Why does the switch not trip, but the main switch trips?

When using electricity at home, you may encounter the situation that the switch at home does not trip when the main switch trips. Of course, the fault is only on the outlet side of the switch. If a fault (such as leakage, short circuit, etc.) occurs between the wiring of the main switch and the switch, it is obvious that the trip of the main switch is normal at this time.

So why is there such a phenomenon of leapfrog tripping?

First of all, one of the simplest reasons is that the rated current of the main switch is less than the rated current of the sub-brake. For example, the rated current of the main switch is C45, while the sub-brake is C63. If the load current is greater than 45 and less than 63, obviously the main switch will trip. And the opening has not yet reached the action condition. However, the probability of this kind of reason is almost zero, because no one will assemble the switch in this way, unless a certain switch is broken, and then someone who doesn't understand just buys a new switch and comes back to install it.

Secondly, there are several reasons that will occur when the main switch of the home is a leakage protector (or other switch with leakage protection function).

1. The main switch is more sensitive than the switch, that is, the leakage current of the main switch is smaller than that of the switch. At this time, even if the rated current of the main switch is larger than that of the switch, the phenomenon of tripping the main switch will also occur.

For example: the leakage action current of the opening is 30mA, but the main switch is 10mA. If a leakage fault occurs on the outlet side of the opening, and the leakage current is less than 30mA but greater than 10mA, it is obvious that the main switch trips but the opening does not.

Products Recommended

Click To View CSQ All AC MCB Types

2. The leakage action time of the main switch is shorter than the leakage action time of the branch or the leakage action time of the two is the same. The former will cause direct tripping of the main switch, while the latter will cause random tripping of the main switch.

The solution is to stagger the leakage action time of the main switch and the opening switch, so that the leakage action time of the main switch is delayed (that is, choose a leakage protection with a delay or a leakage protection with a longer action time), or directly replace the main switch with open.

In addition, sometimes even if the sub-brake has tripped, the main switch will still trip. This may be because a +N type switch is used for opening. Such as 1P+N type, when this switch trips, the neutral line will not be broken. If the zero line leaks, the fault still exists in the line and has not been removed after the opening and tripping, so the main switch may also trip.

To sum up, if the switch in the home has skipping tripping, and the switch is not broken, we can check one by one according to the above reasons. Of course, it is very important that no matter whether it is the main trip or the trip, we must find out the fault point, such as where the leakage point is, or whether there is a short circuit in the line, etc.