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.

運行短路分斷能力Ics——在規定的試驗程序和試驗參數下，電器能接通和分斷的短路電流能力。試后還具有一定的介電耐壓能力，并且須考慮繼續承栽它的額定電流。

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.

短時耐受電流Icw——在規定的試驗條件下，斷路器能承載而不損壞的短時耐受電流值。短時耐受電流Icw只適用于具有短路短延時特性的電器。

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.額定電流在600A以下，且短路電流不大時，可選用塑殼斷路器；額定電流較大，短路電流亦較大時，應選用萬能式斷路器。

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.

一般選用原則為： (1)斷路器額定電流≥負載工作電流；

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

(2)斷路器額定電壓≥電源和負載的額定電壓；

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

(3)斷路器脫扣器額定電流≥負載工作電流；

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

(4)斷路器極限通斷能力≥電路最大短路電流；

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

(5)線路末端單相對地短路電流/斷路器瞬時(或短路時)脫扣器整定電流≥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)斷路器欠電壓脫扣器額定電壓=線路額定電壓。

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

3.斷路器的短路分斷能力≥線路的預期短路電流。斷路器的短路分斷能力通常是指它的極限短路分斷能力。斷路器有三個重要的短路電流分段能力指標，分別為：極限短路分斷能力(Icu)、運行短路分斷能力(Ics)和短時耐受電流(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).

國內低壓斷路器的運行短路分斷能力Ics絕大多數是小于它的極限短路分斷能力Icu的。我國國家標準GB140482規定，Ics可以是Icu數值的25%、50%、75%和100%。設計人員在設計選用時只要符合斷路器的極限短路分斷能力≥線路預期短路電流就能滿足要求了，有些設計者認定要按斷路器的運行短路分斷能力(Ics)≥線路預期短路電流來設計，其實是一種誤解，也是不必要的.所以在選擇時應先選用Ics值。達到Icu極限值，斷路器可能被損壞，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.