For the purposes of meeting safety creepage and clearance spacings (EN60950, UL1950, CSA 950, etc.), the core (ferrite or powdered iron) is considered to be a conductor.
The core can be considered to be part of the primary circuit or part of the secondary circuit or a "dead metal part" depending on the construction of the transformer, type of wire insulation used, etc. Spacings have to be met accordingly. Paul Ruggier, Tectrol Inc, Toronto, Canada. ____________________Reply Separator____________________ Subject: TNV Transformer Spacings Author: <[email protected]> List-Post: [email protected] Date: 2/25/98 5:48 PM Hello All, I received some transformer samples for a modem front end circuit that are supposed to have been designed to UL1950 and IEC950 creepage dimensions. It appears that the spacings would be correct if the core material was not considered. I believe this to be an oversight made by the transformer designer. Is the ferrite core considered a conductive material? If so, do the primary-secondary distances apply to each winding and the core material? Thanks in advance, Rich Kalian Aware, Inc. [email protected]
