June 6, 2012—The National Electrical Manufacturers Association (NEMA) published ANSI/NEMA C37.50 Low-Voltage AC Power Circuit Breakers Used in Enclosures—Test Procedures.
The first new edition in twenty four years, ANSI/NEMA C37.50 covers the test procedures for enclosed low-voltage ac power circuit breakers as follows: a) Stationary or drawout circuit breakers of two-, three-, or four-pole construction, with one or more rated maximum voltages of 635 V (600 for units incorporating fuses), 508 V, and 254 V for application on systems having nominal voltages of 600, 480, and 240 V. b) Unfused or fused type circuit breakers. c) Manually operated or power operated circuit breakers with or without electromechanical or solid-state trip devices. d) Fused drawouts consisting of current-limiting fuses in a drawout assembly intended to be connected in series with a low-voltage ac power circuit breaker to form a non-integrally fused circuit breaker.
This document applies to both integrally and non-integrally fused circuit breakers.
ANSI/NEMA C37.50-2012 may be downloaded at no cost at www.nema.org/stds/c37-50.cfm. NEMA is the association of electrical equipment and medical imaging manufacturers, founded in 1926 and headquartered in Arlington, Virginia.
Its member companies manufacture a diverse set of products including power transmission and distribution equipment, lighting systems, factory automation and control systems, and medical diagnostic imaging systems. Worldwide annual sales of NEMA-scope products exceed $120 billion.