Interposing Relay Panels are essential interfacing modules within substation protection and control systems, designed to provide electrical isolation, voltage level conversion, contact multiplication, and signal amplification between primary protection relays, control systems, and the switchgear equipment they operate. These panels incorporate a comprehensive array of interposing relays, auxiliary relays, time delay relays, hand reset lockout relays (86), terminal blocks, test facilities, indication LEDs, and wiring marshalling arrangements ? all housed within a robust CRCA sheet steel enclosure conforming to IP42 or higher protection standards. The primary function of interposing relays is to bridge incompatible voltage and current signal levels between numerical protection relays operating at 24V or 48V DC and high voltage trip coils, close coils, or motor-operated mechanisms requiring 110V or 220V DC supply, ensuring reliable and accurate command transmission without direct electrical connection. Contact multiplication capability allows a single protection relay output to simultaneously initiate multiple tripping, signalling, and alarm functions across different circuits and panels, enhancing system redundancy and operational flexibility. Lockout relays (86) provide latching functionality, maintaining trip commands until manually reset by operators, preventing inadvertent re-energisation of faulted equipment. Marshalling and terminal arrangements facilitate organised cable termination, simplifying commissioning, testing, and maintenance activities. Designed and tested in accordance with IEC 60255 and IEC 61439 standards, Interposing Relay Panels support seamless integration with SCADA, RTU, and DCS systems through IEC 61850 and Modbus communication interfaces. Widely deployed across 11 kV to 220 kV substations in power utilities, industrial plants, renewable energy installations, and railway traction systems, they serve as the vital signal interface backbone of any substation protection, control, and automation architecture