How does the automatic differential

More recently, the main means of protecting electrical circuits from overload and short-circuit was the fuses. Technical progress has not passed and such, at first glance, a simple area, as the disconnecting emergency devices.

Automatic differential electric helps not only when you need to protect the wiring from overheating, it can in some cases save human lives. At the same time, dangerous are not only closures, but also breakages of conductors, which can freely touch different objects and cause electric shock.

An automatic electric device is designed for instantaneous de-energizing of the entire electrical circuit or the branch in which a critical situation has arisen. In order for it to fulfill this task, it is necessary to easily process information. The word "differential" in the context of the name of the protective device indicates that it compares the values of the forward and reverse currents in a closed electrical network. Opening of contacts occurs in the event that their values cease to coincide.

In industrial plants, the working voltage is usually 380 V, and an automatic three-phase automatic device is installed on the switchboards, reacting to the emergency-dangerous divergence of the currents at the input and output of the circuit in each of the phase loads.

To illustrate the operation of this protective device, it is possible to imagine a situation in which the employee, through carelessness, touched an uninsulated part of the current-carrying element. The magnitude of the current representing a danger to life is approximately 20 mA. Being exposed to it, as a rule, can not release the conductor, because of which it can die for a few seconds.

Automatic electrical differential, configured to operate with a leakage current of 10mA, will not give the damaging voltage a long time to work on the body. The person will experience unpleasant sensations, but after the chain is instantly de-energized, his life will be safe, a spasm of the heart muscle will not occur. In any other case, the machine will pass through the contact groups the current to which it is calculated.

The same situation will occur in the case of breakage, when the wire touches any grounding element.

The short-circuit protection is triggered instantly when the permissible current is exceeded. Provision is also made for the security of the wiring in the case of a relatively small but prolonged passage through it of excessive load. Thus, the automatic device protects the insulation from drying out, and the contact groups - from premature burning out.

Such protective equipment is used not only in production workshops, it is widely used in residential premises (apartments, houses). The automatic one-phase automatic machine more and more actively replaces the plugs, the inconvenience of which consists in the necessity of constantly having at hand fusible inserts. It's no secret that common practice has long been their replacement with "bugs", which often leads to fires. The automaton after eliminating the cause of the short circuit is just enough to turn it on.