What does RCD stand for in the context of substations?

In the context of substations, RCD stands for Residual Current Device. This device plays a critical role in electrical safety by detecting imbalances in electrical currents. When it senses that the current flowing through the live and neutral wires is not equal, which could indicate leakage current to the ground or a fault condition, it automatically disconnects the circuit to prevent electric shock and protect against potential fire hazards. RCDs are crucial for ensuring the safe operation of electrical installations, especially in environments where water presence is more likely, as they provide an essential layer of protection for personnel and equipment.

The other definitions provided do not align with industry terminology or purposes related to electrical safety and protection in substations. Rapid Current Device, Relay Control Device, and Resistive Current Divider do not serve the same safety function as a Residual Current Device, which is specifically designed to monitor and mitigate risks associated with current leakage.