What voltage is typically used for EHV trip operation?

The typical voltage used for Extra High Voltage (EHV) trip operation is 125V DC. This voltage level is essential in the operation of relay systems in substations, particularly for the control and protection circuits associated with high voltage equipment.

EHV systems require a reliable and effective trip mechanism to ensure the rapid and safe disconnection of power in the event of a fault or operational error. The choice of 125V DC ensures stability and performance in various environmental and electrical conditions, allowing for fast response times needed during fault conditions.

In addition, many substation control systems are designed to operate with 125V DC for their battery backup systems, ensuring that they remain operational even during a loss of primary power. This voltage level strikes a balance between the necessary operational capacity and the safety of the personnel working in or around substations.