Making And Breaking Current Of Circuit Breaker Pdf
File Name: making and breaking current of circuit breaker .zip
- Circuit Breaker Ratings
- Why Making Current of Circuit Breaker is More than Breaking Current?
- Short-Circuit Performance Tests
Circuit Breaker Ratings
Sub-transient period:. The AC current is very large but decays very fast. Transient period:. The current falls at slower rate. Steady-state period:.
In a steady-state period, the current reaches steady value. During sub-transient period, the DC current also present for one to two cycles. The magnitude of the DC current is approximately equal to the peak value of the symmetrical breaking current. How 1. Please anybody tell us. I know 1. I got too much interesting stuff on your blog. I guess I am not the only one having all the enjoyment here!
Keep up the good work. Your email address will not be published. Name required. Email required. Save my name, email, and website in this browser for the next time I comment. What is Making and Breaking Current of Circuit breaker? The circuit breaker is used for switching on and off the circuit and also for isolation of the faulty section in case of the fault. The Making and Breaking Current of circuit breaker both these terms are very important for selection of circuit breaker for any electrical installation.
The making and breaking current capacity parameter of circuit breaker has prime importance when the circuit breaker opens at the time of fault and also when the circuit breaker closes at fault. The braking current capacity of the circuit breaker is the maximum fault current which can flow through the circuit breaker for short period of time from time of occurring short circuit till clearing of the fault without any permanent damage.
The breaking current capacity or short circuit breaking current of the breaker is expressed in KA RMS. The circuit breaker of 40 KA short circuit interrupting capacity can break the 40 KA current without getting damage.
The making current of circuit breaker is the maximum peak value of the current that the breaker can interrupt without any damage if the breaker is closed at fault.
The making current of the circuit breaker is always more than the breaking current. When the fault occur in the electrical network ,the AC and DC current is present. The symmetrical AC components of the fault current is as given below. About The Author Admin. July 19, August 6, Unknown great blog.. April 16, Unknown How 1. June 24, Unknown 1. September 30, Taha I got too much interesting stuff on your blog.
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Why Making Current of Circuit Breaker is More than Breaking Current?
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected. Unlike a fuse , which operates once and then must be replaced, a circuit breaker can be reset either manually or automatically to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect low-current circuits or individual household appliance, up to large switchgear designed to protect high voltage circuits feeding an entire city. The generic function of a circuit breaker, or fuse , as an automatic means of removing power from a faulty system is often abbreviated as OCPD Over Current Protection Device. An early form of circuit breaker was described by Thomas Edison in an patent application, although his commercial power distribution system used fuses. Interconnection of multiple generator sources into an electrical grid required the development of circuit breakers with increasing voltage ratings and increased ability to safely interrupt the increasing short-circuit currents produced by networks.
The rating of the circuit breaker is given on the duties that are performed by it. For complete specification standard ratings and various tests of switches and circuit breakers may be consulted. Apart from the normal working of circuit breakers, the circuit breaker is required to perform following three major duties under short circuit conditions. The rated voltage is depicted in KVrms and used phase to phase voltage for three phase circuit. Standard frequency is 50 Hz.
Short-Circuit Performance Tests
LV switchgear: functions and selection. This is the value of voltage to which the dielectric tests voltage generally greater than 2 Ui and creepage distances are referred to. The maximum value of rated operational voltage must never exceed that of the rated insulation voltage, i. This characteristic expresses, in kV peak of a prescribed form and polarity the value of voltage which the equipment is capable of withstanding without failure, under test conditions.
Switching Equipment pp Cite as. Apart from custom-designed special equipment, the aim is the development of products that will be ultimately submitted to a type-test report in accordance with international and national standards.