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Generator Interlock vs Transfer Switch: Which One is for You

A generator switch is very significant to have control over the power. But different switches provide different features. It creates confusion when you have two competitive options like generator interlock and transfer switch

Which one should you pick from generator interlock vs transfer switch?

Both the generator interlock and transfer switch provide versatile features. The transfer switches are costlier but can handle 6-10 circuits at a time. Again, it operates automatically and shifts power. The interlock is good for small premises where continuous power is not required.

Are you convinced to find which one is better for you? You don’t have to rush. This article contains all the factors that will help you decide. 

Hover aboard!

Generator Interlock vs Transfer Switch: General Overview

When the electricity goes out, a standby or backup generator might come in handy. The generator kicks up after a storm and provides power to the electric devices.

But the real problem is when there is a blackout. How would electricity be transferred from grid power to backup power? 

An automated transfer switch or an interlock may be required depending on your power requirements. It also depends on your application criteria. The action of the power going off is determined by the sort of switch you use.

Generator Interlock

The interlock prevents the generator circuit breaker from turning on at the same time as the main circuit breaker. The interlock ensures that anyone working on the electrical wires is safe. 

It also protects the building from experiencing harmful electrical feedback. But a breaker box outside your home might cause a lot of problems. So it’s better to keep the breaker inside your home where it is safe from environmental hazards.

Transfer Switch

A transfer switch can also be referred to as a transfer panel. Some backup generators have it pre-installed. It’s a straightforward switch that splits the electrical load between two power sources. It also allows you to flip between them easily. 

It contains a switch for each circuit breaker. And so it can control 6 to 10 circuits at the same time. If you only need to power one or two appliances, it’s also a good option. 

Consider a refrigerator or lighting. There are two types of transfer switches: manual and automated.

Generator Interlock vs Transfer Switch: Head Start

Before you get to the discussion, here’s a quick insight into what you’ll find. This will help you get a basic idea about the two. 

FactorGenerator InterlockTransfer Switch
InstallationSimple Simple
FunctionalitySuitable for small businessBest for heavy-duty
CostAround $700 – $800$2000+

If you understand what you’re getting into, continue to the detailed discussion below. 

Head-to-Head Comparison

There are several elements to consider when determining which is ideal for your application. You’ll want to think about things like electrical load, on-site operator availability, etc. 

Also, consider the set-up cost of the transfer switch and generator interlock. If you’re not careful, you might have to pay a hefty fee.

So, let’s get down to business.


Your electrical panel is equipped with an interlock kit. A generator breaker is used to control the flow of generator electricity through the panel. 

Consider installing a weatherproof intake box on the exterior of your home. A generator power extension cord is also required to connect the generator to the input box. 

Your electrical panel is equipped with an interlock kit. A generator breaker is used to control the flow of generator electricity through the panel. 

In my opinion, the installation of both switches is pretty easy. There is nothing complicated.


An interlock is a device that is turned on and off manually. Its functionality is known when the utility power goes out. The main power breaker’s interlock switch is switched to the generator breaker. It is generally used at home or light business.

An automated transfer switch connects your generator or supplemental power source to your main power source. It works when there is a power outage. It will commence when your major power source fails. 

Advanced transfer switches can be operated and accessed remotely.

Are you searching for some good switches? Here get some good deals:


The recommended items are reasonable in price. Now let’s get back to the main part.

Each circuit breaker has its own switch. So you can wire multiple wires just like you can wire multiple circuits in one junction box

As a result, it can control multiple circuits at once. It guarantees that the panel is not fed by both main and generator power coevally. If you only need to power one or two appliances, it’s also a good option.

I think that the transfer switch is better in this factor. It’s because it gives you the scope to operate remotely. And also it can control 6 to 10 circuits at the same time. But as more functions it will provide you, it will cost more too.


A generator interlock will set you back for a minimum of $350. And you can go as high as $700 – $800. This includes the labor cost. And also the accessories that you need. This includes the power boxes, breakers, cords, etc.

The transfer switch has a very wide price range. The six-circuit switch costs around $650 – $700. This includes the charge of the electricians which is around $200 to $400

The ten circuit switch will set you around $750 to $900. The charges of the electrician will be the same of $200 to $400. The switch alone will cost around $350 – $450. But while installing, a 400 amp switch will set you back to around $2,700

The transfer switch can be said to be more expensive than the interlock. But there are reasons for the cost. 

Final Verdict

As you finish the whole discussion, you clearly know which features are good in which.

Interlocks are best for smaller projects like residences or small businesses. To be more precise, the applications that don’t require power all day. And obviously, you’ll need someone to operate it on-site manually.

The transfer switches give you a fully automated system that requires no inspection at all. It is the best option for industrial applications or commercial use. Because it can provide power continuously and can transfer power automatically. 

It’s entirely up to you to decide based on your needs.. 


Question: Is it possible for me to install a generator transfer switch myself?

Answer: Yes, you can technically install a generator transfer switch yourself. But you must have the requisite skills and comfort in dealing with electronics.

Question: Is it necessary to switch off the main breaker when running a generator?

Answer: Before starting it up, you’ll usually need to turn off the circuit breaker. Then switch on the fuel valve. Allow the machine to warm up for a few minutes before turning on the circuit breaker.

Question: How many watts do I require to run my home?

Answer: Essential devices in a normal house use between 5000 and 7500 watts of power to operate. The fundamental electrical demands of an ordinary American house range from 30 to 50 kilowatts.

Summing Up

I hope I could help you decide between generator interlock vs transfer switch. To remind you of the importance of this discussion, the absence of a switch can destroy your generator.

So I wish you the best of luck in making the finest decision possible.

Best wishes!