As shown in the illustrated alternator protection scheme diagram, what device provides the input to the over current inverse time relay "OCIT", the over current instantaneous trip "OC (inst.)", and the negative phase sequence relay "NPS"? EL-0067

Correct Answer: Option B — current transformer

Current transformers step down high alternating current values to safe, standardized secondary levels (typically 5A or 1A). According to IEEE 45 and marine switchboard protection schemes, these devices provide proportional current inputs to overcurrent relays and negative phase sequence protection units.