Circuit breakers

Machines are designed to protect against short circuit and overload protection of electric lines and receivers of energy to enable or disable lines, and receivers of energy. Circuit breaker consists of the following: Contact the system. The mechanism of a free trip. Release (solenoid and thermal). Arc chute. Contacts are designed specifically for switching electric circuits. The mechanism of a free trip allows you to switch automatically or manually. Trip units provide a circuit breaker for overload and short circuit (thermal and electromagnetic, respectively). Of the heat release is based on a thermal current action: the passage of the current exceeds the nominal heated bimetallic plate, due to the difference of thermal expansion coefficient of metals from which it is composed, bends and affects the mechanism of a free trip. Electromagnetic release acts as a relay with an anchor: when the flow of current short-circuit anchor driven by an electromagnetic field affects all the same mechanism of a free trip. Modern breakers BA series have two types of protection: thermal (executed on a bimetallic plate) designed to protect against long-term current overload and dynamic (also known as electromagnetic performed on an electromagnetic coil), designed to protect against short circuit currents. Contact system consists of fixed contacts mounted on the housing and movable contacts, put on a hinge axis lever control mechanism, and provides, as a rule, a single open circuit. Interrupter device is installed at each pole switch and is intended for localization of the electric arc to a limited extent. Such obsolete machines like AP50 have the same types of protection, but made a much larger form factor. Modern technology certainly allow to perform the circuit-breakers are much smaller (for the same rated current). In the home use machines BA in combination with modern shield is preferable. But in the harsh working conditions with frequent reconnecting cables, overloading the use of machines AP50 and others like him are still reasonable. We are interested primarily in the domestic electrical why dwell on Automata VA. Combined clips from the silver-plated copper and galvanized steel ensure reliable contact with copper and aluminum conductors cross-section from 1 to 25 square meters. mm. BA switches have redesigned control mechanism and the mechanism of a free trip to reduce the effect raspy contact, thus, while turning, contact closure is instantaneous regardless of the speed control knob. Installed a metal plate on the side wall in the NC contacts protects the body from burning. In the manufacture of the body using high quality non-combustible materials with high fire-resistant, shockproof performance and have high mechanical strength. During the assembly of multiple switches, each pole clinch first separately, then the poles are joined together. Terminals, deeply imbedded inside the housing, provide a high degree of safety during accidental contact person to the body of the instrument. Bimetallic plate is connected with the mechanism of a free trip without a backlash, which improves the sensitivity of the device at its bend. Switches are available in one-, two-, three-and four-performance: Two-pole circuit breakers are of general application for protection of power, lighting and other electrical installations. They are designed for manual switching and automatic or manual disconnection of electric consumer under load. Two-pole circuit breakers used performance, usually in DC circuits up to 63 A. mounting block, rail or panel. Pole (phase) circuit breakers are of general application for protection of power, lighting and other electrical installations, as well as motors of emergency conditions, short circuit, overcurrent and undervoltage. They are designed for manual switching and automatic or manual disconnection of electric consumer under load. Execution of a three-pole circuit breakers are used in AC circuits with three-phase load (eg, asynchronous motor with squirrel cage). Trip units can be built in one, two or three poles, depending on the type of machine performance. Four-pole circuit breakers are of general application for protection of power, lighting and other electrical installations, as well as motors of emergency conditions, short circuits and overcurrent. They are designed for manual switching and automatic or manual disconnection of electric consumer under load. Performance of four-pole circuit breakers are used in AC circuits with three-phase load (eg, asynchronous motor with squirrel cage). Trip units can be built in one, two or three poles, depending on the type of machine performance. Own response time switch no more than 0.02 seconds. Operating conditions: ambient temperature shall be within -5 to +40 ° C, and its average value must not exceed + 35 ° C. The switch is mounted on a DIN rail 35 x 7,5 mm. Operating position vertical switches, the designation "Off" up. Before installing the switch, check machine for signs of damage, and make several on and off, make sure that the mechanism is working properly. Check the label on the machine, whether it meets the required conditions. To connect you must use copper conductors (cables) or copper connecting bus. Supply voltage to the conclusions of the switch from the power source is carried out by the findings of 1,3,5,7, ie, above. For installation in switchboards old model, to replace the AU to BA, provided the plastic adapter. Selected automatically switches to the rated current, voltage and operating conditions (based on the type of performance). If you need to choose a machine to connect the known loads to calculate the current. The value of the current rating is determined by the formulas: a) single-phase networks, b) for three-phase networks where: PF - Design capacity is determined by taking into account the ratio of demand (from reference books). Un - nominal voltage, V; cos r - power factor. Characterizes the nature of the load (active or reactive) for incandescent lamps and heaters cos ~ = 1. For motors in the passport indicates the rated power on the motor shaft. Consumed by the engine power of the network will be equal: where: PH - rated power, kW; n - efficiency; Rpotr - power consumption of the network, KW. Based on the current value is selected breaker. Of course the machine has many important parameters, but in everyday life choices can be made based on matching the nominal current and voltage and load connected.