Final answer:
Overcurrent protection in a CSP transformer's secondary leads is provided by devices such as fuses or circuit breakers to prevent damage and ensure safe operation.
Step-by-step explanation:
Overcurrent protection for the secondary leads in a Current-Transformer Substation Power (CSP) transformer is provided by devices such as fuses or circuit breakers. These protective devices are designed to interrupt the current flow in the event of an overload or short circuit, helping to prevent damage to the transformer and connected systems. The secondary coil in a transformer is where this protection is usually applied because it's on the side of the transformer where the energy is being delivered to the loads. Overcurrent protection ensures the transformer operates safely and prevents electrical hazards.