An inlet and interlock let you run part of your house from a portable generator through your existing panel and existing wiring. The inlet box is a weatherproof connection point mounted outside. The interlock is a mechanical plate on the panel that makes it physically impossible to have the utility main and the generator breaker closed at the same time. Between them, they replace the cord run through a cracked window, and they do it in a way an inspector will pass.
This page covers portable units. If the picture in your head is a permanent machine outside that starts by itself with nobody home, you want whole-house standby generator installation instead — we carry those out complete, and choosing between the two is worth five minutes on the phone before you buy anything.
Storm outages are a fact of life across Middle Tennessee — the same lines that serve Nashville, Hendersonville, Gallatin and White House run through a lot of mature tree canopy, and a summer system that clips Sumner or Robertson County can leave a neighborhood dark for a day or more. We install inlets and interlocks for homeowners across our Middle Tennessee service area, and the whole job is usually one visit.
What an inlet and interlock installation covers
The load conversation, the outside inlet box, the feeder, a kit matched to your panel, and a labeled sequence.
- A load conversation first. How much generator you have, and what you actually want running: refrigeration, a well pump, the furnace blower, some lighting and outlets, or more. This determines everything that follows, and it is worth being honest about — a generator sized for a fridge will not run central air, and no amount of wiring changes that.
- A generator inlet box mounted outside in a sensible location: reachable from where the generator will actually sit, far enough from windows and doors, and clear of where you park.
- A dedicated feeder from the inlet to the panel, in the right conductor size for the inlet rating and the run length.
- A panel interlock kit matched to your specific panel make and model. This is the part that matters most and the part most often done wrong. A kit is listed for particular panels; fitting a generic plate to a panel it was not made for is not a code-compliant installation, and if your panel has no listed kit available, we will tell you rather than improvise one.
- A backfed generator breaker, properly secured, with the interlock installed so the sequence is enforced mechanically rather than by memory.
- Permit and inspection coordination where the local authority requires it.
- A labeled panel and a walkthrough, so that in an actual outage — at night, in the rain — the sequence is written on the cover and not something you are trying to recall.
When this is the right solution for you
Fits a portable unit you already own, repeat outages, loads that cannot sit dark, or panel work already planned.
- You want a permanent way to use a portable generator without replacing the whole backup-power setup. An inlet and interlock use the portable unit you already own and remove the extension-cord workaround.
- You already own a portable generator and have been running cords from it.
- You have lost power more than once and have decided you are done improvising.
- You have something in the house that cannot lose power for long — a well pump, a sump pump, a freezer, medical equipment, or a home office you cannot be offline from.
- You are having other panel work done. If a panel upgrade is already on the cards, adding the interlock at the same time saves a second mobilization.
How we do the work
Panel and kit compatibility checked first, then inlet location, feeder, interlock and breaker, permit where required, and the sequence walked with you.
We start at the panel, because the panel decides what is possible. We identify the make and model, confirm a listed interlock kit exists for it, and check there is space in the right position for the generator breaker — interlocks require the breaker in a specific slot, and a full panel or an obsolete one changes the plan. If it does change the plan, you hear that at the assessment, not after the work is under way.
That panel check is a compatibility check for the interlock, not automatically a recommendation to replace the panel. If the assessment raises a separate panel condition issue, we will tell you that as its own conversation.
We then agree the inlet location with you on site, run and terminate the feeder, fit the interlock and breaker, and label everything. Where a permit is required we handle the paperwork and meet the inspector.
Last, we walk the sequence with you: what to shut off, what order to close breakers in, how to shed load if the generator complains, and what never to do — starting with never backfeeding through a dryer outlet, which is the practice this installation exists to make unnecessary.
Why bring Power Line Electrical Contractors in for this
Licensed, bonded and insured work under Tennessee Electrical Contractor #82227, inspected where the jurisdiction requires it.
Backfeeding a panel is one of the few pieces of residential electrical work that can kill someone who is nowhere near your house. A generator connected without an interlock can energize the utility line a crew is working on. That is why this job is worth doing properly and worth having done by someone licensed for it.
The work is performed under Tennessee Electrical Contractor #82227 by a licensed, bonded and insured contractor, and it is inspected where the jurisdiction requires. Our hours are 5:00 AM to 7:00 PM every day of the week, and emergency and same-day service is available. Estimates cost nothing, and if the job grows into panel work you can ask about financing at the time we price it.
Request an estimate or look through our full range of electrical services.
Generator Inlet and Interlock FAQs
Is a generator interlock kit compatible with any electrical panel?Why the kit has to be listed for your panel make and model, not adapted to it.
No. A panel interlock kit must be listed for your specific panel make and model — fitting a generic plate to an unlisted panel isn't code-compliant, and if no listed kit exists for your panel, we'll tell you rather than improvise one.
Can I backfeed my generator through a dryer outlet instead of installing an interlock?Why backfeeding through an outlet endangers line crews and what replaces it.
No — that practice can energize utility lines and endanger crews working on them. A code-compliant inlet and interlock installation is what makes that unnecessary and safe.
Is a permit required for a generator inlet and interlock installation?How permit and inspection coordination fits into an inlet and interlock job.
Permit and inspection coordination is handled where the local authority requires it, and it's part of how we install every inlet and interlock system.
When does a portable-generator setup turn into panel work?The conditions that make panel work a separate decision rather than part of this one.
Only when the panel can't take the installation as it stands. That means no listed interlock kit for your make and model, no free breaker position where the interlock requires one, or a capacity or safety condition the assessment turns up in its own right. None of those turns an inlet job into panel work automatically — you hear it at the assessment, and panel work stays a separate decision rather than something folded into the generator job.
Do you offer emergency electrical services?How urgent calls are handled outside a planned backup-power installation.
If you have an electrical emergency in the Nashville area, please call (270) 991-9827 immediately for the fastest response. While we are not a dedicated 24/7 emergency-only company, Power Line Electrical Contractors prioritizes urgent safety issues and critical power failures for our clients. We strive to provide same-day or prompt assistance for dangerous situations like sparking panels, sudden power loss, or storm damage in Hendersonville, Franklin, and Gallatin. For your safety, do not attempt to fix emergency electrical issues yourself—contact our licensed team to discuss your situation and get professional guidance.
