Zero sequence current protection zero sequence CT installation process to comply with the relevant standards

For the zero-sequence current protection zero sequence CT installation process must comply with the relevant standards. For IT earthing system, as a result of single-phase ground fault, earth fault  Circuit breaker  not only along the cable back into the surface of the conductor, but also could not fault along the cable back into the conductor surface, it must be installed by the cable head ground zero sequence CT, so as to ensure the faulted phase and non-fault phase current through the ground capacitance, which can prevent external fault protection device malfunction, but also to ensure  electric meter  of equipment failure. For IT earthing system, generally installed on the neutral line N zero sequence CT, on the low  mcb circuit breaker  side of the zero-sequence CT busbar must be installed in the neutral line N and the work of ground (or repeating ground) between the busbars . Such as zero-sequence CT installed in the N line distribution panel busbars, power distribution panel metal housing because generally associated directly with the ground electrode, when the bus is shorted to ground occurs, the resulting fault current Id metal casing along the distribution panel → → transformer neutral grounding line flow, rather than through the zero sequence CT, not up to the demands of the protection function, which is in the on-site construction can easily neglect.