What is the primary purpose of 'Inter-Turn Fault Protection' in an alternator?

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RRB JE EE 22 Apr 2025 Shift 1 CBT 2 Official Paper

Answer 1

Inter-Turn Fault Protection

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In this method of protection, currents at the two ends of the protected section are compared.
Under normal operating conditions, the currents are equal. Under abnormal or fault conditions, the current becomes unequal. The difference of the unequal currents under fault conditions is arranged to pass through the operating coil of the relay.
The relay then closes its contacts to isolate the protected section from the system.

Purpose of 'Inter-Turn Fault Protection'

Detect short circuits between adjacent turns of the same phase winding in the stator of an alternator.
These faults can cause localized heating, insulation damage, and even lead to catastrophic winding failures if not detected early.
Since these faults do not always cause a phase-to-ground or phase-to-phase fault, standard protections may not detect them making inter-turn fault protection critical.