Frequently Asked Questions

The Residual current circuit breaker with over-current protection (RCBO), is actually a kind of circuit breaker with leakage protection function. The RCBO has the protection function of leakage, electric shock, overload and short circuit, which can prevent the occurrence of electric shock accidents and avoid fire accidents caused by electric leakage. , Has obvious effect. RCBOs are installed in our common household distribution boxes to ensure people’s personal safety. RCBO is a low-voltage safety protection electrical appliance, which is an effective protection for direct and indirect contact electricity in the low-voltage power grid. The protection action current is determined by the maximum load current of the line in normal operation. The RCBO reflects the residual current of the system. During normal operation, the system The residual current is almost zero. In the event of leakage and electric shock, the circuit generates residual current. This current is not enough for MCBs and Fuses to operate, while leakage protectors will operate reliably. The common size of RCBO’s width is 18mm, 36mm (the same size as 2P RCCB RCD) or larger (the leakage module is separated from the MCB). RCBO can directly protect the load with a circuit loop, which has both leakage protection, short circuit and overload protection. So, the system used for the terminal switch can be more flexible, and compact.

The residual current circuit breaker (RCCB) with another appellation of Residual current device ( RCD) achieves the following protections: protection for users against electric shocks by direct contacts (<30mA), protection for users against electric shocks by indirect contacts (300 mA), protection of the installations against fire risks (300 mA). Usually, The RCCB/RCD should be associated with MCBs for power distribution system. But the RCBO achieve the above mentioned protections (with different settings) in addition to protection against short circuits and cable overload.

Company Question

Dividing line elimination method If the RCBO trips, you can disconnect the branch circuit of the grid first, and only carry out the power transmission test on the main line. If there is no problem with the main line test, then the branch and terminal lines are tested and eliminated in turn to find the fault point. Intuitive inspection method Carry out a careful inspection of the protector and the protected line equipment, such as the corners, branches, crossovers and other complex and prone fault points of the line to find out the fault points. Numerical comparison method You can also use an instrument to test the line and compare the measured value with the previous value to find the fault point. Trial delivery method Finally, check the fault of the RCBO itself. It is recommended to cut off the main circuit breaker, remove the load side wiring of the tripped RCBO, then turn on the RCBO and test the test button. If the RCBO still does not work, it means that the RCBO itself has a problem and needs to be repaired or replaced. It cannot be put into operation. If there is no problem with the RCBO, you need to find the switchboard and wiring. Check whether the insulation of each electrical circuit and instrument is good, etc., and check one by one until the fault point is found. If it is really unclear, please ask professionals to come to repair it.