Schneider Electric 7RL-501B Current Transformer

Schneider Electric’s 7RL-501B current transformer (often cataloged as 7RL501) is a window-type instrument transformer designed to surround a single conductor and deliver a 5 A secondary from a 500 A primary, i.e., a 500:5 ratio (100:1). It is a non-ANSI rated CT intended for metering and instrumentation use rather than protective relaying, with a 63.5 mm (2.5 in) window opening to accommodate standard conductors in panel installations. The device operates over a 50 Hz to 400 Hz frequency range and supports a 25 VA burden, enabling accurate signal transfer into typical metering equipment without undue voltage drop or phase shift. As part of Schneider Electric’s Square D instrumentation family, the 7RL-501B is positioned for window installations in electrical panels where a conductor passes through the opening to produce a reliable secondary for measurement. Catalog listings consistently reference the 500:5 ratio for this model, ensuring compatibility with equipment that expects a 5 A secondary.