In the selection of ABB miniature circuit breaker, low-voltage circuit breaker and leakage circuit breaker account for a large share, so it is very necessary to understand some selection principles. This paper will introduce the selection principles of these two circuit breakers in detail.

一、ABB微型斷路器的選用

1、 Selection of ABB miniature circuit breaker

ABB微型斷路器的選用，應根據具體使用條件選擇使用類別，選擇額定工作電壓、額定電流、脫扣器整定電流和分勵、欠壓脫扣器的電壓電流等參數，參照產品樣本提供的保護特性曲線選用保護特性，并需對短路特性和靈敏系數進行校驗。當與另外的斷路器或其他保護電器之間有配合要求時，應選用選擇型斷路器。作為例子，用DZ20斷路器作參考。

For the selection of ABB miniature circuit breaker, the use category shall be selected according to the specific use conditions, and the parameters such as rated working voltage, rated current, setting current of release, voltage and current of shunt and undervoltage release shall be selected. The protection characteristics shall be selected with reference to the protection characteristic curve provided by the product sample, and the short-circuit characteristics and sensitivity coefficient shall be verified. When there are coordination requirements with other circuit breakers or other protective appliances, selective circuit breakers shall be selected. As an example, DZ20 circuit breaker is used as a reference.

1.額定工作電壓流和額定電壓 低壓斷路器的額定工作電壓Ue和額定電流Ie。應分別不低于線路，設備的正常額定工作電壓和工作電流或計算電流。斷路器的額定工作電壓與通斷能力及使用類別有關，同一臺斷路器產品可以有幾個額定工作電壓和相對應的通斷能力及使用類別。

1. Rated working voltage current and rated voltage rated working voltage Ue and rated current ie of low-voltage circuit breaker. It shall not be lower than the normal rated working voltage and working current or calculated current of the line and equipment respectively. The rated working voltage of the circuit breaker is related to the making and breaking capacity and use category. The same circuit breaker product can have several rated working voltages and corresponding making and breaking capacity and use category.

2.長延時脫扣器整定電流Ir1 所選斷路器的長延時脫扣器整定電流Ir1；應大于或等于線路的計算負載電流，可按計算負載電流的1-1.1倍確定；同時應不大于線路導體長期允許電流的0.8-1倍。

2. Setting current IR1 of long time delay release setting current IR1 of the selected circuit breaker; It shall be greater than or equal to the calculated load current of the line, which can be determined by 1-1.1 times of the calculated load current; At the same time, it shall not be greater than 0.8-1 times of the long-term allowable current of the line conductor.

3.瞬時或短延時脫扣器的整定電流Ir2 所選斷路器的瞬時或短延時脫扣器整定電流Ir2應大于線路尖峰電流。配電斷路器可按不低于尖峰電流1.35倍的原則確定，電動機保護電路當動作時間大于0.002s 時可按不低于1.35倍起動電流的原則確定，如果動作時間小于0.02s，則應增加為不低于起動電流的1.7-2倍。這些系數是考慮到整定誤差和電動機起動電流可能變化等因素而加的。

3. The setting current IR2 of the instantaneous or short delay release of the selected circuit breaker shall be greater than the line peak current. The distribution circuit breaker can be determined according to the principle of not less than 1.35 times of peak current. When the action time of motor protection circuit is greater than 0.002s, it can be determined according to the principle of not less than 1.35 times of starting current. If the action time is less than 0.02s, it should be increased to not less than 1.7-2 times of starting current. These coefficients are added considering the setting error and the possible change of motor starting current.

4.短路通斷能力和短時耐受能力校驗 低壓斷路器的額定短路分斷能力和額定短路接通能力應不低于其安裝位置上的預期短路電流。當動作時間大于0.0.2s時，可不考慮短路電流的非周期分量，即把短路電流周期分量有效值作為最大短路電流；當動作時間小于0.02s時，應考慮非周期分量，即把短路電流第一周期內的全電流作為最大短路電流。如校驗結果說明斷路器通斷能力不夠，應采取如下措施。

4. Short circuit making and breaking capacity and short-time withstand capacity verification the rated short-circuit breaking capacity and rated short-circuit making capacity of low-voltage circuit breaker shall not be lower than the expected short-circuit current at its installation position. When the action time is greater than 0.0.2s, the aperiodic component of short-circuit current can be ignored, that is, the effective value of periodic component of short-circuit current can be taken as the maximum short-circuit current; When the action time is less than 0.02s, the aperiodic component shall be considered, that is, the full current in the first cycle of short-circuit current shall be taken as the maximum short-circuit current. If the verification results show that the on-off capacity of the circuit breaker is insufficient, the following measures shall be taken.

1）在斷路器的電源側增設其他保護電器（如熔斷器〕作為后備保護。

1) Add other protective appliances (such as fuses) at the power side of the circuit breaker as backup protection.

2）采用限流型斷路器，可按制造廠提供的允通電流特性或限流系數（即實際分斷電流峰值和預期短路電流峰值之比）選擇相應的產品。

2) The current limiting circuit breaker can be selected according to the allowable current characteristics or current limiting coefficient (i.e. the ratio of the actual breaking current peak to the expected short-circuit current peak) provided by the manufacturer.

3）時改選較大容量的斷路器。各種短路保護斷路器必須能在閉合位置上承載未受限制的短路電流瞬態值，還須能在規定的延時范圍內承載短路電流。這種短時承載的短路電流值應不超過斷路器的額定短時耐受能力，否則也應采取措施或改變斷路器規格。斷路器產品樣本中一般都給出產品的額定峰值耐受電流和額定短時耐受電流（Is電流）。當為交流電流時，短時耐受電流應以未受限制的短路電流周期分量的有效值為準。

3) The circuit breaker with larger capacity shall be selected when. Various short-circuit protection circuit breakers must be able to carry unrestricted short-circuit current transient value in the closed position and short-circuit current within the specified time delay range. The short-circuit current value of this short-time load shall not exceed the rated short-time withstand capacity of the circuit breaker, otherwise measures shall be taken or the specification of the circuit breaker shall be changed. The rated peak withstand current and rated short-time withstand current (is current) of the product are generally given in the product sample of circuit breaker. In case of AC current, the short-time withstand current shall be subject to the effective value of unrestricted short-circuit current periodic component.

二、漏電斷路器的選用

2、 Selection of leakage circuit breaker

漏電斷路器具有兩個功能，一是具有斷路器的功能，二是具有漏電保護的功能。斷路器功能與一般低壓斷路器相同，漏電保護部分通過零序互感器檢測的是剩余電流，即通過檢測被保護回路內相線和中性線的電流瞬時值，判斷對地泄漏電流的變化。因此，斷路器，如常見的DZ47LE漏電斷路器功能部分的選擇與一般低壓斷路器相同。漏電保護功能部分（下稱漏電保護器）的選擇應考慮兩個基本條件，一是漏電保護器的漏電動作電流必須躲過電網正常泄漏電流，二是漏電保護器的漏電動作電流必須小于引起火災的最小點燃電流或人體安全電流，按選用漏電保護器的主要目的確定。一般按以下原則選擇。

The leakage circuit breaker has two functions: one is the function of circuit breaker, and the other is the function of leakage protection. The function of the circuit breaker is the same as that of the general low-voltage circuit breaker. The leakage protection part detects the residual current through the zero sequence transformer, that is, judge the change of the leakage current to the ground by detecting the instantaneous current value of the phase line and neutral line in the protected circuit. Therefore, the selection of the functional part of the circuit breaker, such as the common dz47le leakage circuit breaker, is the same as that of the general low-voltage circuit breaker. The selection of leakage protection function part (hereinafter referred to as leakage protector) shall consider two basic conditions: one is that the leakage action current of leakage protector must avoid the normal leakage current of power grid; the other is that the leakage action current of leakage protector must be less than the minimum ignition current or human safety current causing fire, which shall be determined according to the main purpose of selecting leakage protector. Generally, it is selected according to the following principles.

（1）選擇漏電保護器的額定動作電流按國家標準GB13955-92《漏電保護器安裝和運行》的規定，選擇漏電保護器的額定動作電流應根據電氣線路的正常泄漏電流確定，并應充分考慮到被保護線路和設備可能發生的正常泄漏電流值，必要時可通過實際測量取得被保護線路和設備的泄漏電流值。

(1) The rated operating current of the leakage protector shall be selected according to the provisions of the national standard gb13955-92 installation and operation of leakage protector. The rated operating current of the leakage protector shall be determined according to the normal leakage current of the electrical line, and the possible normal leakage current of the protected line and equipment shall be fully considered, If necessary, the leakage current value of the protected line and equipment can be obtained through actual measurement.

（2）選擇漏電保護器的額定漏電不動作電流按國家標準《漏電保護器安裝和運行》的規定，漏電保護器的額定漏電不動作電流應不小于電氣線路和設備的正常泄漏電流的最大值的2倍。

(2) Select the rated leakage non action current of the leakage protector. According to the provisions of the national standard installation and operation of leakage protector, the rated leakage non action current of the leakage protector shall not be less than twice the maximum value of the normal leakage current of electrical lines and equipment.

（3）電氣線路和設備泄漏電流值與分級安裝的漏電保護特性的配合

(3) Coordination between leakage current value of electrical lines and equipment and leakage protection characteristics of graded installation

1）用于單臺用電設備時，漏電保護器動作電流應不小于正常運行實測泄漏電流的4倍。以防止因漏電引起觸電事故和火災。

1) When used for single electrical equipment, the action current of leakage protector shall not be less than 4 times of the measured leakage current in normal operation. To prevent electric shock and fire caused by electric leakage.

2）配電線路的漏電保護器動作電流應不小于正常運行實測泄漏電流的2.5 倍，同時還應滿足其中泄漏電流最大的一臺用電設備正常運行泄漏電流的4 倍。以防止因漏電引起火災。

2) The action current of the leakage protector of the distribution line shall not be less than 2.5 times of the measured leakage current in normal operation, and shall also meet 4 times of the normal operation leakage current of the electric equipment with the largest leakage current. To prevent fire caused by electric leakage.

3）用于全網保護時，動作電流應不小于實測泄漏電流的2倍。為全網增設全面的漏電保護，防止因漏電引起火災。

3) When used for the whole network protection, the action current shall not be less than 2 times of the measured leakage current. Add comprehensive leakage protection for the whole network to prevent fire caused by leakage.

（4）一般地，不同額定剩余動作電流的漏電保護器可按以下原則選用。如常用型號：DZ47LE-32

(4) Generally, leakage protectors with different rated residual operating current can be selected according to the following principles. For example, common model: DZ47LE-32

1）額定剩余動作電流為30mA及以下的漏電保護器，用于對直接接觸及TT系統的保護；及不直接接觸、IT中性線不接地系統和完全暴露條件（如建筑工地、游泳池、娛樂場所等）的保護。

1) Leakage protector with rated residual operating current of 30mA and below is used to protect direct contact and TT system; And the protection of non direct contact, it neutral ungrounded system and completely exposed conditions (such as construction sites, swimming pools, entertainment places, etc.).

2）額定剩余動作電流為50mA及以上的漏電保護器，用于對非直接接觸及TT系統及防止火災的保護。

2) Leakage protector with rated residual operating current of 50mA and above is used to protect indirect contact and TT system and prevent fire.

3）配置選擇性保護時應保證除對非直接接觸及TT系統可保護外，還能對下級裝有30mA的漏電保護系統作選擇性保護。僅隔離事故電路，其它電路仍應保證繼續供電。

3) When configuring selective protection, it shall be ensured that in addition to the protection of indirect contact and TT system, it can also provide selective protection for the lower level leakage protection system equipped with 30mA. Only isolate the accident circuit, and other circuits shall still ensure continuous power supply.

以上就是關于ABB微型斷路器和漏電斷路器選型中需要注意的原則，相信對大家能有所幫助！

The above is about the principles that should be paid attention to in the selection of ABB miniature circuit breaker and leakage circuit breaker. I believe it can be helpful to you!