Electrical explosion proof switch disconnect , emergency stop
circuit breaker
Description:
The circuit breaker is generally composed of a contact system, an
arc extinguishing system, an operating mechanism, a trip unit, a
casing, and the like.
When short-circuited, the magnetic field generated by a large
current (generally 10 to 12 times) overcomes the reaction force
spring, the trip unit pulls the operating mechanism, and the switch
instantaneously trips. When overloaded, the current becomes larger,
the heat is increased, and the bimetal is deformed to a certain
extent to push the mechanism (the larger the current, the shorter
the action time).
If there is an electronic type, the current of each phase is
collected by using a transformer, and compared with the set value,
when the current is abnormal, the microprocessor sends a signal to
cause the electronic trip unit to drive the operating mechanism.
The function of the circuit breaker is to cut off and close the
load circuit, and cut off the fault circuit to prevent accidents
from expanding and ensure safe operation. The high-voltage circuit
breaker is to break 1500V, the current is 1500-2000A arc, these
arcs can be extended to 2m and continue to burn without
extinguishing. Therefore, arc extinguishing is a problem that must
be solved by high voltage circuit breakers.
The principle of arc-extinguishing arc is mainly to cool the arc to
attenuate the heat release. On the other hand, the arc is used to
stretch the arc to enhance the recombination and diffusion of the
charged particles, and at the same time, the charged particles in
the arc gap are blown off, and the dielectric strength of the
medium is quickly restored.
Low-voltage circuit breakers, also known as automatic air switches,
can be used to switch the load circuit on and off, as well as to
control motors that are not frequently started. Its function is
equivalent to the sum of all or all of the functions of the knife
switch, over current relay, voltage loss relay, thermal relay and
leakage protector. It is an important protection device in the low
voltage distribution network.
Application:
1. Can be used in hazardous areas: Zone 1 and Zone 2 .
2. Can be used in explosive gas atmospheres of Category IIA and II
B IIC where the temperature classification is T6.
3. Two type of Ex d(IIB) and complex(IIC).
4. Flammable dust atmosphere.
5. Widely using in the fields of oil, chemical industry ,
spaceflight ,war industry and so on.
