Re: [PSES] SCCR Rating Question
We have an answer from UL508A for industrial panels but the question was, “ SCCR ratings on industrial machinery” Perhaps it is the question that is the difficulty here. Ralph From: Bill Lawrence Sent: Thursday, May 16, 2024 2:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] SCCR Rating Question Assume UL 508A Marking is: -Original Message- From: MIKE SHERMAN mailto:msherma...@comcast.net> > Sent: May 15, 2024 10:38 PM To: mailto:EMC-PSTC@LISTSERV.IEEE.ORG> > 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 mailto:bkundew...@gmail.com> > 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 <0220f70c299a-dmarc-requ...@listserv.ieee.org <mailto:0220f70c299a-dmarc-requ...@listserv.ieee.org> > 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 mailto:ri...@ieee.org> > 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 mailto:rmm.priv...@gmail.com> > Sent: Tuesday, May 14, 2024 11:41 AM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 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 mailto:bkundew...@gmail.com> > Sent: Tuesday, May 14, 2024 11:29 AM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 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 EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> 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) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html
Re: [PSES] SCCR Rating Question
Assume UL 508A Marking is: -Original Message- From: MIKE SHERMAN Sent: May 15, 2024 10:38 PM To: 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 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 <0220f70c299a-dmarc-requ...@listserv.ieee.org (mailto:0220f70c299a-dmarc-requ...@listserv.ieee.org)> 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 mailto:ri...@ieee.org)> 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 mailto:rmm.priv...@gmail.com)> Sent: Tuesday, May 14, 2024 11:41 AM To: EMC-PSTC@LISTSERV.IEEE.ORG (mailto:EMC-PSTC@LISTSERV.IEEE.ORG) 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 mailto:bkundew...@gmail.com)> Sent: Tuesday, May 14, 2024 11:29 AM To: EMC-PSTC@LISTSERV.IEEE.ORG (mailto:EMC-PSTC@LISTSERV.IEEE.ORG) 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 EMC-PSTC@LISTSERV.IEEE.ORG (mailto:EMC-PSTC@LISTSERV.IEEE.ORG) All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ 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: msherma...@comcast.net (mailto:msherma...@comcast.net) Rick Linford at: linf...@ieee.org (mailto:linf...@ieee.org) For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org (mailto:j.bac...@ieee.org) To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTCA=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 EMC-PSTC@LISTSERV.IEEE.ORG (mailto:EMC-PSTC@LISTSERV.IEEE.ORG) All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pst
Re: [PSES] SCCR Rating Question
I suggest that John has “nailed it”, as he often does. Ralph From: John Woodgate Sent: Wednesday, May 15, 2024 7:26 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] SCCR Rating Question I cant help you with a reference to a standard, but there is a language problem and I think I can help with that, in the context of 'confusion'. The 'SSCR voltage' on the nameplate actually means 'Minimum permitted value of the Maximum voltage of the SSCR'. Obviously those words are too long to put on the nameplate. In your case, obviously, the Max voltage of the SSCR must be at least 480 V if the motor is wired for 480 V operation, but could be lower if it's wired for a lower voltage. To document this, you would need a BIG nameplate. Some standards allow a sign, usually a '!', to mean 'Refer to manual' or words to that effect, where you can put a full explanation. On 2024-05-15 15:05, Brian Kunde 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 <0220f70c299a-dmarc-requ...@listserv.ieee.org <mailto:0220f70c299a-dmarc-requ...@listserv.ieee.org> > 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 mailto:ri...@ieee.org> > 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 mailto:rmm.priv...@gmail.com> > Sent: Tuesday, May 14, 2024 11:41 AM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 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 mailto:bkundew...@gmail.com> > Sent: Tuesday, May 14, 2024 11:29 AM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 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 EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> 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) <https://e
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 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 <0220f70c299a-dmarc-requ...@listserv.ieee.org> 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 <ri...@ieee.org> 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 <rmm.priv...@gmail.com> Sent: Tuesday, May 14, 2024 11:41 AMTo: EMC-PSTC@LISTSERV.IEEE.ORGSubject: 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 <bkundew...@gmail.com> Sent: Tuesday, May 14, 2024 11:29 AMTo: EMC-PSTC@LISTSERV.IEEE.ORGSubject: [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 li
Re: [PSES] SCCR Rating Question
I cant help you with a reference to a standard, but there is a language
problem and I think I can help with that, in the context of 'confusion'.
The 'SSCR voltage' on the nameplate actually means 'Minimum permitted
value of the Maximum voltage of the SSCR'. Obviously those words are too
long to put on the nameplate. In your case, obviously, the Max voltage
of the SSCR must be at least 480 V if the motor is wired for 480 V
operation, but could be lower if it's wired for a lower voltage. To
document this, you would need a BIG nameplate. Some standards allow a
sign, usually a '!', to mean 'Refer to manual' or words to that effect,
where you can put a full explanation.
On 2024-05-15 15:05, Brian Kunde 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
<0220f70c299a-dmarc-requ...@listserv.ieee.org> 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 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
*Sent:* Tuesday, May 14, 2024 11:41 AM
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*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
*Sent:* Tuesday, May 14, 2024 11:29 AM
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*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
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Re: [PSES] SCCR Rating Question
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 < 0220f70c299a-dmarc-requ...@listserv.ieee.org> 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 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 >> *Sent:* Tuesday, May 14, 2024 11:41 AM >> *To:* EMC-PSTC@LISTSERV.IEEE.ORG >> *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 >> *Sent:* Tuesday, May 14, 2024 11:29 AM >> *To:* EMC-PSTC@LISTSERV.IEEE.ORG >> *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 >> EMC-PSTC@LISTSERV.IEEE.ORG >> >> All emc-pstc postings are archived and searchable on the web at: >> https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ >> <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> >> >> Website: https://ewh.ieee.org/soc/pses/ >> Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to >> unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> >> List rules: https://ewh.ieee.org/soc/pses/listrules.html >> >> For help, send mail to the list administrators: >> Mike Sherman at: msherma...@comcast.net >> Rick Linford at: linf...@ieee.org >> >> For policy questions, send mail to: >> Jim Bacher at: j.bac...@ieee.org >> -- >> >> To unsubscribe from the EMC-PSTC list,
Re: [PSES] SCCR Rating Question
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 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 > *Sent:* Tuesday, May 14, 2024 11:41 AM > *To:* EMC-PSTC@LISTSERV.IEEE.ORG > *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 > *Sent:* Tuesday, May 14, 2024 11:29 AM > *To:* EMC-PSTC@LISTSERV.IEEE.ORG > *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 > EMC-PSTC@LISTSERV.IEEE.ORG > > All emc-pstc postings are archived and searchable on the web at: > https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ > <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> > > Website: https://ewh.ieee.org/soc/pses/ > Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to > unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> > List rules: https://ewh.ieee.org/soc/pses/listrules.html > > For help, send mail to the list administrators: > Mike Sherman at: msherma...@comcast.net > Rick Linford at: linf...@ieee.org > > For policy questions, send mail to: > Jim Bacher at: j.bac...@ieee.org > -- > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=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 > EMC-PSTC@LISTSERV.IEEE.ORG > > All emc-pstc postings are archived and searchable on the web at: > https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ > <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> > > Website: https://ewh.ieee.org/soc/pses/ > Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to > unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> > List rules: https://ewh.ieee.org/soc/pses/listrules.html > > For help, send mail to the list administrators: > Mike Sherman at: msherma...@comcast.net > Rick Linford at: linf...@ieee.org > > For policy questions, send mail to: > Jim Bacher at: j.bac...@ieee.org > -- > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=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 > EMC-PSTC@LISTSERV.IEEE.ORG > All emc-pstc postings are archived and searchable on the web at: > https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ > > Website: https://ewh.ieee.org/soc/pses/ > Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to > unsubscribe) <https://ewh.ieee.org/soc/pses/list.html> > List ru
Re: [PSES] SCCR Rating Question
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 Sent: Tuesday, May 14, 2024 11:41 AM To: EMC-PSTC@LISTSERV.IEEE.ORG 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 mailto:bkundew...@gmail.com> > Sent: Tuesday, May 14, 2024 11:29 AM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 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 EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> 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) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net <mailto:msherma...@comcast.net> Rick Linford at: linf...@ieee.org <mailto:linf...@ieee.org> For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org <mailto:j.bac...@ieee.org> _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC <https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1> =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 EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> 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) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net <mailto:msherma...@comcast.net> Rick Linford at: linf...@ieee.org <mailto:linf...@ieee.org> For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org <mailto:j.bac...@ieee.org> _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC <https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1> =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 EMC-PSTC@LISTSERV.IEEE.ORG All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ 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: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1
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 Sent: Tuesday, May 14, 2024 11:29 AM To: EMC-PSTC@LISTSERV.IEEE.ORG 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 EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> 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) <https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net <mailto:msherma...@comcast.net> Rick Linford at: linf...@ieee.org <mailto:linf...@ieee.org> For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org <mailto:j.bac...@ieee.org> _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC <https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1> =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 EMC-PSTC@LISTSERV.IEEE.ORG All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ 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: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1
[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 EMC-PSTC@LISTSERV.IEEE.ORG All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ 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: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1
