0
Pre 1970 (72?) breakers were specified with a MVA assymmetrical interrupting rating. Breakers are now spec'd with a symmetrical rating, which is provided in amps or kA.
There is an ANSI standard that provides conversion from assymetrical to symmetrical and vice versa. Converting from Asym. to symmetrical involves analyzing the open close interval, time between successive openings, breaker operating speed, breaker operating voltage, and whether the breaker is connected to a generator bus or not (usually has an unusually high X/R ratio which results in more DC offset).
So...it is the interrupting rating, or how much (short circuit) power the breaker can interrupt. The faster the breaker operates, the higher the voltage, the closer it is to a generator, and the more times it is expected to open results in a lower interrupting amperage capability. If it is used beyond this rating, it is likely to internally fault when attempting to open.
What else can I help you with?
A transmission line has 30 megawatts and 40 megavars what is the megavolt amps load on the line?
By definition, MVA is equivalent to the vector sum of MW and MVAR: MVA^2 = MW^2 + MVAR^2 = 2500 MVA = 50
What is the capacity of power transformer for 132kva substation?
A 132 kV substation is normally called a grid substation. It would normally use two or more 132/33 kV transformers rated at 90 MVA, or two or more 132/11 kV transformers rated at 30 MVA.
How do you convert MVA into MW?
You would have to know the Power Factor, normally designated PF. MVA x PF = MW. If the PF is unity then MVA = MW. A PF of UNITY suggest the load is purely resistive with neither capacitive nor inductive components in the load or source. Of course this can mean such components have been balanced artificially.
How much power in a 15000 kva transformer?
The power in a 15 MVA (15000 KVA) transformer depends on the power factor. You did not specify the power factor, so I will assume a power factor of 0.92. Simply multiply MVA by PF and you get 13.8 MW.
How do you calculation of selecting Neutral Earthing Transformer?
iT IS ISMILAR TO THE GROUND RESITOR CALCULATION FOR TRANSFOMER THE TYPICAL EXAMPLE WAS ANSWERED EARLIER FOR TRANSFORMER DT.19-06-2009 Neutral of transformer can be grounded solidly earthed OR with Neutral Grounded with Resistance. Typical shunt calculations fro 5 MAV 11/6.6 kv transformer neutral are as :_ Transformer rating = 5 MVA Voltage ratio = 11/6.6 KV Vector Group = Dyn11 (6.6 KV ground through Resistor) During Earth fault voltage between Neutral & Earth = 6.6/√3 = 3.81 KV Earth Fault current will be limited to = 5 x 10³ /(√3 x 6.6) = 437.38Amp. N.G.R. value in ohm = V / I = (3.81 x 10³) / 437.38 = 8.71 Ohm Value of N.G.R. is 437.38 Amp, 8.71 Ohm., 10 Sec NGR are inserted On Higher voltage to restrict earth fault current BY SRI
Transformer rating is expressed in?
VA or KVA or MVA
A transmission line has 30 mw and 40 mvar flowing what is the mva flow on the circuit?
MVA= square root of (MW2 + MVAR2 )
What is breaking capacity in mcb?
I haven't heard of this in relation to a breaker. Breakers will have ratings for short circuit interrupting, max voltage, line charging, etc. A load break switch will have a "breaking capacity", meaning it can be opened as long as the load current is below the breaking rating.
What is the difference between the rupturing capacity and the short circuit breaking capacity?
Rupturing capacity:Rupturing capacity or breaking capacity expresses the current that a circuit breaker is capable of breaking at a given recovery voltage under certain set conditions of operation. It is expressed in MVA The set conditions are power factor,recovery voltage and rate of rise of restriking voltage. When the current broken is symmetrical it is called symmetrical breaking capacity. When the current broken is asymmetrical it is called asymmetrical breaking capacity. It is common to designate circuit breaker capacity based on asymmetrical breaking capacity. Breaking capacity of a circuit breaker =√3xVxIx10-6MVA Short circuit breaking capacity: It is the highest value of short circuit current which a circuit breaker is capable of breaking under specified conditions of transient recovery voltage and power frequency voltage. It is expressed in kA. The breaking current is expressed in two ways1)The r.m.s value of a.c component of current at the instant of contact separtation.2)The percentage of d.c component of current at the instant of contact separtation. While selecting the circuit breaker for a particular location in the power system the fault level at that point is determined.
What is MVA at Plaza?
MVA we are so tight MVA not supposed to fight MVA we are so cool MVA we act like fools. MVA stands for Martina Victoria and Anaya. Bianca not included
How do I convert short circuit current to fault level. I have a 110kV grid which has a maximum short ccircuit current of 30kA?
It is very simple. Use the following equation: Smax=sqrt(3)*V(line-line)*Isc(max) for your case: Smax=5715.76 MVA
How many mega volt ampere are there in a 1 mega watt generator?
In a 1 megawatt (MW) generator, the unit of power is given in terms of megawatts, which represents one million watts. A megavolt-ampere (MVA) is a unit of apparent power equal to one million volt-amperes. Therefore, in a 1 MW generator, the apparent power rating would also be 1 MVA, as the apparent power rating is typically equal to the real power rating in a generator with a power factor of 1.
How do you calculate MVA rating of power transformer?
The product of the secondary rated current and the secondary rated voltage will give you the rated V.A of the transformer.
What does mva mean in electrical terms?
MVA is the apparent power. MVA=( MW+ MVAr)1/2
What kind of power is MVA?
MVA is the aparant power.
What do you mean by fault MVA?
This describes what is known as the 'fault level' at a particular point in an electricity transmission or distribution system, expressed in megavolt amperes, enabling the theoretical value of fault current to be calculated at that point in the system, in order to ensure that the relevant switchgear is capable of interrupting that level of fault current.
What is the population of MVA in Asia?
MVA in Asia's population is 500.
