1- Three Phase RCCB- Residual Current Circuit Breaker:

Three phase RCCB is used in domestic and industries. It is safety device which protect to human and very sensitive equipments like as data center, computers etc.

RCCB is main working function is leakage current sensing. It is an electromechanical protective device which is used for prevention of leakage current, earth leakage. It is also provides protection against electrical shock.

2- Three Phase RCCB Connection Diagram.

3- Three Phase RCCB Working Principle:

Basic principle:

The basic function of RCCB is the same of Kirchhoff current law.

• If incoming current vector sum and outgoing current vector sum is same then in this condition, RCCB will not be tripped.
• If incoming current vector sum and outgoing vector sum is not same then it shows that current is leakage condition and RCC will be tripped.

It works on current basis. It detects leakage current. Phase outgoing current and neutral incoming current should be equal during without fault. When any phase touches with body then phase current will not be receive on neutral end point resultant phase flowing current and receiving current on neutral will not be equal. In that situation the RCCB will monitor preset value of leakage current like as 30 mA,100mA,300mA if the leakage current is more than preset value then it will interrupted the live circuit. In this way the equipment will be safe.

4- Why Three Phase RCCB is Used:

Three phase RCCB is mostly used where the minimum leakage current is not acceptable or very sensitive equipment just like as servers, data centers and IT sectors. It is also important of human safety.

In domestic and industries many equipment and lighting circuits are used. Equipment live wire may be connect with metal body then the current will be pass on body. If any human touches equipment then he will get shock. So this condition is very dangers to the human. Other reason is due to leakage current, system may be heat or fire case in system.
So RCCB is used for equipment and human safety.

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