14 Years Factory Miniature Circuit Breaker FTB1 for Mauritius Importers
Exterior and dimensions
As a result of ours specialty and service consciousness, our company has won a good reputation among customers all over the world for 14 Years Factory Miniature Circuit Breaker FTB1 for Mauritius Importers, We warmly welcome your participation based on mutual benefits in the near future.
|Auxiliary contact||Auxiliary contact and alarm contact||Shunt release||Shunt release and auxiliary contact||Under voltage release||Over voltage release||Busbar mounting base||Motor-driven operation|
Under normal condition, the working principle of main thermostic bimetal in FTB1 SMCB is the same to the usual circuit breakers, it is used for overload tripping. when there is a short-circuit on a branch circuit breaker, the magnet core in the main current path would tilt the moving contact away from the fixed contact to break the circuit,thus producing the electric arc, and limiting the short-circuit current effectively.
In the maintime,the short-circuit current flow to the supplementary current path, a selective resistor and a selective bimetal are connected in series of the supplementary curret path, limiting the short-circuit current to a few hundred amps.
When the downstream circuit-breaker has tripped because of a short-circuit, the contact tips reclose automatically through a simple spring-type system,ensuring other unaffected branch circuits continue in operation.If a short-circuit occur between the FTB1 and the downstream circuit-breaker, another bimetal release enables short-time delayed tripping,ensuring the contact tips remain in the open position enabling isolating.
Scope of use
It is primarily used in critical installations,for instance, office buiding, laboratory, theatre, museum, hotel, shopping mall, telecommunication, coal mine and shipping, chemical industry and metallurgy, industrial plants,medical and health care, bank and securities exchange,airport, underground express way, military establishment and similar loads that requires non-interrupted and reliable power supply.
|Test||Tripping characteristic||Conventional non-tripping current||Conventional tripping current||Initial status||Tripping time|
|a b||E E||1.05In||1.2In||Cold statusRight after test 1||≧2h﹤2h|
|Test||Tripping characteristic||Delayed tripping current||short-time delayed tripping current||Initial status||Tripping time|
|c||E||5In||Cold status||0.05s<t<5s(In≦32A) 0.05s<t<10s(In>32A)|
The FTB1 series operates selectively with respect to the combination with MCBs
|MCB(B,C characteristic) FTB1(Characteristic E)|
Note: T represents total selectivity
Exterior and dimensions
Augustus Depuy’s breaker assembly. A problem of telegraph and telephone communications protection against natural sources of high pulse voltage such as lightning arose in the first years of these communications. One of problem solution ways is usage of breaker assembly, its prototype was offered in 1895 by an American engineer Augustus Depuy. This mechanism was called an electrical shunt device. It consists of a magnetic needle of about 4-inch length positioned on insulation slate foundation and fastened to it with a rubber suspender. One of needle halves is inside the bobbin made of thick copper wire and is connected consequently with protected information line that usually doesn’t make any influence on it because of very low resistance. But as soon as abnormal current produced, for example, with lightening or crossing of telephone conductors with household electrical conductor or with electric transport conductor flows through main lines and while flowing through a bobbin causes deviations, their type depends on current direction, and in any case a movable contact contacts with springs and current is not delivered through metal wires following the path of least resistance to the ground or in a circuit outside the device. Being improved because of necessity to protect not only constant current but also alternating current lines this device has been widely used in devices called automatic safety device or fuse.