Precision Products Aircraft Circuit Breakers - Sensata

2TC49 Series“Dual Safety” Circuit BreakersFeatures• Extension of 2TC series• Redundant protection in hard faultcatastrophic conditions• Separable link feature• Case color distinguishes 2TC49 from 2TC series• Uses less space and weighs less than othercircuit breaker packages• Rating 2 1 ⁄2 -15 amps2TC49“Dual Safety” Circuit BreakerOverviewThe 2TC49 “Dual Safety” circuitbreaker represents a refinementin electrical control and circuitprotection. The 2TC dual safetycircuit breaker incorporates afusible element in a standard 2TC(MS 3320) package size toprovide redundant protection inhard fault conditions.“Hard Fault” TrippingThe 2TC dual safety circuitbreaker operates identically to astandard circuit breaker under allnormal conditions, includingshort circuit. In the event ofcircumstances which disable theinternal circuit breakermechanisms, such that the deviceis able to carry current but unableto clear an overload via its normalmeans, the dual safety elementacts as a built in fuse to provideredundant circuit protection.The key part in the dual safetydesign is a two part currentcarrying element joined by aspecial alloy. The geometry andmaterial of the element determineits heating properties. Theelements heating properties areslower than the bimetal sensorbut faster than the smoke curveof the wire the rating is designedto protect. In the case where thestandard mechanism is disabledor cannot operate normally, theseparable element “fuses” open,interrupting the current.The benefits of the dual safetydesign result in calibratedovercurrent protection (basedon fuse times) and specified postfuse dielectric properties forsystem and human protection.