How does a generator interlock kit work on my panel?

A generator interlock kit is a mechanical safety device that prevents your main breaker and generator breaker from being ON simultaneously, eliminating the deadly risk of backfeeding power into NB Power lines. This is a critical safety requirement in New Brunswick and prevents electrocution of utility workers during power outages.

The interlock kit consists of a metal plate that slides over your electrical panel's breakers. When installed by a licensed electrician, it creates a physical barrier that allows only one breaker to be in the ON position at a time - either your main utility breaker OR your generator breaker, but never both. The plate has slots that align with the breaker handles, and when you slide it to turn on the generator breaker, it physically blocks the main breaker from being turned on.

How it works during a power outage: When NB Power goes out (common during our Maritime ice storms), you first turn OFF your main breaker, then slide the interlock plate to allow the generator breaker to be turned ON. This feeds power from your portable generator through a transfer switch or inlet box into selected circuits in your home. When utility power returns, you reverse the process - turn OFF the generator breaker, slide the plate back, then turn ON the main breaker.

TSANB requirements in New Brunswick mandate that generator connections must have proper transfer equipment to prevent backfeeding. An interlock kit satisfies this requirement for portable generators and costs significantly less than an automatic transfer switch. The installation requires an electrical permit from TSANB and must be done by a licensed electrician. You'll also need a generator inlet box installed on your home's exterior.

Important safety considerations: Never attempt to install an interlock kit yourself - improper installation can kill utility workers and cause fires. The kit must be specifically designed for your panel model (Square D, Siemens, etc.). Your electrician will also need to install a generator inlet box with appropriate amperage rating for your generator size. Most homeowners choose 30-amp or 50-amp inlets depending on their generator capacity.

The typical cost for interlock kit installation in New Brunswick ranges from $800 to $1,500, including the kit, inlet box, and electrical permit. This is much more affordable than a whole-home automatic transfer switch ($3,000-$8,000) while providing the same safety protection. Given New Brunswick's frequent ice storms and power outages, many homeowners find this a worthwhile investment for backup power capability.

Need help finding an electrician for generator interlock installation? New Brunswick Electrical can match you with licensed professionals who specialize in backup power systems and understand TSANB requirements.