Colleagues, I just went through this! Concur mostly with John. The helpful diagrams from Eaton (and others) make it appear that 1077-rated protectors be inside your equipment, and there's a certain logic to that since one can assume the wires and protected component have the extra user-protection of being inside an enclosure. I believe the law (UL standards, NEC) requite 489 breakers on the main panel, and 1077-devices 'downstream' from there. The downstream devices don't have to be in the enclosure with the 1077 protectors. Stay safe! Colorado Brian
From: John Allen <[email protected]> To: [email protected] Subject: Re: [PSES] Circuit Breakers Date: Wed, 30 Oct 2024 01:44:54 +0000Hi Steve, My understanding is Branch Circuit Protection vs Supplementary is not dependent on the device it’s protecting. It’s based on where in the grid you are installed. The way I think about it is branch circuit protection is used to provide wire protection from the transformer outside a building/residence and supplementary protectors are used to provide equipment protection. So, if your motors are internal, Supplementary should be adequate. Lol, what’s the Standard say?? - ---------------------------------------------------------------- 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
