[BC] HT Transformer

[clive@citiria.com]

< am making this inquiry on behalf of a friend in another market. He has a
<BE FM35T with 3 phase closed-delta power service. He has surge protection,
<but I don't know the particulars. The TX was new in March 2000. In March
<2004, the plate transformer shorted (not sure whether primary or secondary).
<No other problems. A few days ago, the replacement plate transformer
<developed shorted turns (output voltage low and heating). There appear to
<be no other problems upstream or downstream of the plate transformer. The
<brand of the transformer appears to be "SNC". I am not familiar with that
<brand.

Assuming this is (very likely) an open-frame type and not oil-immersed, the
failure of the replacement is almost certainly due to the engineer not having
sufficient training and experience.
Open-frame HT transformers MUST be conditioned and properly insulation tested
before being put into service. Usually takes 2 - 4 days. Otherwise you can expect
early failure in exactly the way you described.
Clive Warner.