What (if any) advantages are there for positioning overload protection at the end of a cable

Good day all

What (if any) advantages are there for positioning overload protection at the end of a cable ?

(presuming fault protection is provided at the beginning)

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  • Does positioning affect Ib <= In <= Iz for any part of the cable ...

  • Does positioning affect Ib <= In <= Iz for any part of the cable ...

    as long as there are no branches before the OPD (i.e. so the OPD sees all the current flowing through the cable it's protecting) then you should be OK.

       - Andy.

  • so one can take the max. current capacity of the cable for the conditions  (so long as fault protection is met at the origin) upto the point of the overload protection...

    in my earlier travels as newbie, there was an example that caught me out ... it was a 50A mcb protecting a run of 2.5T&E to a 1 gang  skt bs1363   ...

    (similar to the spur example mentioned earlier)

    all are effectively relying on overload protection at the 'far end' so to speak  (unless fuses count as fixed load scenarios )

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  • so one can take the max. current capacity of the cable for the conditions  (so long as fault protection is met at the origin) upto the point of the overload protection...

    in my earlier travels as newbie, there was an example that caught me out ... it was a 50A mcb protecting a run of 2.5T&E to a 1 gang  skt bs1363   ...

    (similar to the spur example mentioned earlier)

    all are effectively relying on overload protection at the 'far end' so to speak  (unless fuses count as fixed load scenarios )

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