ECNR50

The Eaton Edison ECNR50 is a 50 amp, 250 VAC / 125 VDC Class RK5 dual-element, time-delay fuse, designed for use in low-voltage electrical systems requiring reliable overcurrent protection with the ability to withstand temporary inrush currents. The ECNR series, originally developed by Edison Fusegear and now manufactured by Eaton’s Bussmann division, is built to meet UL 248-12 and CSA C22.2 No. 248.12 standards. These fuses are widely used in motor branch circuits, transformer protection, and general-purpose power distribution, where time-delay characteristics are critical to prevent nuisance tripping during motor starts or energizing inductive loads.

Electrically, the ECNR50 features a dual-element design, combining a long-time overload element with a short-circuit protection element, allowing it to carry 5 times its rated current for a minimum of 10 seconds—ideal for applications with high inrush conditions. With a 200,000 amp interrupting rating at 250 VAC, the ECNR50 provides strong current-limiting performance, helping to minimize damage during short-circuit events. Its ferrule ends allow installation into standard 250V-rated Class R fuse holders, and the rejection feature ensures that only fuses of the correct class and rating are installed, helping ensure coordination and safety across the system.

Eaton continues to manufacture the ECNR series under the Edison commercial brand as part of, preserving compatibility and performance with legacy installations while ensuring support for new designs. These fuses remain a staple in industrial and commercial distribution systems where overload protection, short-circuit current limiting, and code compliance are essential. The ECNR50, like other Eaton and Edison fuses, is readily available at Electrical.com, where customers can take advantage of expert support and assistance in selecting compatible fuse blocks or protective devices.