Assume UL 508A Marking is:
-----Original Message----- From: MIKE SHERMAN <[email protected]> Sent: May 15, 2024 10:38 PM To: <[email protected]> Subject: Re: [PSES] SCCR Rating Question Brian — I am equally mystified by qualifying an SCCR with a voltage. Perhaps you could network into a friendly UL 408a panel shop and see what they say. Mike Sherman Sherman PSC LLC On 05/15/2024 9:05 AM -05 Brian Kunde <[email protected]> wrote: I appreciate the replies, but I am not getting the information I am seeking. Some machines have just the SCCR Rating, such as SCCR: 10kA but a few machines we have looked at include a reference to the "Max Voltage", such as SCCR: 10kA RMS Symmetrical, 480V Maximum What is the source, code, standard, directive, etc. that calls out the Max Voltage as a requirement in the SCCR rating that is printed on the Nameplate label? We cannot find such a source. In our case, we have a machine that can operate at 230V, 380V, or 480V depending on how the motor is wired. So on a machine rated 230V it has a SCCR rating that includes the Max Voltage of 480V. We are getting push-back from the field saying that having the voltage on the SCCR rating is confusing. To resolve this, we want to remove the reference to the Max Voltage, but before we do that, we want to find out if it is mandated in the code or some standard. I can see where the max voltage might be required on some components. Maybe it is an old requirement that is no longer required. I am just guessing. Thanks again for your help. The Other Brian On Tue, May 14, 2024 at 3:54 PM Scott Aldous <[email protected] (mailto:[email protected])> wrote: Starting on page 7, the white paper that Rich linked to also references UL 508A, supplement SB, which is a method of determining SCCR for industrial control panels without test. The method at a high level involves carrying over the SCCR rating of the "weakest link in the chain" from a protective component standpoint to the overall panel. I wonder if that method may have been used for the machinery in question, with a component level voltage rating (improperly, in my opinion) shifted over to the end device. Note that UL 508A includes "at a nominal voltage" in its definition of SCCR. On Tue, May 14, 2024 at 12:33 PM Richard Nute <[email protected] (mailto:[email protected])> wrote: Hi Brian: See the very last line of: https://www.mouser.com/pdfDocs/littelfuse_industrial_whitepaper_increase_sccr.pdf Best regards, Rich From: Ralph McDiarmid <[email protected] (mailto:[email protected])> Sent: Tuesday, May 14, 2024 11:41 AM To: [email protected] (mailto:[email protected]) Subject: Re: [PSES] SCCR Rating Question Could this number to used to select a suitable circuit breaker and so the interrupting voltage is an important parameter? The nameplate rating on the machine should be the information an electrician needs during installation and selection of wire size and type. Ralph From: Brian Kunde <[email protected] (mailto:[email protected])> Sent: Tuesday, May 14, 2024 11:29 AM To: [email protected] (mailto:[email protected]) Subject: [PSES] SCCR Rating Question Greetings to all. I am new to SCCR ratings on industrial machinery. The ratings I have seen sometimes has a "Maximum Voltage" included, such as; SCCR: 22kA, 600V Maximum Where does the voltage value come from? In one case, the machine had a line voltage rating of "120/208 Vac", but the SCCR rating had a voltage rating of "Max 600V". Can this be confusing? Might something think the machine can operate at 600Vac? Thanks for any replies. 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] (mailto:[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] (mailto:[email protected]) Rick Linford at: [email protected] (mailto:[email protected]) For policy questions, send mail to: Jim Bacher at: [email protected] (mailto:[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 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] (mailto:[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] (mailto:[email protected]) Rick Linford at: [email protected] (mailto:[email protected]) For policy questions, send mail to: Jim Bacher at: [email protected] (mailto:[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 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] (mailto:[email protected]) All emc-pstc postings are archived and searchable on the web at: Website: https://ewh.ieee.org/soc/pses/ (https://www.mail-archive.com/[email protected]/) 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] (mailto:[email protected]) Rick Linford at: [email protected] (mailto:[email protected]) For policy questions, send mail to: Jim Bacher at: [email protected] (mailto:[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 -- Scott Aldous | Regulatory Compliance Manager | [email protected] (mailto:[email protected]) | 650-253-1994 (tel:(650)%20253-1994) 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] (mailto:[email protected]) All emc-pstc postings are archived and searchable on the web at: Website: https://ewh.ieee.org/soc/pses/ (https://www.mail-archive.com/[email protected]/) 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] (mailto:[email protected]) Rick Linford at: [email protected] (mailto:[email protected]) For policy questions, send mail to: Jim Bacher at: [email protected] (mailto:[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 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/ (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] (mailto:[email protected]) Rick Linford at: [email protected] (mailto:[email protected]) For policy questions, send mail to: Jim Bacher at: [email protected] (mailto:[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 This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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