All Articles

Transformer load break switches

A transformer load break switch (or LBOR switch) switches the transformer's power on or off. Learn about 2- and 4-position switches (for loop-feed systems).

July 1, 2021

Four Position T-Blade Load Break Switch

What is a transformer load break switch?

A load break switch or LBOR switch is an “on / off” switch, similar to an “on / off” light switch in your house. A load break switch is designed to switch the power “on or off” or change the position when the transformer is energized (meaning it has a load on it)—the switch will break this load. A more formal definition of a Load Break Switch is “a disconnect switch that has been designed to provide making or breaking of specified currents.”

Note that this “making or breaking” of the electrical current is typically accomplished by someone with a “hot stick” from the local utility or a trained electrician.

Types of transformer load break switches

The two most common types of load break switches are the 2-position switch and the 4-position switch.

2-Position load break switch

2 position transformer load break (LBOR) switch

The 2-position switch only allows for two settings: on or off.

2 position transformer load break (LBOR) switch shown from three different angles

4-Position load break switch

4 position transformer load break (LBOR) switch

The 4-position switch is used for loop feed transformers and allows for four different switch settings:

  • Position 1 - A-side on and the transformer on (energized)
  • Position 2 - B-side on and the transformer on
  • Position 3 - A & B-side on and the transformer on
  • Position 4 - A & B-side on with the transformer off (not energized)
4 position transformer load break (LBOR) switch shown from three different angles

When the transformer is in Position 4 then it's just feeding through: the bushings are energized but the transformer itself is not.

Hopefully you found this information helpful! Check out our short 1-minute video that explains this too.

Do you have other transformer questions we can answer? Learn more about what electrical transformers are, and how they work.

Maddox padmount transformer loaded on truck

Get more info

Find out how Maddox can power on your next project
Thank you!
Your submission has been received!
Oops! Something went wrong while submitting the form.