Brian, The fault tests must be conducted with branch circuit fuses or breakers anticipated at the supply during installation. So, for a 30 A unit connected to a 30 A central office noninal -48/60 V supply, you should be conducting test with 1.5 x 30 A - 45 A or next larger fuse available in the country of destimation.
For a 12-16 A mains operated unit in the US, the branch circuit fuse you would be conducting fault testing is 20 A. For same unit rated up to 12 A, the branch circuit fuse is 15 A. For power suipply tests, I advise my clientele to test at the highest branch circuit fuse they believe their power supplies might be installed. It is of no use to the end-product manufacturer of CO equipment rated 30 A to chose a power supply that has been tested by fault tests at 15A or 20 A. There are many things that are not written in the standards because of the various local codes in the various countries. The UL60950 standard for example, refers you to the National Electrical Code (NEC) and this is where you find information regarding branch circuit fuses at the installation. -----Original Message----- From: Brian O'Connell To: [email protected] Sent: 2/22/02 9:28 PM Subject: 60950 SFC Good People of PSTC My notes from an agency (60950) seminar state that fault conditions shall be done with 16A installation fuses. I cannot find any clause in EN60950:2000 or UL60950, 3d Ed with this requirement. Is this test requirement in one the stds listed in 60950, or am I blind? R/S, Brian O'Connell Taiyo Yuden (USA), Inc. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
