kA rating of an MCB or an MCCB is the maximum current it can safely interrupt in case of a short circuit. If the current goes beyond this value, the circuit breaker could be damaged. kA rating is known as the short circuit withstand capacity or ultimate breaking capacity of a circuit breaker.
What determines the kA rating on a circuit breaker?
kA rating is known as the short circuit withstand capacity or ultimate breaking capacity of a circuit breaker. It is denoted by Icu. For example, if the MCB is rated at 10kA, it means that the MCB can safely break the circuits during short circuit unless until the short-circuited current does not exceed 10kA.
What does 10kA on breaker mean?
The 10 kA you see on a circuit breaker is the interrupting rating of the circuit breaker, that is, the largest current that it can safely open. It is usually written as 10 kA rms symmetrical. The rms indicates that it is rated to interrupt 10 kA root mean square current.
What is the meaning of kA in electrical system?
A kiloampere (kA), is a decimal multiple of the ampere, the SI unit of electric current. To: ampere. kiloampere.
What does kA mean on a fuse?
Kiloamperes. Would be used to rate the interrupting capacity, or the maximum amount of short circuit current the breaker or fuse can disrupt without the case rupturing or exploding.
How do I choose a breaker kA rating?
The maximum amount of current that can flow through a circuit is determined by the size of the transformer feeding the circuit and the length of the cable run from the transformer. This is often called the downstream short circuit current. This will determine the maximum kA rating required for the main circuit breaker.
What does the kA rating on a circuit breaker mean?