Schneider Electric 5NR-151 Current Transformer

Schneider Electric's Square D 5NR-151 current transformer delivers a 150:5 A ratio in a solid-core through‑conductor design, ideal for precise current measurement and relay feeding in electrical distribution equipment. With a 1-9/16 in (1.56 in) bore, it accommodates the primary conductor and provides a 5 A secondary output for compatible metering and protection devices, rated for 50–400 Hz operation. The unit carries a 600 V insulation class and a 10 kV basic impulse level (BIL), enabling safe use in medium‑voltage installations. Common applications include feeding metering instruments and protective relays in switchgear, panels, and motor control centers, where a reliable, low‑impedance current signal is essential for accurate monitoring and system protection. Installers should ensure the primary current remains at or near 150 A to maintain the correct ratio and connect the 5 A secondary to the appropriate device inputs, following all applicable electrical safety standards and device specifications.