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Circuit protection for distribution circuit

Can 3 individual mcbs(instead of a 3 or 4 pole mcb) be used for circuit protection of a 3 phase distribution circuit, where a 4 or 5 core swa is used? Is there a requirement that all phases must be disconnected in the event of a fault?

  • It would effectively be 3 single phase circuits sharing a neutral. Which brings to mind neutral currents. If for example, three single phase 40A circuits sharing a neutral of a 10mm SWA would result in 120A neutral currents.. too much

    But how is it ok for meter tails to be the same size on 3 phase supplies?

  • Yes if they were all on the same phase; no if they are different phases.

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