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Parallel TX Tails - Neutral Arrangement

MW (aka Inrush - for those who remember me!)
So this is the new look forum... Impressive!


I have a question regarding AWA transformer tails. I'm looking at a situation where I need three parallel cables per phase.


My question is related to the neutral conductor arrangement. The neutrals need to be installed between the inter-group trefoils in order to maintain equal current sharing. Therefore, I can either have two neutral conductors of slightly larger CSA to give approx. the same CSA as the overall parallel phase conductors. Or, alternatively, three neutrals of the same CSA as the phase conductors split (oddly) between the two groups.


What convention is normally adopted in this situation?


Many thanks in advance.
  • Former Community Member
    0 Former Community Member

    inrush:

    Thanks, planning to solid bond the armour.



    To some extent, that might depend on the length of the unloading tails, and the disposition you finally go with


    I would always advocate solid bonding and accept the circulating currents as a derating factor as a starting point, however, it may be more equitable to use single point bonding and address the standing voltage issues with your gland selection in some cases.


    Regards


    OMS
  • 0
    "Thanks, planning to solid bond the armour."

    I recall being advised that you can use the unarmoured cable rating if you single point bond the armour. This can make quite a difference but have it confirmed first!

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