The difference between air switch and knife switch

By：Nader Updated：September 09,2020 11:52AM

We often see electric bus switches for rural households including air switches and knife switches. Knife switches are not common in urban households, but they are still very common in rural households. However, in recent years, knife switches have gradually decreased and gradually replaced by air switches. Two kinds of switches have their own advantages, so should you choose one when choosing a switch?

Knife switch external structure

Knife switch internal structure

Knife switch external structure

The above kind of switch is a knife switch often used in the family. In addition to the separation function, it also has an overcurrent blown fuse (sheet). This kind of switch has been used by most families because of its simplicity and low price. .

air switch

Air switch is also called air circuit breaker, and it is also a kind of switch, but this kind of switch has the function of extinguishing arc in addition to the function of separating circuit and overcurrent fuse of knife switch. What is arc extinguishing? Extinguishing an arc means extinguishing an arc. Arc is the electric spark we see when we close or open the switch. Electric spark is a relatively slight discharge phenomenon in electric arc. Because this air switch has an arc extinguishing function, no electric spark can be seen when the switch is closed or opened, so its safety is better than that of a knife switch.

So should I choose a knife switch or an air switch? It depends on the situation

First of all, knife switch and air switch have their own advantages and disadvantages:

Comparison of advantages and disadvantages of knife switch and air switch

	Switch knife	Air switch
Advantage	a. Low price b. Can clearly see the breakpoint of the circuit	a. With arc extinguishing capability, high safety b. After the circuit is disconnected, it is not necessary to replace the originals when closing, and the reuse rate is high
Disadvantage	No arc extinguishing function, easy to see electric sparks, and the fuse needs to be replaced	The price is more expensive, the service life is shorter than the knife switch

So, which switch you use depends on which effect you want. If you want to be able to see the obvious disconnection point of the circuit (can clearly see the disconnection point, people are more relieved) choose the knife switch. After all, the disconnection point cannot be seen after the air switch is disconnected. As for the disconnection, it depends on Whether the air switch is in the normal state; if you want a higher safety and can extinguish the arc, then choose the air switch

Tags: air switch