The Generator Interlock Kit, also known simply as an interlock kit, is an inexpensive, easy-to-use alternative to a manual transfer switch. But if you don't know what interlock kits or manual transfer switches are, don't worry. We explain everything to you in this article.
First of all, imagine you are sitting at home enjoying a delicious dinner or watching TV. Suddenly your energy is gone. What's your solution? you have a solution, right?
Hopefully you've thought of a plan that involves some sort of generator. If you use a permanent standby generator, the backup power supply is activated as soon as the conventional grid power fails. However, this is not the case with a portable generator.
You must connect your portable generator directly to your household electrical appliances or circuit. Be sure to locate the generator at least 5 feet away from windows, doors, or vents to avoid carbon monoxide poisoning.
There are several hazards to be aware of when hooking up your portable generator. An interlock kit is designed to protect against these dangers.
But before we talk about the interlock kit, let's address its alternatives and some of the challenges that come with them.
Before the generator interlock kit, there was...
extension cable
One option when using your portable generator is to connect it directly to appliances using extension cords. Aside from being a potential fire problem, extension cords snaking around your home can cause you or a family member to trip and fall. In addition, there are certain machines, such as the oven and kettle, that cannot be connected with a cable. With this plan, you cannot use these items until traditional energy is restored.
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An even more dangerous option, which is illegal in some places, is to plug your portable generator directly into the electrical service panel. This is where the circuit breakers are stored.
When your portable generator powers your home, it does so through a process calledReturn message. This is because the generator feeds electricity back into your home. This can cause equipment to burn out and damage your generator, but there is also a greater risk.
If your main switch is on while your portable generator is feeding back your system, you are endangering the lives of utility workers. Because if you leave the main switch on, the regenerated power from your generator can pump thousands of electrical volts into your neighborhood's power lines. Workers attempting to restore power could suffer fatal shock.
This could happen because you forgot to turn off the main switch. Or it could happen if someone else in the house turns it back on before turning off the power to the generator.
a transfer switch
A toggle is a safe option before the interlock kit. It is a separate set of circuit breakers that allow you to isolate specific circuits from the traditional power grid. With the flick of a single switch, you can power circuits with power from your generator.
This is easy and safe, but also expensive. Buying a switch and installing it can cost as much as $1,200.
Luckily, there's a less expensive option that's just as safe.
a transfer switch
A solution that ensures that the main switch and the generator switch cannot be on at the same time is important. The transfer desk, for example, is so important that it saves lives.
But does this solution have to cost $1,200?
Douglas Albertson, managing partner at Generator InterLock Technologies in Richmond, Virginia, didn't think so. In 2003 he realized the need for the generator interlock kit. In September of that year, Hurricane Isabel swept through Virginia and North Carolina, leaving 6 million people without power, many for weeks.
Suddenly there was an influx of people using generators for the first time. This high demand also resulted in a long wait for professional electricians to install safety devices such as a transfer switch.
The result was that many people unsafely connected portable generators to their homes. As we mentioned earlier, some had extension cords all over their homes. Others used what was dubbed the "Suicide Cable Generator".
Albertson felt there needed to be an easier and safer way for the public to connect their portable generator to their existing electrical system. I wanted this to be a viable option for everyone. This included those on a budget and consumers without room for a large standby generator or bulky transfer switch.
In 2005 he officially introduced his interlock kit to the world.
What is a generator interlock kit?
An interlock kit is a cheaper alternative to transfer switches. And instead of installing a separate circuit breaker in the form of a toggle switch, an interlock kit mounts to your existing panel.

The kit is easy. It acts as a manual version of the transfer switch, ensuring that the main and generator switches cannot be on at the same time. The interlock kit isolates these two systems. In one position, current cannot flow from the generator to the supply lines. In the other position, power from the supply line cannot harm your generator. Only one can be activated at a time.
And the interlock kit achieves this at a much lower price point than the transfer switch. A kit usually costs between $50 and $150.
How does a generator interlock kit work?
Interlock kits are custom designed for the specific service panel to which they are fitted. You should make sure you buy one that is compatible with your switch box.
However, once you've bought and installed the right kit, they all work the same.
First you need to turn off your main switch as well as the rest of your switches. Next you go to your garden. Connect the generator power cable to your generator and to the generator power entry box. Start your generator.
Back at your service panel you will need to slide your interlock kit up. This will reveal the circuit breaker for your generator that was previously included in the kit. If you slide it up, it will now lock your master switch. The interlock kit ensures that only one of the main or generator switches can be switched on at a time.
Turn on the circuit breaker for your generator. Now your home is ready to get power from your generator instead of the utility.
Flip each of your individual switches that you require to the on position. The only switch that should be left off is the main switch, which is still locked out by the kit. Your generator now powers the appliances and outlets you need.
When the traditional power grid is restored, you can turn off individual circuit breakers. This includes the circuit breaker on your generator. You will then slide your interlock kit down. This will expose the main switch and cover the generator off switch.
Turn on your main switch and then turn your individual switches back on. Your home is now being supplied from the public power grid again.
Unplug your generator and put your portable generator back in its storage location the next time you need it.
Advantages of a generator interlock kit
There's a lot to love about using an interlock kit. These are some of those benefits:
- An interlock kit eliminates the maze of extension cords you need when connecting your generator directly to appliances. Also, moving large appliances like a refrigerator to plug into an extension cord can be a daunting task.
- The kit does not require a separate breaker panel. It is installed in the main switch panel. This means cost savings and no additional wall space required.
- When your portable generator is connected to devices, it only consumes the amount of energy required by those specific devices. This is often much less than its capacity. Interlock kits and transfer switches allow the generator to use its full load capacity and provide more power to your home.
- The cost of an interlock kit is much less than a transfer switch.
- Installing a transfer switch or generator sub-panel can take an electrician up to eight hours due to the rewiring involved. An interlock kit, on the other hand, can be installed in under two hours. All that is required is to mount the correct kit on the front of the panel and wire a generator power input to your generator circuit breaker.
Disadvantages of a generator interlock kit
No solution is infallible. Interlock kits also have disadvantages. Here are some of the most notable:
- Underwriter Laboratories (UL) is a long-standing independent certification company. Your standards are very much respected. Many types of interlock kits are tested to UL standards by independent laboratories, but do not bear the UL listing mark. As a result, some inspectors will not allow its use.
- As mentioned, the kits install in the lid of your panel. While the cover is on, the interlock kit prevents the main and generator switches from being in the on position at the same time. However, if the cover is removed, both switches could be turned on. This error is very dangerous for utility workers.
- An interlock kit saves wall space by eliminating the need for an additional panel full of circuit breakers. However, the kit takes up space on your existing tumbler platter. You have to reserve two or three places for this.
- Some latch kits require drilling into the panel cover. Once installed, they cannot be removed without causing additional problems to your panel.
- When mains power is restored, a standby generator will automatically shut down. The conventional power grid takes over the power supply for your house. With appliances plugged directly into your portable generator, everything else in your house will turn on when the utility is fixed. However, with an interlock kit, you must turn off the main switch. This makes it difficult to know when the utility will reset.
Determine if an interlock kit is right for you
If your backup power strategy includes a portable generator, a generator lockout kit may be right for you.
And if you are interested in an interlock kit, it should be installed by a certified professional. Our staff can help you find experts in your area to help make your backup power plan a reality.
FAQs
How do I know what interlock kit I need? ›
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.
Do generator interlock kits meet code? ›Many jurisdictions require that interlock kits be installed to match local building codes. Consult with your local government to see what local regulations are regarding generator feeding. Your local jurisdiction may require that a professional electrician install the kit.
Which interlock device is the best? ›While there are plenty of ignition interlock devices available across the United States, we have determined that the best ignition interlock is LifeSafer Ignition Interlock. LifeSafer prides itself on its ingenuity, reliability, and price point.
What are the three main types of interlocks? ›There are three types of interlocks: – mechanical, – electrical, – logical.
Which is better interlock or transfer switch? ›Compared to a transfer switch, which is limited to a particular number of circuits, an interlock kit allows you to run power from a generator to any circuit within the electrical panel. While this is good in theory, there's a risk of overloading the generator if it's not sized according to the load.
What sets off an interlock device? ›- Spicy Foods. Spicy meals are constantly used as an example that will cause 'false positive' results in Interlocks. ...
- Sugary Foods. One of the most common culprits is yeast. ...
- Fruit & Fruit Drinks. ...
- Vinegar. ...
- Energy Drinks. ...
- Vanilla Extract. ...
- Mouthwash. ...
- Breath Spray.
Not all Ignition Interlock requirements include a camera. But when it does, this add-on accessory can be more beneficial than you may initially think. A camera requirement for your program is regulated by your state, not the Ignition Interlock vendor.
What should I turn off when connecting a generator? ›Turn OFF the homes main utility disconnect (located in either the transfer switch or homes breaker box). Then turn OFF the generators main line circuit breaker and allow the generator to run for 3-5 minutes to cool down.
How to connect portable generator to house without transfer switch? ›- Step 1: You Need an Outlet Utility Box. Cut out the space in your wall where you want to install the outlet utility box for your generator outlet. ...
- Step 2: Run Generator Cables to the Outlet. ...
- Step 3: Connect Your Generator.
No. Never run the generator indoors, in a garage or in an enclosed area. Portable generators are designed to run outside where there is plenty of ventilation. You need to position your portable away from doors and windows so that the exhaust fumes do not get inside the house.
How much is a transfer switch for generator installation? ›
A transfer switch allows you to power any of those—and skip the extension cords. Plan on a cost of $500 to $1,500 for the switch, including installation, which usually takes less than a day.
Does the interlock drain your battery? ›MYTH: Using an ignition interlock device will drain your car battery. Reality: Unless you don't start your vehicle for around 10 consecutive days, this device won't drain your battery to the point where your car can't start.
How do I hide my interlock camera? ›Place the device in a shoebox or bag where you can thread the cord (if your device has one) through the bottom of the box or bag. You can store the device in the center console. This will hide it from public view. You can also just cover the device and cord with a sweater or jacket, or even a magazine.
Can you jumpstart a car with an interlock? ›If You Need to Jump-Start Your Car
If your battery has died, and you need to jump-start your IID-equipped vehicle, it's possible, but you need to take a few extra steps. If your state allows it, disconnect the handset unit from the curly cord before you connect jumper cables or a charger to your battery.
Process interlocks prevent incorrect operation and possible damage to process equipment. Safety interlocks prevent hazards to humans and are designed to prevent death, injury, or a major process incident.
What is the difference between electrical interlock and mechanical interlock? ›Mechanical interlocking involves key system and the process of changing, opening and closing the circuit is mechanical. Extra manpower is required in switching operation of the circuit. Electrical interlocking is automation in interlocking and switching operation is performed automatically and electrically.
What is a interlock circuit diagram? ›To interconnect the motor circuit in such a way, in which the second motor will not start until the first one run likewise the third one motor will not run unless the second one run and so on. This kind of motor circuit connection is called interlocking.
How much does it cost to install a portable generator interlock? ›Interlock kits generally will set you back $1000 to $1500. Manual transfer switch set ups often run $1500 to $2500 depending on how elaborate the system. The transfer switches have a much higher parts cost and the labor is normally a few hours longer to install them. Not sure which one is best for your home?
How much does it cost to install an interlock switch? ›An ignition interlock device, also frequently referred to as a car breathalyzer, ranges in cost between $70 and $150 for installation. This fee is a one-time fee paid at the start of your lease period for the device to be installed into your vehicle.
Can you backfeed your house with a generator? ›Backfeeding is the tying of a portable generator directly to your home's electrical panel instead of using a transfer switch. It is dangerous. It is often illegal. And it should never be attempted under any circumstance.
Can peanut butter help pass a breathalyzer? ›
In short, using peanut butter to beat breathalyzer tests isn't an effective solution, and here's why: high levels of sodium found in peanuts and other legume by-products will neutralize ethanol (or alcohol) — but not by much.
How many times do you interlock? ›How often to interlock your locs depends on how active you are and how fast your hair grows. But every six weeks to 3 months is a good guide. Here are a few things you can do to keep your locs neat and extend the time between interlockings: If you can, limit activities that cause you to sweat in your scalp.
How do you trick an interlock? ›It's nearly impossible to trick an ignition interlock device because of the way the new generation of machines works. The new machines allow for rolling retests, which means that you have to blow into the machine and retest your breath while you're driving.
Who looks at interlock pictures? ›Typically, the camera is mounted on the windshield and captures the images of the person required to use an ignition interlock device. Images are stored, captured, and supplied to monitoring authorities as needed depending on your state's ignition interlock program requirements.
What is the most discreet interlock device? ›The ALCOLOCK™ V3. We can't speak for other interlock vendors, but at ALCOLOCK™, the smallest and most discreet interlock device is the V3. It's smaller than some of today's large screen cell phones, and about the size of an electric shaver. And there's a lot of technology packed into that small unit.
How do I know if my interlock has a camera? ›When your ignition interlock device is installed, the camera will often be placed in the upper right side of your windshield. This is to capture your photo when testing. It is acceptable for others to drive your vehicle but they will be required to provide breath samples and will have their photo captured.
Do you have to turn off your main breaker when using a generator? ›For an extra measure of safety, switch your main fuses or circuit breakers to the “OFF” position. Be sure you understand them before hooking up the generator. Follow the manufacturer's instructions to properly ground the generator. Generators emit carbon monoxide.
How many minutes should the generator be running in idle mode before stopping? ›Ÿ The generator is allowed to run for 5 minutes in idle condition and the stop button is pressed on the panel. Ÿ The generator is then stopped .
What happens if power comes on while generator is running? ›Feeding power back into the electrical system during an outage will energise the transformer serving your house. This is an electrocution hazard for Energex or Ergon Energy line crews and for your neighbours. If power is restored while your generator is backfeeding, it may severely damage the generator.
Can you just plug a generator into an outlet? ›Under no circumstances should you plug a generator into a wall socket, known as backfeeding. If you go the transfer switch route, get a professional installation.
Do I need an electrician to connect a generator to my house? ›
Many property owners are investing in whole-property standby generators that can power multiple systems in a home or business in the case of an extended outage. A professional electrician is absolutely essential for standby generator installation.
How do I hook up a generator to my house during a power outage? ›...
- Turn the generator off and let it cool before refueling. ...
- Store fuel in an approved safety can outside of living areas, preferably in a locked shed or other protected area.
A generator differential lockout device is usually a manually latched "reset" device that can be unlatched by any one of multiple conditions such as a current differential relay or ground differential relay.
What is the function of a locking plug on a generator? ›L1430PR is a locking plug extension cord for your generator giving you the length you need to plug in your equipment on a job site or when in need of emergency power and want the safety of keeping your generator further from your home.
What does a generator interlock switch do? ›An interlock is a device that manages the power source to the electrical panel. The interlock ensures that the generator circuit breaker and the main circuit breaker cannot be turned on at the same time.