Frame circuit breakers have a wide range of intelligent protection functions to provide selective protection, accurate operation, prevent unnecessary power outages and improve power supply reliability. Under normal conditions, it can be used as a frequent changeover of circuits. One of the low-voltage frame circuit breakers has rated voltages of 380V, 660 and 690V and rated currents of 200A-6300A, and is mainly used for power distribution to protect line and power supply equipment from overload, low voltage, short circuit and single phase earth faults.

In addition, there are two types of low-voltage frame circuit breakers with short-circuit capacity. One is the ultimate short-circuit interception capacity Icu, the other is the short-circuit interception capacity Ics, IcsIcu. In addition, the circuit breaker has a short-time withstand current Icw.

(1) Ultimate short-circuit interception capacity

For voltage, short-circuit current, power factor and other specific experimental parameters (such as voltage, short-circuit current, power factor conditions), is the short-circuit current that can be connected and disconnected after a specific experimental procedure, this connection is disconnected and no longer transmits the rated current blocking capacity. It has a test procedure of 0-T (online) C0, after which the desorption characteristics and the frequency internal pressure are verified.

' 0 ' means rest, ' t ' means intermittent time, usually 3 min, ' c0 ' means interruption immediately after connection

(2) Short-circuit break function operation

It also means that under specific experimental parameter conditions and after a specific experimental procedure, it can continue to carry the short-circuit current of connection and disconnection, and afterwards also continue to carry the separation capacity of the rated current. The experimental procedure is 0-T (online) C0-T (online) C0.

(3) Short-time withstand current (Icw)

is the ability to withstand 0.05, 0.1, 0.25, 0.5 or 1s under a certain voltage, short-circuit current, power factor, the circuit breaker does not allow deductions. icw is an evaluation indicator of the electrical and thermal stability of the circuit breaker during a short delayed trip.

The above content is provided by the frame circuit breaker manufacturer Rui Rui Electrical finishing.