ZE corresponds to which device?

• A. Bell
• B. Exit push button stick repeater relay
• C. Contact rail indicating relay
• D. Contact rail alarm indicator light

Answer: (D)

ZE is the designation used for the alarm indicator associated with the contact rail. In signaling diagrams, such two-letter codes label the exact device, and ZE specifically points to the visual alarm light that lights up to warn of a fault or abnormal condition on the track circuit or contact rail. It’s a dedicated visual indicator for maintenance and operations.

The other devices serve different purposes: a bell provides an audible alert, the exit push button stick repeater relay is a relay related to pushbuttons and their indication, and a contact rail indicating relay signals status through a relay coil but is not the alarm indicator itself.