An Off Circuit Tap Switch is a manually operated transformer accessory used to adjust the voltage ratio of a transformer by selecting different tapping points on the transformer winding. It is designed for applications where voltage adjustment is required while the transformer is completely de-energized and electrically isolated. distribution transformers, power transformers and industrial transformers. By providing multiple selectable tap positions, the switch allows the transformer voltage ratio to be adjusted according to the required operating conditions.
 
The Off Circuit Tap Switch operates through a manual handle and mechanical shaft arrangement connected to the transformer winding taps. When the required tap position is selected, the switching mechanism establishes a reliable electrical connection with the corresponding winding tap. Different designs and configurations are available depending on the transformer rating and application.
 
Features of Off Circuit Tap Switch
Manual operation with clearly defined tap positions
Suitable for oil immersed transformers
Robust mechanical construction for dependable operation
Reliable contact arrangement for secure electrical connection
Available with different numbers of tap positions
Suitable for different transformer current and voltage requirements
Different shaft lengths and mounting arrangements available
Compact design suitable for transformer installation
Configurable according to transformer winding requirements

Applications
Off Circuit Tap Switches are commonly used in distribution transformers, power transformers, industrial transformers, furnace transformers and other oil-filled transformer systems. They are particularly useful where the transformer voltage needs to be adjusted periodically to compensate for variations in supply voltage or to obtain the required secondary voltage.
The appropriate switch configuration depends on factors such as transformer kVA rating, winding voltage, current rating, tap range, number of tap positions, winding connection and installation arrangement.