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Three Phase RCD & MCB Wiring?

Nano Brewery
Please could somebody advise on the most cost effective procedure of wiring up RCDs & MCBs on a DIN Rail for independent circuit protection.  Tried Googling to no joy.  Plenty of Single Phase advice, images, videos.  If using 4 Pole MCBs & RCDs, would I be correct in assuming that similar to single phase, it's just a case of Busbar-ing the MCB Lives to the RCD Lives and taking the RCD to Neutral Bar?


Have seen diagrams (like below) where the Incoming L1, L2, L3 get split to separate DP MCBs, RCDs and SP MCBs for each phase.  Seems like a bit of a faff and a pricey option (3x DP MCBs + 3x RCDs + 3x SP MCBs) per circuit.


I have 3x Three Phase Circuits (13A, 40A, 48A) that I wish to protect independently with RCDs.


Thanks in advance!  Dan.

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    For your reference a real 3 phase board of the kind with the 123 123 123 busbar pattern looks like this. Note that an 12 way 3 phase board has 36 outgoing wires, in 12 groups of 3wires  (or 4 if you include the neutral - and you have to include the neutral for an RCD.)

    something like your 3 phase pump will expect 4 wires, 3 of which are ganged together.

    Look at the pictureshalfway down this page to see what 3 phase MCBs look like.

    Mike.

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  • 0
    For your reference a real 3 phase board of the kind with the 123 123 123 busbar pattern looks like this. Note that an 12 way 3 phase board has 36 outgoing wires, in 12 groups of 3wires  (or 4 if you include the neutral - and you have to include the neutral for an RCD.)

    something like your 3 phase pump will expect 4 wires, 3 of which are ganged together.

    Look at the pictureshalfway down this page to see what 3 phase MCBs look like.

    Mike.

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