Which code is the Switch repeater relay?

• A. Vb
• B. Wp
• C. Wz
• D. Wg

Answer: (B)

In signaling maintenance, each device is identified by a two-letter code where the first letter indicates the general family and the second letter specifies the particular type or purpose. A switch repeater relay mirrors the position of a switch so that the interlocking logic and indicators can use the same switch state at different points in the system. The code that designates this device is Wp: the first letter W points to switch-related equipment, and the second letter p identifies it as a repeater. That combination uniquely names the Switch repeater relay in standard drawings and maintenance references. The other codes correspond to different device types, not repeaters, so they don’t match the function described.