0
The previous answer is incorrect, and I would advise that user to not give out information if they are going to give completely misguided information. The interrupting rating of a breaker is the maximum current that the breaker is designed to handle, at the breaker's rated voltage, before damage will occur to the breaker. A breaker will trip at FAR LESS than the interrupting rating, but it is extremely dangerous to expose the breaker to any situation where it will have more than the rated interruption current. the breaker is designed for. The reason some breakers are rated at 22kA instead of 10kA is because they typically have far larger conductors hooked up to them, so with the lowered impedance on the circuit there is more of a chance for the breaker to experience a higher fault current at the breaker. So electricians install 22kA breakers to handle the higher "available fault current."
Circuit breakers are designed based on voltage and current ratings required. The circuit breaker opens by an electromagnetic action though the control circuit might be digital or analog. For a 10KA circuit breaker if the current in the circuit exceeds 10KA then a control signal will be given to the circuit breaker then by electromagnetic action the circuit breaker opens the circuit. So a 10KA circuit breaker opens the circuit when current in that circuit is greater than 10KA, in the same way a 22KA circuit breaker opens the circuit when the current in that circuit is more than 22KA. For example the circuit breaker is controlled by a digital circuit. The current in the circuit is measured continuously and compared with the rating of the circuit breaker, for example if it is a 10KA circuit breaker then the current measurement is compared with the 10KA and if the measurement in the circuit is more than 10KA then the control signal will be sent to electromagnetic circuit to open the circuit breaker.
Add your answer:
Earn +20 pts
What is the rated short circuit capacity of the miniature circuit breaker used?
Breaking Current: The r.m.s value of short circuit current at the instant of contact separation.
Difference between fuse and mcb?
CB MCB (i) Mechanism of CB is tripping relay. (i) Mechanism of MCB is tripping release (ii) It is used in HV system. (ii) It is used in LV system. (iii) Rupturing capacity is high . (iii) Rupturing capacity is low.
What is 10kA in circuit breakers?
10,000 Amperes.
What is the rated short circuit capacity of the miniature circuit breaker used?
Breaking Current: The r.m.s value of short circuit current at the instant of contact separation.
Difference between fuse and mcb?
CB MCB (i) Mechanism of CB is tripping relay. (i) Mechanism of MCB is tripping release (ii) It is used in HV system. (ii) It is used in LV system. (iii) Rupturing capacity is high . (iii) Rupturing capacity is low.
What does the stamp 10kA on a ring mean?
It is the carrot reading with an alloy added to it
What is the reason for using a 10kA breaker rather than a 6kA in simplest possible way possibly with an example?
Breakers are designed to open when there is too much current. For instance, if you have a 100A breaker and you put a 120A load on it, it trips.But what if you drop a wrench or piece of pipe across the wires? Much more than 100A will flow, usually thousands of amps. This is fault current. If the current is too high, the breaker can weld itself closed and fail to trip. This would be very bad.So, breakers have an interrupt rating. It indicates how much fault current the breaker can safely handle and still operate properly. Your 6000A or 10000A is the interrupt rating.You would need a 10000A breaker instead of a 6000A breaker if the fault current could be in excess of 6000A, but less than 10000A.How much fault current can flow in a given situation? It depends on how heavy-duty the utility distribution transformer is, and how big the supply wires are. The utility company can usually supply the information which an electrical engineer can use to calculate the interrupt rating needed. The whole panel, not just the breaker, must carry the same or higher interrupt rating.
Was a wave of nationalism in the US following the War of 1812?
Yes, in fact there was such an increase in national pride that it formed a sort of unity between most Americans of the time. Rituals of celebration on occasion such as Washington's birthday and the Fourth of July also helped to unify the country.
What are the types of grounding?
1. Ungrounded. Electrical power systems that are operated with no intentional connection to earth ground are described as ungrounded. Although these systems were standard in the '40s and '50s, they're still in use today. The main advantage of this type of grounding system is that it offers a low value of current flow and reliability during a fault. Unfortunately, this type of system also offers some big disadvantages. One major disadvantage to an ungrounded system is in the difficulty in locating a line-to-ground fault. Finding the fault is a time consuming process. For that reason, it's often done on the weekends so a company doesn't have to shut down its normal production processes. In addition, the fault must be located and repaired quickly because if a second fault occurs, the fault acts like a phase-to-phase fault extending the repair process. Advantages * Offers a low value of current flow for line-to-line ground fault (5A or less). * Presents no flash hazard to personnel for accidental line-to-ground fault. * Assures continued operation of processes on the first occurrence of a line-to-ground fault. * Low probability of line-to-ground arcing fault escalating to phase-to-phase or 3-phase fault. Disadvantages * Difficult to locate line-to-ground fault. * Doesn't control transient overvoltages. * Cost of system maintenance is higher due to labor involved in locating ground faults. * A second ground fault on another phase will result in a phase-to-phase short circuit. 2. Solidly grounded. This type of grounding system is most commonly used in industrial and commercial power systems, where grounding conductors are connected to earth ground with no intentional added impedance in the circuit. A main secondary circuit breaker is a vital component required in this system, although it has no bearing in other grounding systems. This component is large in size because it has to carry the full load current of the transformer. Back-up generators are frequently used in this type of grounding system in case a fault shuts down a production process. When this happens, the generators become solidly grounded. However, it's important to note that the generators aren't designed for the larger short circuit current associated with solidly grounded systems. A solidly grounded system has high values of current ranging between 10kA and 20kA. This current flows through grounding wires, building steel, conduit, and water pipes, which can cause major damage to equipment and shut down production processes. When a line-to-ground fault occurs, arcing can create flashes-generally in the terminating box. In this enclosed area, water is turned to steam, causing the terminating box. To locate the fault, all you need to do is follow the smoke. Advantages * Good control of transient overvoltage from neutral to ground. * Allows user to easily locate faults. * Can supply line-neutral loads. Disadvantages * Poses severe arc flash hazards. * Requires the purchase and installation of an expensive main breaker. * Unplanned interruption of production process. * Potential for severe equipment damage during a fault. * High values of fault current. * Likely escalation of single-phase fault to 3-phase fault. * Creates problems on the primary system. 3. High-resistance grounding. High-resistance grounding (HRG) systems are commonly used in plants and mills where continued operation of processes is paramount in the event of a fault. High-resistance grounding is normally accomplished by connecting the high side of a single-phase distribution transformer between the system neutral and ground, and connecting a resistor across the low-voltage secondary to provide the desired lower value of high side ground current. With an HRG system, service is maintained even during a ground fault condition. If a fault does occur, alarm indications and lights help the user quickly locate and correct the problem or allow for an orderly shutdown of the process. An HRG system limits ground fault current to between 1A and 10A. Advantages * Limits the ground fault current to a low level. * Reduces electric shock hazards. * Controls transient overvoltages. * Reduces the mechanical stresses in circuits and equipment. * Maintains continuity of service. * Reduces the line voltage drop caused by the occurrence and clearing of a ground fault. Disadvantages * High frequencies can appear as nuisance alarms. * Ground fault may be left on system for an extended period of time. Grounding of an electrical system is a decision many of us face on a daily basis. As we've seen, several methods exist to accomplish this task, each offering its own advantages and disadvantages. As an electrical designer or installation professional its up to you to make the final decision as to when best to install the most appropriate system. Azad M Patel Electrical Engineer
