Which one best ELCB and RCCB?

Both ELCB and RCCB are designed to protect against electric shock and electrocution, and both are effective at doing so. The choice between the two depends on the specific needs and requirements of the application.

RCCB is considered to be more advanced and reliable than ELCB, as it monitors the current flowing in the live and neutral wires, as well as the current flowing to earth. This means that RCCB is able to detect and respond to a wider range of electrical faults, including those that may not be picked up by an ELCB.

Additionally, RCCB are more sensitive and can detect leakage current as low as 10mA and trip the breaker while ELCB need to detect 30mA before tripping.

However, ELCB is simpler, less expensive, and requires less wiring than RCCB. Therefore, if cost is a major concern, ELCB may be a more suitable choice.

In summary, RCCB is considered to be more advanced and reliable, while ELCB is simpler and less expensive. It ultimately depends on the specific needs of the application and budget.