Enhanced Safety: No exposed metallic parts. The ST Switch features a finger-safe design to maximize user protection during testing procedures.
Keyed Disconnect Pins: Each disconnect pin is keyed to its corresponding slot, minimizing the risk of incorrect insertion and operational errors.
Visual Status Feedback: Integrated front-facing status windows allow operators to visually confirm whether contacts are open or closed.
Low Internal Resistance: With less than 2 mΩ internal resistance, the ST Switch ensures accurate signal transmission and reduces stress on instrumentation transformers.
Wire Terminal Options: Available with both screw and stud terminals, replicating FT Switch configurations for maximum compatibility and convenience.
Retrofit-Ready Design: Perfect for replacing older FT Switches. Compatible with existing panel cutouts and terminal labeling—no need to update engineering drawings.
Efficient Secondary Testing: Banana jacks on the front panel facilitate fast and simple execution of secondary injection tests without reconfiguring the system.
Modular Pole Configuration: Offered in even-numbered configurations from 4 to 20 poles, enabling flexible adaptation to various applications.
Fail-Safe Operation: When a disconnect pin is inserted, the circuit is completely isolated. Internal shorting bridges in current circuits ensure safety. There is no intermediate position, eliminating partial contact risks.
Normally Closed Default: Once the disconnect pin is returned to its parking position, internal springs re-establish the closed-circuit state automatically and reliably.
Technical Details
Key Features
Details
Downloads
Key Features
Finger-safe – There are no exposed metallic parts on the ST Switch, greatly increasing safety during testing.
Keyed Disconnect Pins – Disconnect pins are keyed to the corresponding slots of the test block, preventing mistakes and errors during test.
Integrated Status Window – Status windows in the front of the ST Switch allow visual inspection of the internal contacts position (open or closed).
Wire Terminals – Wire terminals are replicated from the FT Switch and offer maximum convenience for technicians and engineers. A screw terminal and a stud terminal version are available.
Less than 2 mΩ internal resistance – Thanks to the patented construction, ST Switches boast an extremely low internal resistance. This ensures a lighter load on instrumentation transformers and no impact on heat generation within panels.
Ideal for Retrofit of Older FT Switches – The ST Switch models are available in any even number within the range of 4 to 20-pole configurations. 10-pole ST Switches have the same panel cutout as legacy FT switches. Even the terminal labeling is the same. That means that you can have the increased safety and efficiency from the ST Switch without having to change your engineering drawings.
Details
Closed Circuit
An ST Switch contains any even number of poles within the range of 4 and 20, each allocated to a current, voltage, signal, or trip circuit. Each circuit is connected through the block via two silver-plated copper contacts, pressed securely together by two pressure springs to create a highly conductive electrical connection.In this situation, an electrical connection is established between the device side (B) and the system side (A).
Open Circuit
To open one of these modular poles, a disconnect pin is removed from its inactive “parking” position and inserted between the silver-coated copper contacts (the “test” position). In this position, the device and system sides of the test block are isolated from each other.For current circuits, the disconnect pins include internal shorting bridges. When the pin is moved back to the “parking” position, the internal springs force the contacts back together, returning the circuit to its normally closed position.There is no in-between position, completely eliminating the risk of accidents resulting from improperly closed circuits.
Downloads
For technical documentation and product details, please reach out via email or our contact form.Click here to connect with our team.Other documents:>> STS-flyer.pdf
