What is a differential circuit breaker?

Thanks to the active development of new technologies, a special type of switch has appeared - a differential automatic switch. This attribute is better protected from electric shock. If there is a short phase-to-phase fault or a short to ground, the automaton operates almost instantaneously, and is therefore often used in hospitals to supply high-sensitivity devices.

Structurally, the device is made of two units: a differential protection module , made on an electronic base, and the switch itself.

Today, ABB automatic circuit breakers are quite popular. The quality of their production allows you to be confident in the reliability and reliability of the device.

The electronic module of the automaton includes a current transformer, by means of which the differential of the value change is calculated. The transformer works in conjunction with an amplifier that serves to accurately determine the jump.
Installation of the switch is made on a special DIN-rail with a plastic latch. Thus, the machine is easy to maintain and very simple to replace.

ABB - automatic switches of the new generation, their work is based on comparing the currents of the incoming currents with outgoing ones. When the machine is switched on, the electronic module is powered up, while the connected load creates working current. With the help of a transformer, the direction of currents and their magnitude are determined. In the normal mode, the vectors are reversed, and their algebraic sum is zero.

If the differential circuit-breaker closes to ground, then, along with the load current in the circuit, there is a leakage current - this is the difference between the incoming and outgoing values. As soon as the leakage current exceeds the threshold of the set point, the secondary winding of the current transformer sends a signal to the tripping coil of the machine.

Using the "Return" button, you can squirt the differential circuit breaker and try to re-enable it. In order to monitor the operability of the machine, it has an electronic circuit for testing the device. There is a "Test" button on the front panel. With its help, it is possible to artificially create a disconnecting leakage current. If the machine has worked quickly and without jamming, then it is normal and ready for further use.

The main advantages of a differential circuit breaker are, of course, the speed of operation. In addition, these machines can protect the circuit in three ways:

• Protection against overload of current circuits;
• Interfacial short-circuit protection;
• Earth fault protection.

Manufacturers offer different types of differential automata. The total number of types and models exceeds 40 units, with each operation being accompanied by a special indication, informing about the accident.

The minimum service life of such switches is from 15 years and above. Other advantages of the device include an improved design of the control module, a fairly wide range of temperatures at which the machine can operate reliably: -25 ° C to + 40 ° C. Thus, the diaautomatics are excellent devices for combined protection of equipment, but are not recommended for use in everyday life, as they are quite sensitive: there may be problems with frequent trips. Differential automatons are sufficient even for small leakage when heating an electric kettle, which happens quite often.