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
The 2-position switch only allows for two settings: on or off.
4-Position load break 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)
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.