ABB miniature circuit breaker price / agent to explain to you what is the maximum current?

1. Limit short-circuit breaking capacity ICU - the short-circuit current capacity that the electrical apparatus can make and break under the specified test procedures and test parameters. [] After the test, it also has a certain dielectric withstand voltage capacity, but its rated current can not be considered.

运行短路分断能力Ics——在规定的试验程序和试验参数下，电器能接通和分断的短路电流能力。试后还具有一定的介电耐压能力，并且须考虑继续承栽它的额定电流。

Operating short-circuit breaking capacity ICs - the short-circuit current capacity that the appliance can make and break under the specified test procedures and test parameters. After the test, it also has a certain dielectric withstand voltage capacity, and its rated current must be considered to continue to be planted.

短时耐受电流Icw——在规定的试验条件下，断路器能承载而不损坏的短时耐受电流值。短时耐受电流Icw只适用于具有短路短延时特性的电器。

Short time withstand current ICW - the short-time withstand current value that the circuit breaker can carry without damage under the specified test conditions. The short-time withstand current ICW is only applicable to electrical appliances with short-circuit short-time delay characteristics.

2.额定电流在600A以下，且短路电流不大时，可选用塑壳断路器；额定电流较大，短路电流亦较大时，应选用式断路器。

2. When the rated current is below 600A and the short-circuit current is small, the molded case circuit breaker can be selected; When the rated current is large and the short-circuit current is also large, the universal circuit breaker shall be selected.

一般选用原则为： (1)断路器额定电流≥负载工作电流；

General selection principles are as follows: (1) rated current of circuit breaker ≥ load working current;

(2)断路器额定电压≥电源和负载的额定电压；

(2) Rated voltage of circuit breaker ≥ rated voltage of power supply and load;

(3)断路器脱扣器额定电流≥负载工作电流；

(3) Rated current of circuit breaker release ≥ load working current;

(4)断路器极限通断能力≥电路短路电流；

(4) The limit making and breaking capacity of the circuit breaker ≥ the maximum short-circuit current of the circuit;

(5)线路末端单相对地短路电流/断路器瞬时(或短路时)脱扣器整定电流≥1.25；

(5) Single phase to ground short-circuit current at the end of the line / instantaneous (or short-circuit) release setting current of the circuit breaker ≥ 1.25;

(6)断路器欠电压脱扣器额定电压=线路额定电压。

(6) Rated voltage of circuit breaker undervoltage release = rated voltage of line.

3.断路器的短路分断能力≥线路的预期短路电流。断路器的短路分断能力通常是指它的极限短路分断能力。断路器有三个重要的短路电流分段能力指标，分别为：极限短路分断能力(Icu)、运行短路分断能力(Ics)和短时耐受电流(Icw)。

3. The short-circuit breaking capacity of the circuit breaker is ≥ the expected short-circuit current of the line. The short-circuit breaking capacity of circuit breaker usually refers to its limit short-circuit breaking capacity. The circuit breaker has three important short-circuit current sectioning capacity indicators, namely: limit short-circuit breaking capacity (ICU), operating short-circuit breaking capacity (ICS) and short-time withstand current (ICW).

国内低压断路器的运行短路分断能力Ics绝大多数是小于它的极限短路分断能力Icu的。我国标准GB140482规定，Ics可以是Icu数值的25%、50%、75%和100%。设计人员在设计选用时只要符合断路器的极限短路分断能力≥线路预期短路电流就能满足要求了，有些设计者认定要按断路器的运行短路分断能力(Ics)≥线路预期短路电流来设计，其实是一种误解，也是不必要的.所以在选择时应先选用Ics值。达到Icu极限值，断路器可能被损坏，不能使用了。

The operating short-circuit breaking capacity ics of domestic low-voltage circuit breakers is mostly less than its limit short-circuit breaking capacity ICU. China's national standard gb140482 stipulates that ICs can be 25%, 50%, 75% and 100% of ICU value. When designing and selecting, designers can meet the requirements as long as they meet the limit short-circuit breaking capacity of the circuit breaker ≥ the expected short-circuit current of the line. Some designers believe that it is a misunderstanding and unnecessary to design according to the operating short-circuit breaking capacity (ICS) ≥ the expected short-circuit current of the line Therefore, the ICs value should be selected first. If the ICU limit value is reached, the circuit breaker may be damaged and cannot be used.