Datasheet

Application Note
Created by Traco Electronic AG Arp. www.tracopower.com Date: May 31
th
, 2013 / Rev.: 1.2
/
Page 52 / 52
20W Single & Dual Output
Safety and Installation Instruction
Fusing Consideration
Caution: This power module is not internally fused. An input line fuse must always be used.
This encapsulated power module can be used in a wide variety of applications, ranging from simple stand-alone operation to an
integrated part of sophisticated power architecture. To maximum flexibility, internal fusing is not included; however, to achieve
maximum safety and system protection, always use an input line fuse. The safety agencies require a slow-blow fuse with
maximum rating of 4A for THN 20-12xx modules and 2A for THN 20-24xx modules and 1A for THN 20-48xx modules. Based
on the information provided in this data sheet on Inrush energy and maximum DC input current; the same type of fuse with
lower rating can be used. Refer to the fuse manufacturer’s data for further information.
MTBF and Reliability
The MTBF of THN 20 SERIES of DC/DC converters has been calculated using
Bellcore TR-NWT-000332 Case I: 50% stress, Operating Temperature at 40°C (Ground fixed and controlled environment). The
resulting figure for MTBF is 1’766’000 hours.
MIL-HDBK 217F NOTICE2 FULL LOAD, Operating Temperature at 25°C. The resulting figure for MTBF is 553’000 hours.