when selecting a generator interlock kit include panel compatibility, spacing between main and generator breakers, and ease of installation. Confirm that the kit matches your breaker panel brand and amperage (150 or 200 Amp are common). Spacing must align with your panel’s design to ensure a secure fit and proper safe backfeeding. Look for kits that clearly state safe operation to prevent simultaneous mains and generator power, reducing the risk of backfeed to the grid or appliances. Installation ease matters: included hardware, drill bits, alignment guides, and clear instructions can save time and reduce errors.
Safety and reliability are paramount. Some products emphasize additional protections for appliances and sensitive electronics, while others highlight compatibility with multiple lines (QO, Homeline, BR, CH, Siemens/Murray). Evaluate your home’s load profile and standby power goals to choose a kit that supports essential circuits during outages. Warranty terms, customer support, and user reviews can provide practical insights into long-term performance. Finally, installation should comply with local electrical codes; consider professional installation if you’re unsure about breaker panel modifications.