What is a isolation switch?

The main function of the general isolation switch is to disconnect small currents and change the operation mode. I don't know if you have found it or not. One of them is to disconnect the small current, which is the problem. When the current reaches a certain level, it may cause damage to the components used for isolation in the isolating switch, making the switch unusable. With this in mind, in order to be able to disconnect large currents, and more importantly, to protect the isolation switch in the face of large currents, it is necessary to provide a fuse (equivalent to a fuse) for protection, so that such isolation The switch is called a fuse disconnector.

To put it more professionally, it can be defined as follows: a fuse-type isolating switch needs to meet the following three points:

1. Protect the switch by using a fuse

2. Under normal circuit conditions (including specified overload), it can make, carry and break current, and under specified abnormal circuit conditions (such as short circuit) and within a specified time, it can carry current.

3. It can provide safe isolation for the circuit, and when in the opening position, it can ensure that the circuit is disconnected and ensure safe work.

Then add some notes about the fuse disconnector. Generally speaking, this type of isolating switch is mainly used for conventional lines for protection. It is generally not used as a motor switch, because the breakdown current of the motor when starting and stopping is too large, which is very easy to cause damage to the fuse disconnector. Again, even for the same type of switch, when the rated heating current of the switch is different, the fuses used are not the same, for example, for the HR6 fuse-type isolating switch mentioned at the beginning of the article. When the rated current is 100A, the selected fuse link is NT00, and when the current is 250A, the selected fuse link should be NT1. For this, we need to pay more attention when we purchase fuse-type isolating switch, and choose the appropriate model according to our own situation, so as to avoid unnecessary trouble.
The above is my personal understanding of fuse-type isolating switches, mainly including and different from ordinary isolating switches, the definition of common models, and the places that need to be paid more attention when purchasing