Product FAQs

Product FAQ

What is a Generator Interlock Kit?

The Interlock Kit is a device that creates a mechanical interference between the main breaker and a generator back feed breaker. This interference prevents both breakers from being turned ON at the same time. By “Interlocking" these breakers you will have protected the public power system by insuring that your generator does not accidentally put power on the utility grid while it is running.

Using our Kit improves the safety of your home or business while running a generator. No need to run multiple extension cords for different outlets. With the Interlock Kit, you can simply plug one end of a generator power cord into your generator and the other end into a generator convenience inlet box or receptacle plug. Ditch expensive automatic switches that limit your accessibility and instead run everything using the ORIGINAL Interlock Kit. Depending on the capacity of the generator you may be able to run all of the circuits in your home. 

Interlock Kits are intended to be installed by qualified electricians. We use MET Laboratories, one of America's most trusted labs, to test our Interlock Kits to UL 67 and National Electrical Code standards.

What does an Interlock Kit look like?


The image  above shows an example of what an Interlock Kit looks like on a panel. We stock over 50 different Kits so yours may look different – but the concept is the same. When the Kit installation is complete, it becomes a permanent part of the front cover to the panel.

What do I get in my Interlock Kit?

  • Front Plate (slide)
  • Back Plate (base)
  • Binder posts
  • Binder screws
  • 11/64 drill bit
  • Military grade Loctite
  • Instruction booklet
  • Main breaker label sticker
  • Generator breaker label sticker
  • Danger label sticker
  • “Instructions for Use" label sticker
  • Breaker retainer & self tapping screws
  • Retaining strap
  • Retaining strap label
Items sold separately from the Interlock Kit:
  • Convenience inlet boxes or receptacle plugs
  • Generator power cords
  • Back-feed & tandem breakers
  • Power-back meters

How do I choose the correct Kit?

Care must be taken when selecting the correct Interlock Kit! We use the following ways to match Interlock Kits:

  • First determine who the manufacturer is
  • Next, note where the main breaker is located in the panel. Is it centered? Is it offset to the right or left from the center of the panel? is the main breaker attached to the branch circuits? Is it located above the branch circuits? How many amps is the main breaker?
  • If you have a gap between the main breaker and branch circuits, please measure the gap. Starting from the bottom of the main breaker measure down to the top of the branch circuits. (inches)
  • Finally determine the throw direction of the main breaker. Is the main throwing; horizontally (left to right) or vertically (up and down)?
After reading the following, go to the “Interlock Kit Selection List" on our website. If you do not see the selection list, click the drop down menu located in the top left corner of your screen. This menu will list the manufacturers that each kit is compatible with. Once you select your manufacturer, you will see multiple panel pictures displayed. Using the steps above select the Interlock Kit that most closely matches your own panels description. If you would like confirmation from one of our Interlock Kit experts, simply submit a photo of your electrical panel to: questions@interlockkit.com or call (804)726-2448

How does the Interlock Kit work?

A power panel is a distribution and protection system for electricity in your home. Power is fed from the utility into your panel. From here it runs across the different circuit breakers and then out to the rest of your home. Our product, the Original Interlock Kit, will allow only allow ONE of these power systems to be operational inside of the panel at any given time. This prevents dangerous back-feeding scenarios.

When transferring from one power source to the other follow these steps:

  • Turn the MAIN breaker to the “OFF" position
  • Turn the BRANCH circuits to the “OFF" position as well
  • Slide the Interlock Kit: up, down, left, or right at this point to block the main breaker into the “OFF" position
  • Connect and start your generator
  • Turn the GENERATOR breaker to the “ON" position
  • Turn on your essential circuits one at a time!

*Warning: Allow your appliances to start to before engaging the next circuit breaker*

To transfer back to the main power grid, reverse these steps beginning by turning the GENERATOR breaker to the “OFF" position.

Note: Large loads such as water heaters, microwaves, dryers etc. may not all be able to run at the same time. Remember breakers themselves do not use power unless something in the room that they feed has been turned ON. For this reason, you could turn on all of your light controlled breakers, as you move throughout the house, you can them on lights as you go, but do not forget to turn off devices that are not currently in use. If you have electric heat or central air most generators under 10,000 watts will not have enough capacity to run these items. Interlock Kits are compatible with any size generator, we recommend something as large as 12,000 or 15,000 watts to run your AC unit. This does not apply to gas, oil, or propane heated homes.

Do Interlock Kits and optional parts carry a warranty?

All products listed and sold by Generator Interlock Technologies, LLC are covered by a satisfaction guarantee for 30 days or you will be refunded for the full amount of the products ordered, shipping charges not included in refund. After 30 days all sales are final. To receive full refund the product or products ordered must be returned and must be without altercation or damage not considered normal wear and tear as a result of use or installation. Any questions can be directed to Generator Interlock Technologies by using the contact information setup on this site.

What I can run with my generator?

Typical appliance wattage

  • Electric water heater – 4500 watts
  • Microwave – 1600 watts
  • Toaster oven – 1800 watts
  • Stove top element (one) – 2200 watts
  • Hair dryer – 1500 watts
  • Well pump – 2000 watts
  • Basement sump pump – 900 watts
  • Refrigerator – 700 watts
  • Freezer – 700 watts
  • Furnace or boiler – 700 watts

Even with only a 6000-watt generator, you can do almost anything in your home that you would normally do – just not all at once. (depending on the capacity of your generator)

Most appliances have the wattage clearly listed, in the event that it is not; if only amperes and volts are given, just multiply them together to get watts. (10.2 amps x 120 volts = 1224 watts)

How do I connect my generator breaker to my generator?

A licensed electrician would use non-metallic wire (Nm wire commonly referred to as ROMEX) and hard wire your generator breaker to your convenience inlet box or receptacle.

After moving your Interlock Kit to block the main breaker, you would simply have to plug in one end of a generator power cord into the generator and the other end into the inlet box receptacle.

How do I use the generator to feed my panel?

Back Feed Breakers (generator breaker)

Your breaker needs to match the manufacturer of the panel that you are installing the Interlock Kit into. Look for a 2-pole 30 or 50 amp breaker for your generator breaker.

Generally people use a 30 amp breaker, inlet box, and power cord for generators less than 10,000 running watts and 50 amp setup for larger units. For generators with outlets greater than 50 amps, please consult the factory.

*See photo below for an example of a two-pole back-feed breaker*

How do I free up spaces for my Back Feed Breaker?

Piggyback or Tandem Breakers

These breakers allow you to create space. most breakers have a single toggle switch. In the case of the tandem breaker two independent toggle switches will be consolidated into a single breaker space. This allows you to create an open space by combining two breakers into one space.

*See photo below*