Most manufacturers recommend that if a molded-case circuit breaker has not been operated, opened or closed within six months time, it should be removed from service, and the mechanical operation and the tripping mechanism manually exercised.
Branch circuit protective devices typically fall into two categories, molded-case circuit breakers listed to UL489 or fuses listed to UL248.
Most thermal-magnetic molded-case circuit breakers are not listed and marked as current limiting.
A UL489 molded-case circuit breaker
provides branch-circuit protection in the mechanically interlocked receptacles, eliminating the need to stock fuses.
Product Scope: -- Miniature Circuit Breaker (MCB) -- Residual Current Device (RCD) -- Molded-case Circuit Breaker
(MCCB) -- Air Circuit Breaker (ACB) -- Disconnectors and Switches -- Relays and Contactors Electrical Packaged Solutions: These are integrated packages containing LV products and assemblies supplied to residential/commercial projects.
PRODUCT/END-USE MARKET OVERVIEW II-17 Choosing Between Fuses and Circuit Breakers II-17 Fuses II-17 Circuit Breakers II-18 Basic Operating Functions II-18 Thermal-Magnetic Breakers II-19 Magnetic Circuit Breakers II-19 Electronic Circuit Breakers II-19 Molded-Case Circuit Breakers
II-19 Ground Fault Circuit Interrupter Circuit Breakers II-20 Explosive Charge Circuit Breakers II-20 Shunt Trip Circuit Breakers II-20 End-Use Markets II-21 Construction Industry II-21 Electric Power Generation Industry II-21 Industrial Machinery II-21 Electronics & Electrical Equipment Industry II-22 Automotive/Non-Automotive Transportation Equipment II-22 4.
Industrial automation customers worldwide can now reap the business efficiencies of standardizing on the new global line of molded-case circuit breakers, and control-circuit and load-protection devices from Rockwell Automation.
The Allen-Bradley Bulletin 140G molded-case circuit breakers protect against overload, short circuit and ground-fault conditions.
WEG Electric Rolls Out ACW Molded-Case Circuit Breakers