Description
Application
SBE voltage limiting device (VLD) protects technical installations and must be installed if the following conditions apply:
- There are metallic structures (e.g., bridges, mast structures) located less than 2 meters from the center of the tracks.
- These structures are located in an area where an overhead line (e.g., for trains) is present, or they are directly electrically connected to another railway system (e.g., in the case of shared tracks).
Important:
The SBE must be installed outside the danger zone of the tracks, i.e., where there is no direct danger to people or equipment. All cables and wires belonging to the SBE must be clearly marked.
The WITT SBE has approval from the Federal Railway Authority (ID No.: 3343340/0/016).
Function
When the input voltage curve is exceeded, the SBE trips; that is, once the trigger criteria are met, the thyristors are fired and the contactor is switched simultaneously. The thyristors switch in a few milliseconds; the contactor has a closing time of approx. 60 ms. When the thyristors fire, the voltage drops to a few volts. The thyristors remain triggered until the closing of the contactor is detected based on the position of the contactor’s auxiliary contacts. Afterward, the thyristors are turned off. The contactor then takes over the load.
The specifications described under the “Technical Data” tab also include possible options we offer for the product. Please contact us if you are interested.
