Off Circuit Tap Changer

An off-circuit tap changer (OCTC), also known as a de-energized tap changer (DETC) or no-load tap changer (NLTC), is a device used in transformers to adjust the voltage by changing the number of winding turns. It can only be operated when the transformer is de-energized, meaning it's not under load and disconnected from the power supply. 
Key Feature:
An Off Circuit Tap Changer is a device used in transformers to adjust the voltage by changing the tap position without the need for the transformer to be under load.
It allows operators to change the transformer’s voltage setting manually while the transformer is offline, ensuring safe operation and voltage regulation.
Commonly used in applications where fine voltage control is needed but under no-load conditions, such as in distribution transformers.
Helps maintain stable voltage levels and optimize transformer performance, especially during maintenance or voltage adjustments.