come funziona un breaker magnetoidraulico?

[Fede55]

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in pratica, in ambienti umidi o freddi, dove il normale interruttore termico potrebbe avere qualche problema di funzionamento anticipato o troppo veloce, gli viene aggiunto un "ammortizzatore" idraulico che rallenta leggermente la risposta al sovraccarico istantaneo...
Questo è quanto ho capito io!

"Hydraulic-Magnetic Circuit Breakers
This type of circuit breaker is used whenever site conditions would interfere with the normal operation of thermal overload protection, including cases such as:
Low temperatures, which might prevent thermal protection from tripping.
High temperatures, which may trip thermal protection without an overload.
Environment moisture, which may absorb heat and affect the operation of thermal protection mechanisms.
Hydraulic-magnetic circuit breakers, whose overload protection is independent on temperature, offer a suitable solution for applications such as marine environments, transportation, generator rooms, and any industrial location with temperature or moisture extremes.

Hydraulic-Magnetic Circuit Breaker Operation
As mentioned before, thermal-magnetic circuit breakers accomplish their protection function through a combination of two elements: an expanding contact for overload protection and an induction coil for fault protection. Hydraulic-magnetic circuit breakers, on the other hand, accomplish both types of protection with an induction coil whose mechanical actuator is dampened by a fluid-filled cylinder.
If there is an overload, which only exceeds the rated current slightly, the induced magnetic field will be weak and the circuit breaker's trip will be delayed due to the dampened cylinder.
If there is a high-current fault, the induced magnetic field is very strong and the dampening effect is overcome instantly- providing an immediate trip."