Choose a breaker interlock if your panel’s maker sells one for your exact panel and you want the freedom to power any circuit in it. Choose a manual transfer switch such as the Generac 6382 if you want a separate, purpose-built switch with its own generator inlet. Either way a licensed electrician fits it, and in most places the work needs a permit or a notice to your utility, sometimes before you buy: see rules by province and state.
Once a portable generator is in the garage, the next question in every outage thread is how to get its power into the house without a dozen extension cords. The safe answers all do one job: they make it physically impossible for the generator and the utility to feed your wiring at the same time. Interlocks and transfer switches do that in different ways, and the rules about which one you may use depend on where you live. Both kinds sit in our transfer switches and surge protection section.
Safety: never connect a generator to your house through a wall outlet, a male-to-male “double plug” cord or a direct wire into the panel. That backfeeds the grid, which can kill line workers, damage equipment and start fires. Until a switch or interlock is installed, run appliances on heavy-duty, outdoor-rated extension cords plugged straight into the generator, as Canada’s Get Prepared guidance advises.
The power outages page lists electricians in Montréal, Québec City, Ottawa and Vancouver who fit inlets, interlocks and transfer switches.
Interlock and transfer switch side by side
| Breaker interlock | Manual transfer switch (e.g. Generac 6382) | |
|---|---|---|
| What it is | A plate or slide on your existing panel that stops the main breaker and a generator breaker being on together | A separate switch box that moves the house from utility to generator |
| Circuits you can run | Any breaker in the panel | The whole panel with the 6382; smaller switches cover a few chosen circuits |
| Generator inlet | Bought and fitted separately | Built into the 6382’s enclosure (L14-30) |
| Certification | Use the panel maker’s own interlock for that panel; some utilities accept no other kind | Look for certification to CSA C22.2 No. 178.1 or UL 1008 |
| Who installs it | Licensed electrician | Licensed electrician |
| Cost | Usually the cheaper route, owners report | More hardware, often more labour |
How each one works
An interlock is a mechanical accessory screwed to the front of your breaker panel. It lets you switch on a breaker fed by the generator inlet only after the main breaker is off, so the two sources can never meet. Your panel carries on doing its job; you pick circuits by flipping its breakers. A manual transfer switch is a separate box between the utility and your wiring. The Generac 6382 is rated for the service entrance: a 200 A utility side and a 30 A generator side, 125/250 V, in an outdoor NEMA 3R aluminium enclosure, with room for up to 12 extra branch circuits. On this criterion neither wins; they reach the same result by different routes.
Rules by province and state
Everywhere, a generator reaches your wiring only through a transfer switch or interlock fitted by a licensed electrician. Who must be told first, and which devices are accepted, depends on your province or state. This is what the official documents said when we read them in November 2026; check them again before you buy.
Québec: a permanent backup system (a standby generator, or a generator or battery that feeds the panel) is installed by a master electrician who is a member of the CMEQ, with a compliant transfer switch, and the electrician checks that the home is fully cut off from the grid during an outage (Hydro-Québec’s three key rules). The electrician sends Hydro-Québec a backup-connection request, with a single-line diagram and the equipment’s certificates, before the equipment is bought or installed. Hydro-Québec accepts a transfer switch certified to CSA C22.2 No. 178.1 or UL 1008, a certified double-throw safety switch (CSA C22.2 No. 4 or UL 98), or a keyed interlock only if it is the panel maker’s own accessory, not a universal plate. Generac’s 6382 page doesn’t state its certification, so ask your electrician to confirm it. Hydro-Québec’s request form (PDF).
Ontario: hardwiring a generator to a transfer switch always needs an ESA notification of work, even when a licensed electrical contractor does it. A transfer device that plugs into the meter base must be certified to ANSI/CAN/UL 1008M, and some utilities forbid it. ESA Bulletin 2-33-0 (PDF).
United States: hookups fall under the National Electrical Code as your state and city adopt it, and a portable generator may not backfeed a building’s permanent wiring. A permit application typically asks for a site plan, the generator and transfer-switch specs and a single-line diagram (one California city’s checklist (PDF)). Ask your building department about the permit and whether it accepts an interlock before you buy; owners report that interlock approval varies from place to place.
Other provinces and territories: we haven’t read their rules yet. Before you buy, ask a licensed electrician and your electricity utility who may do the work, whether a permit or a notice is needed, and which devices they accept.
Which circuits you can run
With an interlock, every breaker in the panel is available, which is why owners praise its flexibility: furnace today, well pump tomorrow, kitchen outlets for the coffee maker. The Generac 6382 switches the whole 200 A panel too, so it matches the interlock here. Smaller transfer switches that cover six or ten chosen circuits are a different story: you choose the circuits once, at installation. The catch with whole-panel access, from either device, is the same. Generac’s own advice is to switch off large loads at the panel during an outage so the generator isn’t overloaded. An 8,000 W portable will not run a whole house at once; for what yours can carry, see what size generator you need. Result: a tie, with whole-panel devices needing more care.
Which generators fit
Both routes need a generator with a 120/240 V outlet that can feed an inlet, usually a 30 A L14-30R twist-lock. Generac says the 6382 works with portables from about 5 kW that have a 30 A receptacle, and its generator cord plugs into an L14-30 inlet on the bottom of the enclosure; Generac sells matching cords. Its 50 A sibling, the 6335, takes bigger generators. An interlock needs the same kind of inlet box, bought separately and wired to a generator breaker in the panel. Generators whose largest outlet is a 120 V TT-30R, such as many 4,500 W inverters, can’t feed either one’s 240 V circuits. Neither device wins on fit; your generator’s outlet decides.
The generator we pair with these hookups is the Generac GP8000E COsense in its 49ST/CSA configuration (model G0077151): 8,000 running and 10,000 starting watts, an L14-30R, COsense carbon monoxide shutdown and, per Generac, a configuration for Canada.
Installation and who does it
This is not a weekend job for anyone but a licensed electrician, whichever device you choose. Both involve working inside the panel or at the service entrance, where parts stay live even with the main breaker off. Generac recommends a certified electrician for the 6382, and the switch’s two-year warranty is short for a permanent fixture. An interlock is usually less work because it uses the existing panel, plus an inlet box outside. Interlock wins on labour; neither is DIY.
Cost and parts
Owners who compare quotes usually find the interlock route cheaper: the kit, an inlet box, a generator breaker and a shorter job. A whole-panel transfer switch is more hardware and can mean more labour at the service entrance. Both need a proper generator cord of the right length; long cords cost more, so plan where the generator will sit, at least 6 m (20 ft) from the house. Prices move, so compare the parts in our transfer switch listings with your electrician’s quote. Interlock wins on cost, if your panel maker sells one.
Which should you choose?
Choose an interlock if…
- your panel’s maker sells an interlock for that exact panel
- you want any circuit available and the lower-cost route
- your local inspector or utility accepts it
Choose a transfer switch if…
- no maker’s interlock exists for your panel, or your inspector won’t accept one
- you want a separate switch with its own inlet, like the 6382’s L14-30
- your generator has a 30 A 120/240 V outlet and about 5 kW or more
Still choosing the generator itself? See the best generators for a power outage in Canada, every model in portable and inverter generators, or, if you would rather skip the wiring altogether, a power station versus a generator. Everything else is in backup power.
Interlock and transfer switch questions
What is the main difference between an interlock and a transfer switch?
An interlock is an accessory on your existing panel that stops the main breaker and a generator breaker being on together. A transfer switch is a separate device that moves your wiring from the utility to the generator. Both prevent backfeeding; which one you may use depends on your province, state and utility.
Can I install a transfer switch or interlock myself?
No. Both mean working inside the panel or at the service entrance, where parts stay live with the main breaker off, so hire a licensed electrician. In most places a permit or a notice to your utility comes first; see rules by province and state.
Can I plug my generator into a wall outlet if I turn off the main breaker?
No. Never plug a generator into a wall outlet or use a male-to-male cord. A main breaker left on, or switched back on, sends generator power into the street, where it can kill line workers. Use extension cords to appliances until a switch or interlock is installed.
Will the Generac 6382 work with my generator?
Generac says it suits portable generators from about 5 kW with a 30 A receptacle, connected by a cord to the L14-30 inlet on its enclosure. A generator whose largest outlet is a 120 V TT-30R won’t feed it; for bigger generators Generac makes a 50 A version, the 6335.