More recently, the main means of protecting electrical circuits, overload and short-circuit fuses served.Technical progress did not escape this, at first glance, a simple area as break emergency devices.
Automatic electric differential helps not only when necessary to protect the wiring from overheating, it can in some cases save lives.Here it is not only dangerous circuit, but also breaks the conductors who are free to touch various objects and cause electric shock.
Auto Electric for instant blackout across the circuitry, or one of its branches, which had a critical situation.For it to accomplish this task requires simple information processing.The word "differential" in the context of the security device name indicates that it is a comparison of the values of the direct and inverse currents in the closed outlet.Opening of contacts occurs when their values are no longer coincide.
Industrial enterprises commonly used operating voltage of 380 V, and switchboards installed automatic electrical phase responsive to the accident-prone differences currents at the input and output of the circuit in each phase loads.
To illustrate the operation of this safety device, it is possible to imagine a situation in which a worker inadvertently touched the bare part of the current-carrying element.The amount of current can be dangerous to life is approximately 20 mA.Are exposed to it, as a rule, can not release the conductor, because of which the contact for a period of a few seconds can be lost.
Automatic electric differential configured to operate at 10 mA leakage current, will not affect long strikes stress on the body.Man will experience discomfort, but after the chain will immediately de-energized, his life will be safe, spasm of the heart muscle does not happen.Thus in any other case, the machine will pass through your contact current group to which it is designed.
The same situation arises in the case of breakage, when the wire touches any grounding element.
Short-circuit protection is activated immediately when the value exceeds the allowable current.Provided wiring and safety in case of a relatively small, but a long passage through excessive load.Thus, automatic electrical isolation protects from drying out, and the contact group - from premature burnout.
This protective equipment is used not only in the production halls, it is widely used in living rooms (apartments, houses).Automatic single-phase electric increasingly replacing cork, which is a disadvantage in having to constantly be on hand fuses.It is no secret that for a long time became a common practice to replace them with "bugs" that often leads to fires.Automatic after removing the cause of the short circuit just enough to include.