This article is mainly about the introduction of three-phase circuit breakers, and focuses on the model specifications and parameter characteristics of the three-phase circuit breakers.
Three-phase circuit breakerA three-phase circuit breaker is a kind of switching device, which is mainly developed to prevent abnormal current or voltage from occurring. The three-phase circuit breaker guarantees the safe use of electricity to a large extent. Three-phase circuit breakers are generally divided into high-voltage and low-voltage circuit breakers. Regardless of whether it is high-voltage or low-voltage, three-phase circuit breakers have different models, and the performance varies according to the model. So what are the models and specifications of the best three-phase circuit breakers on the market? Next, let us understand
Three-phase circuit breaker modelLong March MA40 series frame type circuit breaker
Features: the originator of the domestic DW45 series products, unparalleled industry experience; industry-leading short-circuit breaking capacity, zero arcing distance; advanced micro-processing technology intelligent controller, perfect intelligent protection function; high and low temperature impact test, salt test , EMC test, vibration and damp heat test, stable and reliable. Features of Long March MB30 series molded case circuit breakers: small size, high breaking capacity, special arc extinguishing devices for products with three breaking capacities of S, M, and H, short arcing distance, modular structure design, easy installation and maintenance; yes A variety of accessories can be selected to meet the needs of different occasions. The shell is made of recyclable plastic, which is energy-saving and environmentally friendly, light in weight, high in insulation strength, and safe and reliable in operation and breaking.
Long March MB1 series miniature circuit breaker
Scope of application
The series of miniature circuit breakers have the characteristics of advanced and reasonable structure, reliable performance, high breaking capacity, beautiful and compact appearance, etc. The shell and other parts are made of impact-resistant and highly flame-retardant materials. Suitable for AC 50Hz or 60Hz, rated current 6A to 125A occasions. It is mainly used for lighting, power distribution lines and equipment overload and short-circuit protection of office buildings, residences and similar buildings. It can also be used for infrequent line switching under normal circumstances.
Three-phase circuit breaker specificationsGenerally used in power, three-phase motor air circuit breakers, you can choose D65 N-XXXX. C65N series S7L1600, PR211I, R1600, FHR, S7L1600. The air circuit breaker uses air or air flow as the arc extinguishing medium. When the circuit breaker breaks the current, an arc will be generated between the two contacts that are opened. The electromagnetic force generated by the arc current is used in the design. The arc is stretched into the arc extinguishing grid, so that the arc is rapidly cooled and the arc is extinguished. Three-phase circuit breaker working conditions Ambient air temperature: upper limit of ambient air temperature + 40°C lower limit of surrounding air temperature-5°C ambient air temperature
The average temperature of 24h does not exceed +35°C.
Altitude: The altitude of the installation site does not exceed 2000m
Atmospheric conditions: the relative humidity of the atmosphere does not exceed 50% when the ambient air temperature is +40°. The relative humidity can be higher at a lower temperature. The average monthly maximum relative humidity of the wettest month is 90%, and the monthly average of the month The lowest temperature is +25℃, taking into account the condensation on the surface of the product due to temperature changes
Pollution degree: Pollution degree is 3
According to different models and specifications, three-phase circuit breakers have different uses. Three-phase circuit breakers can be widely used in industry, commerce, agriculture and even daily production and life. But we usually don't look at high-voltage circuit breakers. We usually use low-voltage circuit breakers. Then we can choose frame-type three-phase circuit breakers. This circuit breaker is more suitable for use in production and life. In addition to other types of circuit breakers, most of them are used in industrial production.
Using power/voltage equals current. For example, the total power of electrical appliances is 4KW, then 4000/220=18A.
The rated current of the air switch is required to be greater than the load current.
Under normal circumstances, the choice of air switch is calculated by 1.5 times the load current, 18A*1.5=27A. There is no 27A air switch, so
The air switch should be 32A.
The three-phase electricity is calculated as follows
Power = current * voltage * root number 3 * power factor
Current = power / voltage / root number 3 / power factor
For example, the load is 6KW, then the current=6000/380/1.732/0.85=10.7A.
Choosing a circuit breaker requires that the rated current of the circuit breaker is greater than the load current.
ConclusionThis is the end of the relevant introduction about three-phase circuit breakers. I hope this article will give you a deeper understanding of three-phase circuit breakers.
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