Functions of main and auxiliary contacts of molded case circuit breaker:

1、辅助触点起到传达断路器的工作状态信号的一个作用。为控制回路提供互锁接点；为信号回路提供断路器的分合位置状态；为保护回路提高跳闸接点；

1. The auxiliary contact plays a role in transmitting the working state signal of the circuit breaker. Provide interlocking contact for control circuit; Provide the opening and closing position status of the circuit breaker for the signal circuit; Improve the tripping contact for the protection circuit;

2、辅助触点与主触点是同时动作的，是机械结构关系，扳主触点的同时有内部机构带动辅助触点同步动作。辅助触点通常是一个常开加一个常闭结构：主触点闭合则辅助触点常开触点闭合，常闭触点断开；主触点断开则常开触点断开，常闭触点闭合。

2. The auxiliary contact and the main contact act at the same time, which is a mechanical structure relationship. When pulling the main contact, there is an internal mechanism to drive the auxiliary contact to act synchronously. The auxiliary contact is usually a normally open plus a normally closed structure: when the main contact is closed, the normally open contact of the auxiliary contact is closed and the normally closed contact is open; When the main contact is open, the normally open contact is open and the normally closed contact is closed.

那么，如何判断塑壳断路器触点接触的好坏呢？

So, how to judge the contact quality of molded case circuit breaker?

1、在选择断路器的时候要根据电流的等级进行选定，一般情况下，选定后就不会出现图片所示的情况；

1. The circuit breaker shall be selected according to the current level. Generally, the situation shown in the picture will not appear after selection;

塑壳断路器触点打火，引燃了上方的控制线槽

The contacts of the molded case circuit breaker ignited and ignited the control trunking above

2、检查触点接触的好坏，还是拆开来检查比较稳妥。之前用过一种方法，就是在设备送电正常运行的时候，用非接触式的测温枪进行温度检测，对每相靠近触点的位置进行检测，对温度值进行比较；

2. Check whether the contact is good or bad, or it is safer to take it apart. A method has been used before, that is, when the equipment is powered on and running normally, use a non-contact temperature measuring gun to detect the temperature, detect the position of each phase close to the contact, and compare the temperature values;

3、检查产品是不是哪个地方接触不好，接触不好肯定温度会升高，引起自燃的情况；

3. Check whether the product is in bad contact. If it is in bad contact, the temperature will rise and cause spontaneous combustion;

注：以上的检查情况，是根据多次事故发生的经验，总结出来的可能会造成这种现象的原因，但实际情况是触头的阻值受环境影响变化很大，比如温度湿度以及灰尘都会影响到触头的阻值，因此无法通过一个标准阻值来衡量触点是否已损坏。

Note: the above inspection conditions are summarized based on the experience of many accidents, which may cause this phenomenon, but the actual situation is that the resistance value of the contact changes greatly affected by the environment, such as temperature, humidity and dust will affect the resistance value of the contact, so it is impossible to measure whether the contact has been damaged by a standard resistance value.