Jeff, The normal practice is to wind a thermal protective device in the transformer. For larger transformers it is normally a resetable device but for small transformers, a one time operation type is often used.
On Fri, 4 Dec 1998, JENKINS, JEFF wrote: > Hi folks, > > I have a question about transformer fusing. I have an application that uses > a 10W transformer connected across 400Vac mains. It is my understanding > that this requires a fuse rated to at least 400V, which would mean 500V > because that's the next larger size available. However, the smallest > amperage fuse available at that voltage rating is 100mA. This by far > exceeds the transformer rating. I thought about performing the EN 60742 > test of loading the transformer until the primary current is 2.1 x 100 mA = > 210 mA and taking thermal measurements, but I am quite sure the transformer > will burn up under this large a load. > > The standards being used to evaluate this product are: > EN 50178 > UL 1012 > CSA C22.2 No. 107.1 > > Any suggestions? > > Regards, > > Jeff Jenkins > Senior Regulatory Compliance Engineer > Advanced Energy Industries, Inc. > Fort Collins, CO USA 80525 > > Opinions are my own and not necessarily shared by Advanced Energy > Industries, Inc. or its affiliates. > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > Chris Healy Liaison Manager, Standards and Approvals JNA Telecommunications Limited email: ch...@jna.com.au A Lucent Technologies Company Ph (direct) : +61 2 9935 5728 16 Smith St, Chatswood, NSW 2067 AUSTRALIA Fax : +61 2 9417 3862 --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
