The air switch is a switch that automatically turns off as long as the current in the circuit is too large. The relevant indicators of the air switch can be obtained from the model.

Examples of relevant models are as follows:
1) DZ20-100/320 Ie=60A
 DZ--"Automatic" anti-pinyin  20-- design number  100- is its shell level  3--- represents the number of poles that are three-phase  2 --- tripping mode (0-- no off Fasteners, 1--thermal release, 2-electromagnetic release, 3-fold
 0---With or without auxiliary contacts (0--without auxiliary contacts, 2- with auxiliary contacts)
 Ie=60A---Over current regulation rated current.
Wherein the rated voltage of the air switch is greater than or equal to the rated voltage of the line, and the rated current of the air switch rated current and the overcurrent release is greater than or equal to the calculated load current of the line.

2) DZ47-60A C25
DZ47---Series miniature circuit breakers ----- LE-----with leakage trip function 60-----Frame grade is 60A
 C------ instantaneous trip overcurrent multiple, for lighting (5~7 or 7~10 times), D for power (10~14 times)
 25----- rated current