Question

Q2. A three phase circuit breaker is rated 2000 MVA, 33 kV. What will be its making current?

Answer 1

Answer:

89

p=√3vi

so 2000mva=√3×33kv×I

I=35kA

now

I making= 2.55× braking current

so the making current is

=2.55×35

=89

Answer 2

Answer:

If a three phase circuit breaker is rated 2000 MVA, 33 kV, then its making current is 89 KA.

Explanation:

Because the dc offset during fault conditions is taken into consideration, the manufacturing capacity is expressed as a peak value. The greatest current in rms that the circuit breaker can interrupt is referred to as the circuit breaker's breaking capability.

$\(I_{\text {Making }}=2.55^{*} I_{\text {Braking }}\)$

$\(I_{\text {Braking }}=P / V=2000\) MVA \(/(\sqrt{3} * 33 \mathrm{KV})=89000\) Ampere \(=89 \mathrm{KA} .\)$