Interlock vs. Transfer Switch; which is better for you? When the storm or hurricane hits your residence, a lot can go wrong. Of course, standby or a backup generator becomes a lifesaver in times like this. When the power goes off abruptly, the backup power with light up the house, run the ventilator, fridges; charge your devices and more. Before you we get to the main topic of this post, Interlock vs. Transfer Switch, it’d be best you understand what these two things are.

Why Do You Need a Transfer Switch or an Interlock Kit for Your Generator?

Let’s assume you have installed one of the two backup options, a standby or portable generator. How will your electricity transfer from the utility power to the backup power when the unfortunate power blackout occurs? That’s why you need an interlock or a transfer switch. The two turns off the main power line and turn on the backup when there is a power blackout. The type of device you decide to use will determine what happens when your power goes out.

Each of these safety devices does determine how power line is switched from the mainline to the generator backup power. You want approved switch installed with accordance to the state set electrical codes for safe generator use. Both switches work excellently in preventing dangerous conditions that might cause harm to electrical workers. They also block potential damage to your building and the connected electrical appliances and devices.

 

Interlock vs. Transfer Switch: which is better for you?

These two devices work with the same principle – they allow power to switch from the main power line to the backup line and vice versa. Nevertheless, the mechanism of these two things is quite different. I’m going to take you through what they are, how they work and lastly, which is better for you. Read along!

What’s a Transfer Switch?

A transfer switch is a device designed to allow you to hook up a backup generator to your home wiring safely. It’s installed near the main electrical panel with a dedicated outlet using one cord. It looks like another separate electrical panel but only has limited 6-8 circuit breakers.

A transfer switch gives you a spate line that powers most of your most necessary circuits with appliances like the sump pump, refrigerator, lights and much more. It gives you the freedom to choose the circuits that need backup power most.

 

Types of Transfer switches

There are two types of transfer switch: an automatic model and a manual model. Their functionality is the same, but the principle of operation is different.

An Automatic Transfer Switch: this model senses the power loss in the main electric panel, switches it off and switch the power backup line on. It doesn’t require you to attend to it and do the line change manually. It will do the reverse when the main power gets restored.

A Manual Transfer Switch: With this model, everything is done manually. Once there is a power blackout, you have to go down to the basement or wherever your power panel is, shut off the main electrical panel, turn on and connect the generator backup power line.

The two works the same; the difference is, you have to turn on and off the manual transfer switch. It’s mostly used with portable generators while the automatic model is used with standby generators. Why? These models are automatic; they will start themselves up when the main power goes off and shut down when the power gets restored.

 

How Does a Transfer Switch Work?

With a typical setting, a generator transfer switch will ensure power switching from the main electric panel to the backup power panel is done efficiently and safely.

When there is a power blackout, the transfer switch allows you to plug in the backup generator through an external power inlet and turn on the specified circuits in the transfer switch.

You have to follow the right electrical codes within your area to have the transfer switch installed. Why? It’s a permanent additional unit that requires safety measures followed by a licensed electrician.

What’s an Interlock?

Similar to a transfer switch, an interlock device manages how you operate the electrical panel together with your backup generator panel. The device ensures the main electrical breaker and the generator circuit breaker can ever be on at the same time. It guarantees your safety and any other person working on your electrical lines. It also prevents any potentially dangerous electrical feedback.

How Does an Interlock Work?

What you need to know is, an interlock device is manually operated. You have to move it from the main power breaker to the backup generator breaker when your power goes out. Your main breaker and other breakers connected to it must be off and the interlock set to the backup generator and then engaged. You have to turn on the main breaker on the power panel while the main electric inlet breaker is off to energize the main panel. Once that is done, turn on the individuals’ breakers as per your needs.

 

Automatic Transfer Switch vs. Interlock: Which Is Best Your Application?

Before you can decide what suits you best, you have to understand what you need it for. You need to consider the type of generator you have; is it a standby generator or a portable generator? What’s more, you need to consider the generator size, your electrical load, outages duration and frequency, availability of on-site operators, and building occupant’s demands. You might also need to check your budget and the cost factor.

When to Use an Interlock

It’s a less sophisticated and it’s a less expensive option compared to a transfer switch. The device application is mainly residential and small commercial usage, applications that don’t require continuous power. It’s easy to operate. However, you do need additional power management for turning off the circuit breakers exceeding your generator capacity. You need the training to know how it works.

When to Use a Transfer Switch

A transfer switch is mostly applicable in a situation where the power needs to go on automatically. You will find this switch in commercial buildings that require alternate backup power for safety purposes and to comply with the set National Electrical Code and other building codes. You can also install it residentially if you live in a place that experiences frequent power outages.

Final Verdict!

These two devices work the same. However, their operability is different. Their applications are also various. With an interlock being used in residential applications and places with less frequent power outages, an automatic switch is mainly commercial and in those vast apartments. You need an automatic switch if you prefer having a fully automated system requiring no supervision. It’s also ideal for commercial or industrial applications needing continuous power. You need one of these devices in your home if you have a backup power generator. It’s also a requirement for any commercial building to have backup power with a transfer switch.

Related Information:

• How to Connect Generator to House without Transfer Switch