The 2021 winter storm left a lot of DFW homes without power for days — some for nearly a week — and the conversation about backup power hasn't really cooled down since. A portable generator is the most common first step, but plugging one in the wrong way is dangerous, and a licensed install with the right safety hardware is what separates a smart backup system from a potential hazard. Here's how the inlet box and interlock kit work together to keep your family safe.
The inlet box is a weatherproof receptacle mounted on the outside of your home, where you plug in the generator cable. The cable runs into the house and connects to a special transfer switch mounted inside. The interlock kit is a mechanical device installed between your panel's breakers and the transfer switch — it physically prevents both the utility feed and the generator from being connected at the same time. That's not a suggestion; it's a mechanical lock that makes it physically impossible to backfeed power into the grid while a lineman is working on a line.
Backfeeding happens when you plug a generator directly into an inlet box or a dryer outlet without an interlock or transfer switch. Power flows backward through your home's wiring and onto the utility lines — which means a lineman repairing a downed line during a storm could be killed. The interlock kit is the reason this system is safe: it's a physical barrier that only allows one power source at a time. It also requires a proper permit and licensed installation in virtually every DFW city.
A typical 7,000 to 9,000-watt portable generator can keep the essentials running during a prolonged outage — a refrigerator, a freezer, some lighting, a ceiling fan or two, and maybe a well pump. It won't run central AC (most central AC units need far more than the generator can produce), and you'll need to cycle what's plugged in to avoid overloading. It's not a whole-home solution, but it's a reliable safety net for the critical loads during a snow belt or storm outage.
A whole-home standby generator (like a Generac or Kohler) is permanently installed on a concrete pad, fueled by propane or natural gas, and turns on automatically within seconds of an outage. It's the most convenient solution and can power an entire house. But it costs significantly more to buy, install, and maintain. The inlet + interlock approach is the far more affordable entry point and still provides critical backup for the loads that matter most. Grizzly installs both systems — generator inlet and interlock installation is our specialty.
An install typically takes half a day to a full day, depending on the panel brand and your home's layout. Grizzly will install the interlock kit specific to your panel brand (Federal Pacific, Square D, Siemens, and others all have different kits), mount the inlet box on an exterior wall, run the conduit from the inlet to the panel, install the transfer switch inside, and test everything. A permit is required, and we handle that too.
Want to get started? Text photos of your panel and the exterior of your home to (469) 896-3862 for a free same-day quote — Grizzly can usually schedule a site visit the same day you text. Senior and veteran discounts available. For emergencies, call (469) 863-9804.
Grizzly Electrical Solutions serves Rowlett, Garland, Plano, Richardson, and the greater Dallas–Fort Worth area. Get a quote or call for 24/7 emergency service.