I am working on an Industrial Machine with a 3-phase 5hp motor driven by a VFD. To pass the EMC conducted emissions requirements, we had to add a RF Line Filter that is recommended by the VFD manufacturer. This filter has large Y-Caps. I know these currents theoretically cancel out in a balanced system, but when performing the traditional Touch Current test according to IEC 60990 6.2.2.2, Fault Condition No. 1 (open Protective Conductor) we measure a current about 50mA.
However, the standard says that "this subclause do not apply to reliably earthed equipment. . . .". This Industrial Machine is either permanently wired or it can use an industrial grade plug and socket, so this fault test would not apply. So even though the measured current is high if we perform this fault test, because the machine is well grounded I do not have to do anything? In contrast, the IEC 62368 would require a warning label, warning in the manual, and a secondary PE terminal. I have read comments online such as, "in the industrial environment, they don't give a hoot about leakage current." Is this true? On the other hand, an industrial machine could be the size of a building and have dozens of VFD driven motors and line filters creating a huge amounts of currents in an unbalance environment. So in my case, do I have any concerns other than to insure the machine is well bonded to PE during installation? But isn't this a normal installation consideration? Thanks to all. The Other Brian - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to [email protected] All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/[email protected]/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected] Rick Linford at: [email protected] For policy questions, send mail to: Jim Bacher: <[email protected]> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
