Overview of differences between LV Power Circuit Breakers, Insulated-Case Circuit Breakers and Molded-Case Circuit Breakers

There are two main classifications of low voltage circuit breakers—molded-case circuit breakers and low voltage, power circuit breakers. All UL®, NEMA® and ANSI standards are for molded-case circuit breakers and low voltage
power circuit breakers. The industry recognizes three types of circuit breakers— molded-case circuit breakers (MCCB), insulated-case circuit breakers (ICCB) and low voltage power circuit breakers (LVPCB). Insulated-case circuit breakers are designed to meet the standards for molded-case circuit breakers.

Low voltage power circuit breakers comply with the following standards:
■ ANSI Std. C37.16—Preferred Ratings
■ ANSI Std. C37.17—Trip Devices for LVPCB
■ ANSI Std. C37.50—Test Procedures
■ IEEE® Std. C37.13—LVPCB Used in Enclosures
■ UL 1066—LVPCB

Molded-case circuit breakers and insulated-case circuit breakers typically comply with the following standards:
■ UL 489—MCCB
■ UL 489—Molded-Case Switches (MCS)
■ NEMA AB1—MCCB and MCS
■ NEMA AB3—MCCB Application