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What is the Electrical circuit breaker making and making capacity?
making current is a peak value attain at first cycle when the circuit breaker is close.the making current rating is expressed in "peak" value of the maximum ac current it can safely close on that's why it is always have higher value than breaking current. Making current is limited by the withstand capability of the contacts. Breaking current is based on the ability of the contacts to interrupt the current. If the contacts are not able to interrupt the current when they open, the heat energy in the resulting arc will often destroy the device. the breaking current rating is expressed in RMS value of the current.
What is difference between vacuum circuit breaker and vacuum contactor?
First thing, there is nothing like vacuum circuit contactor. It is a vacuum contactor. It has hrc fuse for protection against short circuit and have vacuum bottles in which contacts move to get close and open. It will never trip bcas it does not have tripping mechanism, it does not have operating mechanism. It's contacts are made only to make and break normal current. It is used to start and stop a motor only. It does not have ka rating for fault current. Vacuum circuit breaker is a real fault current breaker which trips during a fault like short circuit, earth fault, under or over voltage or any one. It encompasses the operating mechanism to break the contacts at a very high speed and also need a spring charging mechanism to turn the breaker on. It has very highly rated contacts inside a heavy capacity vacuum bottles. It has realese ( something like solenoid ) which pulls the plunger after it get signals from various protection relays in case of fault. It is not meant to operate for day to day start and stop operation of motor. It has ka rating for fault current. Analogus to ordinary home circuit, vcb is like a circuit breaker at home inside a panel and vc is a relay in our any of instruments at home. Analogus to low voltage situation, vcb is like a fault current ( air, or bulk oil or minimum oil ) circut breaker and vc is like an ordinary contactor
What is the 'short circuit capacity' of a 32A 60898 MCB?
Depends on manufacturer..Normally the ratings are as follows 1. Service short circuit breaking capacity is 7.5 kA 2. Rated short circuit breaking capacity is 10 kA.
How do you calculate kA for breaker?
It has been some time but here goes. The circuit breaker size can be found when some other information is given. For a given voltage value, the size of the cb is basically found using the formula P(Kw) = IV here the value of I is approx the value of the circuit breaker. The solution is not so simple since there are normally tolerances set by the different regulator organisations as to these values. Another situation to consider is the type of current and voltage you are using ie ac or dc, Vac or Vdc. also the amount of phases if it is ac voltages we are considering . If 3 phase ac voltage and current the formula used is as follows P(kva) = 1.73 x IL x VL x pf where pf , the power factor is the introduced and kva the apparent power is used instead of kw here because under most conditions a power factor of 1 cannot be achieved. IL and VL are the line current and voltage. Gladstone
Busbar fault level calculation?
what do you mean by 50 KA for 1 sec
