Normally the trefoil (or quadrafoil with neutral - is that a word ? you know what I mean I hope ) groups are kept a bundle diameter or two apart on the tray/ rack or whatever , so there is air flow between and no big extra group of groups  derating factor - have you over done the derating  by mistake ?

(an old discussion thread may help)


How many bundles did you have in parallel, and are you assuming aluminium core or copper core singles. Perhaps start at 3 or  4 bundles at 500- 700a per bundle and see how that looks, then try one size up or one down from there.  The size and number of the transformer terminals can be also be used as a clue to what the makers are expecting.  Each bundle needs all 3 phases and  a neutral nearby, NOT a bundle of phase 1 and another bundle of phase 2 etc.

Come back if it makes no sense or does not seem to fit..

M.

Normally the trefoil (or quadrafoil with neutral - is that a word ? you know what I mean I hope ) groups are kept a bundle diameter or two apart on the tray/ rack or whatever , so there is air flow between and no big extra group of groups  derating factor - have you over done the derating  by mistake ?

(an old discussion thread may help)


How many bundles did you have in parallel, and are you assuming aluminium core or copper core singles. Perhaps start at 3 or  4 bundles at 500- 700a per bundle and see how that looks, then try one size up or one down from there.  The size and number of the transformer terminals can be also be used as a clue to what the makers are expecting.  Each bundle needs all 3 phases and  a neutral nearby, NOT a bundle of phase 1 and another bundle of phase 2 etc.

Come back if it makes no sense or does not seem to fit..

M.