RE: What's the deal with Wire Nuts?
Don, Hi. In your response to Brian you said... However, written into the body of the IEC 60950-1 and EN 60950-1 (and other national derivative standards) is a wiring method for permanent connection to the mains not acceptable in the US and Canada – the use of a non-detachable power supply cord for permanent connection. Can you please supply to me the reference that prohibits that wiring method in US and Canada? Regards Tim Tim Haynes A1N10 Electromagnetic Engineering Specialist SELEX Sensors and Airborne Systems 300 Capability Green Luton LU1 3PG ( Tel : +44 (0)1582 886239 7 Fax : +44 (0)1582 795863 ) Mob: +44 (0)7703 559 310 * E-mail : tim.hay...@selexgalileo.com P Please consider the environment before printing this email. There are 10 types of people in the world-those who understand binary and those who don't. J. Paxman SELEX Sensors and Airborne Systems Limited Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - 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-p...@ieee.org All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
RE: What's the deal with Wire Nuts?(Non-Detachable Power Supply Cords)
Tim, Sure. In clause 3.2.3, “Permanently connected equipment”, it says: “PERMANENTLY CONNECTED EQUIPMENT shall be provided with either (strikethrough): * a set of terminals as specified in 3.3; or (strikethrough) * a NON-DETACHABLE POWER SUPPLY CORD (strikethrough) PERMANENTLY CONNECTED EQUIPMENT having a set of terminals shall:” This has been there since UL 1950 and CSA C22.2 No. 950 of old times. The source of this omission is in the following US National Electrical Code and Canadian Electrical Code, Part I sections: NEC (2008), Article 400 – FLEXIBLE CORDS AND CABLES “400.7 Uses Permitted.” “(B) Attachment Plugs. Where used as permitted in 400.7(A)(3), (A)(6), and (A)(8), each flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet.” “400.8 Uses Not Permitted. Unless specifically permitted in 400.7, flexible cords shall not be used for the following:” (1) As a substitute for the fixed wiring of a structure (4) Where attached to building surfaces (6) Where installed in raceways, except as otherwise permitted in this Code. CSA C22.1, Canadian Electrical Code, Part I (2006), 4-010, Uses of flexible cords (3) Flexible cords shall not be used (a) as a substitute for the fixed wiring of structures and shall not be (i) permanently secured to any structural member; Best Regards, Don Gies, N.C.E Senior Product Compliance Engineer Alcatel-Lucent Murray Hill, NJ 07974-0636 USA From: Haynes, Tim (SELEX GALILEO, UK) [mailto:tim.hay...@selexgalileo.com] Sent: Thursday, November 20, 2008 4:03 AM To: Don Gies; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Don, Hi. In your response to Brian you said... However, written into the body of the IEC 60950-1 and EN 60950-1 (and other national derivative standards) is a wiring method for permanent connection to the mains not acceptable in the US and Canada – the use of a non-detachable power supply cord for permanent connection. Can you please supply to me the reference that prohibits that wiring method in US and Canada? Regards Tim Tim Haynes A1N10 Electromagnetic Engineering Specialist SELEX Sensors and Airborne Systems 300 Capability Green Luton LU1 3PG * Tel : +44 (0)1582 886239 * Fax : +44 (0)1582 795863 * Mob: +44 (0)7703 559 310 * E-mail : tim.hay...@selexgalileo.com P Please consider the environment before printing this email. There are 10 types of people in the world-those who understand binary and those who don't. J. Paxman SELEX Sensors and Airborne Systems Limited Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - 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-p...@ieee.org All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
RE: What's the deal with Wire Nuts?
Flexible cord is not to be used where a permanent wiring system is required, except under certain exceptions. The concern is that flexible cord is not as robust as wiring in conduit or wiring in walls, and over the long-term exposure that permanent installation implies, a flexible cord could become damaged and hazardous. Canada: CEC part 1 2006 rule 4-010 US: NEC 2008 rule 400.7 Jim Eichner, P.Eng. Compliance Engineering Manager Xantrex Technology Inc. e-mail: jim.eich...@xantrex.com web: www.xantrex.com http://www.xantrex.com/ Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Haynes, Tim (SELEX GALILEO, UK) Sent: Thursday, November 20, 2008 1:03 AM To: Don Gies; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Don, Hi. In your response to Brian you said... However, written into the body of the IEC 60950-1 and EN 60950-1 (and other national derivative standards) is a wiring method for permanent connection to the mains not acceptable in the US and Canada – the use of a non-detachable power supply cord for permanent connection. Can you please supply to me the reference that prohibits that wiring method in US and Canada? Regards Tim Tim Haynes A1N10 Electromagnetic Engineering Specialist SELEX Sensors and Airborne Systems 300 Capability Green Luton LU1 3PG ( Tel : +44 (0)1582 886239 7 Fax : +44 (0)1582 795863 ) Mob: +44 (0)7703 559 310 * E-mail : tim.hay...@selexgalileo.com P Please consider the environment before printing this email. There are 10 types of people in the world-those who understand binary and those who don't. J. Paxman SELEX Sensors and Airborne Systems Limited Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England Wales. Company no. 02426132 This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - 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-p...@ieee.org All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - 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-p...@ieee.org All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
RE: What's the deal with Wire Nuts?
Brian, The use of wire nuts on short wire pigtails in a wiring box for connection to the building wiring is primarily a North American wiring method. You can deduce this by looking at the marks on the box that they came in. They most likely have listing marks for the US, Canada, and/or Mexico, and wire sizes are in “AWG”. If, on the other hand, you saw the CE Mark or wire sizes posted in “mm2”, or some other international certification markings, you would have evidence that the use of those wire nuts is an acceptable wiring method elsewhere. More evidence of this can be seen in national deviations found in Annex NAE of UL 60950-1/CSA C22.2 No. 60950-1 vs.the group deviations of EN 60950-1. UL/CSA 69050-1, Annex NAE 3.2.3 describes leads for field wiring connections to be not smaller than 150 mm (6 inches) in length, making reference to sections of the National Electrical Code and Canadian Electrical Code, Part I. Annex NAE 3.2.9 further describes box volume calculations required by the NEC and Canadian Electrical Code for the number of conductors being connected in a wiring box, normally by wire nuts.On the other hand, EN 60950-1 has no such deviations or notations. However, written into the body of the IEC 60950-1 and EN 60950-1 (and other national derivative standards) is a wiring method for permanent connection to the mains not acceptable in the US and Canada – the use of a non-detachable power supply cord for permanent connection. The most universally accepted means for permanent connection to the mains is to use a field wiring terminal block with a current rating 125 % of the current rating of the product it is installed in, certified for the country of deployment. In conjunction, holes should be supplied nearby for accommodation of a conduit system or cable-securing glands. Best Regards, Don Gies, N.C.E Senior Product Compliance Engineer Alcatel-Lucent Murray Hill, NJ 07974-0636 USA From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Monday, November 17, 2008 3:53 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: What's the deal with Wire Nuts? Scott, Does the 60950 standard give examples of what would satisfy the “two independent fixings” requirement? How would a terminal block satisfy this? I have heard that a wire nut can be used for the electrical connection, but you have to also mechanically hold the wires together which can be done with a cable tie. No where have I found this documented, though. The Other Brian From: scott barrows [mailto:sbarro...@yahoo.com] Sent: Monday, November 17, 2008 2:50 PM To: sbarro...@yahoo.com; Ted Eckert; EMC-PSTC@LISTSERV.IEEE.ORG; Aldous, Scott; Kunde, Brian Subject: RE: What's the deal with Wire Nuts? Hello Other Brian, That is a term I have heard from years gone by. A standard does not specifically prohibit them however if you look at IEC 60950 para 3.1.9 it would be difficult to use wire nut that met the requirements of two independent fixings. Most EU standards have a similar discription as well. Best Regards, Scott --- On Mon, 11/17/08, Kunde, Brian brian_ku...@lecotc.com wrote: From: Kunde, Brian brian_ku...@lecotc.com Subject: RE: What's the deal with Wire Nuts? To: sbarro...@yahoo.com, Ted Eckert ted.eck...@microsoft.com, EMC-PSTC@LISTSERV.IEEE.ORG, Aldous, Scott scott.ald...@aei.com Date: Monday, November 17, 2008, 2:31 PM Where does the term, “Redundant Captive Device” come from? The device which has the wire nuts (twist-on wire connectors) is a water chiller used as a peripheral for a piece of laboratory equipment to be sold internationally. The manufacturer is not used to making laboratory equipment, but industrial cooling devices in the US where it maybe acceptable to use wire nuts. Looking at the IEC/EN 61010-1 standard I cannot see any specific requirement for redundant captive device or redundant connection. I do see a statement in 10.5.3b regarding “insulation which supports the TERMINALS shall be made of material that will not soften” due to dissipated heat from current through the connection. I assume that if the plastic cap of a wire nut gets hot from current passing through the connection and softens then the connection will become loose. Some wire nuts are all plastic and the larger ones have a copper spring inside. In either case, it is the plastic that secures the connection. On a crimp type connection (such as a spade lug or crimp splice), even though they have a plastic case, the electrical connection is made from a metal part which is not likely to soften. It would be nice if there was a clear statement (chapter and verse) documenting if wire nuts can be used in Europe or not or some kind of interpretation letter. The Other Brian From: scott barrows
RE: What's the deal with Wire Nuts?
Hello Brian, Off hand, I am unaware of anything preventing the use of a twist-on wire connector in portable equipment, but that doesn’t mean that the prohibition doesn’t exist. Other list members may know of specific cases where the connectors are prohibited. However, the description of the connector covered in electrical tape indicates that the connector is likely used outside of its UL Listing (if it is even a Listed connector.) First, let me state that “Wire-Nut” is a registered trademark of Ideal Industries. If you are looking for information in standards, the term “twist-on wire connector” will be used. Vibration during use is probably not the main issue. There are many types of fixed equipment, such as an air conditioner or other motor driven appliance, where twist-on connectors are used and they are subject to regular vibration. The connectors may see more vibration in these applications than they might see in some portable appliances. However, your description gives me cause to be concerned. UL does List twist-on connectors under category code ZMVV and they have been around for quite a while. (Ideal’s UL file number is E5238 and that should give you an idea as to the age of the product.) The connectors’ Listing does have some very specific requirements. Specific size connectors are Listed only for use with specific wire sizes and types. The installation instructions must be followed closely. Some of the wire connectors specify that you should not twist the wires first. The twisting of the wire connector will twist the wires to make the proper connection. If you see a connector covered with black tape, there is likely a problem. The tape is typically used when there is a concern that the connector will come loose. This is done based on the installer’s experience. If they have had connectors come loose, it is because they are likely using them incorrectly. The tape does not fix anything. Electrical tape will not likely withstand the test of time and the adhesive will degrade. Cheap electrical tape rarely lasts long at all. There are numerous crimp connectors suitable for connecting wires. There are but splices and crimp connectors designed to perform the same purpose as a twist-on connector. The crimp connectors make a good, permanent splice. The twist-on connector is intended for use where connections are made in the field, particularly where they may need to be undone for servicing. Crimp connections and terminal blocks are better options for factory connections. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Monday, November 17, 2008 6:18 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: What's the deal with Wire Nuts? Greetings Experts. This should be an easy one for those who know the answer. What is the deal with Wire Nuts? Where can be they be used, where can’t they be used? Are there different rules for permanently mounted equipment verse portable equipment? Do you have to also use a mechanical device such are a tie wrap? How about black tape? Our company does not use wire nuts but we always had the impression that safety inspectors do not like to see wire nuts in portable equipment. We are evaluating a product made by another company that uses wire nuts on primary wiring with black tape wrapped around it. Is this technique acceptable internationally on portable equipment? Thanks to all in advance for the education. The Other Brian _ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org
RE: What's the deal with Wire Nuts?
Hi Brian, When I worked for UL, I had heard that the use of wire nuts was not acceptable for the EU (CE Marking), but I don’t recall ever seeing the source of this alleged requirement. I have a vague recollection about them not having any type of international certifications, but I’m not sure about that. There is a book, CE Marking Handbook: A Practical Approach to Global Safety Certification, by David Lohbeck, published in 1998, which covers this, but not in depth. You can preview the book on Google. On page 119, that book indicates that “U.S. wire-nuts are not permitted for wire connections.” I don’t believe the source of this statement is provided, and it well may just be the opinion of the author. Scott Aldous Compliance Engineer Advanced Energy Tel: 970-407-6872 Fax: 970-407-5872 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ted Eckert Sent: Monday, November 17, 2008 9:39 AM To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Hello Brian, Off hand, I am unaware of anything preventing the use of a twist-on wire connector in portable equipment, but that doesn’t mean that the prohibition doesn’t exist. Other list members may know of specific cases where the connectors are prohibited. However, the description of the connector covered in electrical tape indicates that the connector is likely used outside of its UL Listing (if it is even a Listed connector.) First, let me state that “Wire-Nut” is a registered trademark of Ideal Industries. If you are looking for information in standards, the term “twist-on wire connector” will be used. Vibration during use is probably not the main issue. There are many types of fixed equipment, such as an air conditioner or other motor driven appliance, where twist-on connectors are used and they are subject to regular vibration. The connectors may see more vibration in these applications than they might see in some portable appliances. However, your description gives me cause to be concerned. UL does List twist-on connectors under category code ZMVV and they have been around for quite a while. (Ideal’s UL file number is E5238 and that should give you an idea as to the age of the product.) The connectors’ Listing does have some very specific requirements. Specific size connectors are Listed only for use with specific wire sizes and types. The installation instructions must be followed closely. Some of the wire connectors specify that you should not twist the wires first. The twisting of the wire connector will twist the wires to make the proper connection. If you see a connector covered with black tape, there is likely a problem. The tape is typically used when there is a concern that the connector will come loose. This is done based on the installer’s experience. If they have had connectors come loose, it is because they are likely using them incorrectly. The tape does not fix anything. Electrical tape will not likely withstand the test of time and the adhesive will degrade. Cheap electrical tape rarely lasts long at all. There are numerous crimp connectors suitable for connecting wires. There are but splices and crimp connectors designed to perform the same purpose as a twist-on connector. The crimp connectors make a good, permanent splice. The twist-on connector is intended for use where connections are made in the field, particularly where they may need to be undone for servicing. Crimp connections and terminal blocks are better options for factory connections. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Monday, November 17, 2008 6:18 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: What's the deal with Wire Nuts? Greetings Experts. This should be an easy one for those who know the answer. What is the deal with Wire Nuts? Where can be they be used, where can’t they be used? Are there different rules for permanently mounted equipment verse portable equipment? Do you have to also use a mechanical device such are a tie wrap? How about black tape? Our company does not use wire nuts but we always had the impression that safety inspectors do not like to see wire nuts in portable equipment. We are evaluating a product made by another company that uses wire nuts on primary wiring with black tape wrapped around it. Is this technique acceptable internationally on portable equipment? Thanks to all in advance for the education. The Other Brian _ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message
RE: What's the deal with Wire Nuts?
It is not a redundant captive device. Scott --- On Mon, 11/17/08, Aldous, Scott scott.ald...@aei.com wrote: From: Aldous, Scott scott.ald...@aei.com Subject: RE: What's the deal with Wire Nuts? To: Ted Eckert ted.eck...@microsoft.com, Kunde, Brian brian_ku...@lecotc.com, EMC-PSTC@LISTSERV.IEEE.ORG Date: Monday, November 17, 2008, 12:08 PM Hi Brian, When I worked for UL, I had heard that the use of wire nuts was not acceptable for the EU (CE Marking), but I don’t recall ever seeing the source of this alleged requirement. I have a vague recollection about them not having any type of international certifications, but I’m not sure about that. There is a book, CE Marking Handbook: A Practical Approach to Global Safety Certification, by David Lohbeck, published in 1998, which covers this, but not in depth. You can preview the book on Google. On page 119, that book indicates that “U.S. wire-nuts are not permitted for wire connections.” I don’t believe the source of this statement is provided, and it well may just be the opinion of the author. Scott Aldous Compliance Engineer Advanced Energy Tel: 970-407-6872 Fax: 970-407-5872 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ted Eckert Sent: Monday, November 17, 2008 9:39 AM To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Hello Brian, Off hand, I am unaware of anything preventing the use of a twist-on wire connector in portable equipment, but that doesn’t mean that the prohibition doesn’t exist. Other list members may know of specific cases where the connectors are prohibited. However, the description of the connector covered in electrical tape indicates that the connector is likely used outside of its UL Listing (if it is even a Listed connector.) First, let me state that “Wire-Nut” is a registered trademark of Ideal Industries. If you are looking for information in standards, the term “twist-on wire connector” will be used. Vibration during use is probably not the main issue. There are many types of fixed equipment, such as an air conditioner or other motor driven appliance, where twist-on connectors are used and they are subject to regular vibration. The connectors may see more vibration in these applications than they might see in some portable appliances. However, your description gives me cause to be concerned. UL does List twist-on connectors under category code ZMVV and they have been around for quite a while. (Ideal’s UL file number is E5238 and that should give you an idea as to the age of the product.) The connectors’ Listing does have some very specific requirements. Specific size connectors are Listed only for use with specific wire sizes and types. The installation instructions must be followed closely. Some of the wire connectors specify that you should not twist the wires first. The twisting of the wire connector will twist the wires to make the proper connection. If you see a connector covered with black tape, there is likely a problem. The tape is typically used when there is a concern that the connector will come loose. This is done based on the installer’s experience. If they have had connectors come loose, it is because they are likely using them incorrectly. The tape does not fix anything. Electrical tape will not likely withstand the test of time and the adhesive will degrade. Cheap electrical tape rarely lasts long at all. There are numerous crimp connectors suitable for connecting wires. There are but splices and crimp connectors designed to perform the same purpose as a twist-on connector. The crimp connectors make a good, permanent splice. The twist-on connector is intended for use where connections are made in the field, particularly where they may need to be undone for servicing. Crimp connections and terminal blocks are better options for factory connections. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Monday, November 17, 2008 6:18 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: What's the deal with Wire Nuts? Greetings Experts. This should be an easy one for those who know the answer. What is the deal with Wire Nuts? Where can be they be used, where can’t they be used? Are there different rules for permanently
RE: What's the deal with Wire Nuts?
What approvals does this other equipment purport to have? Chris From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Kunde, Brian Sent: 17 November 2008 14:18 To: emc-p...@ieee.org Subject: What's the deal with Wire Nuts? Greetings Experts. This should be an easy one for those who know the answer. What is the deal with Wire Nuts? Where can be they be used, where can’t they be used? Are there different rules for permanently mounted equipment verse portable equipment? Do you have to also use a mechanical device such are a tie wrap? How about black tape? Our company does not use wire nuts but we always had the impression that safety inspectors do not like to see wire nuts in portable equipment. We are evaluating a product made by another company that uses wire nuts on primary wiring with black tape wrapped around it. Is this technique acceptable internationally on portable equipment? Thanks to all in advance for the education. The Other Brian _ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: What's the deal with Wire Nuts?
Brian, In my experience, electrical inspectors do not like to see twist-on wire connectors used in equipment due to the perceived potential for them to vibrate loose, usually because they were incorrectly installed in the first place. Some inspectors will insist that they be over-wrapped with approved electrical tape with enough layers to match the insulation thickness of the connected wires. Some just won't accept them at all. For equipment applications, it is up to the reviewing engineers looking at the product during the certification evaluations to determine if the connector is a) suitable for the application and b) approved for the application. This is why they are frequently found inside equipment, but why they are not generally accepted on field-installed equipment (control panels and the like). I believe that Scott Barrows is correct in his comment that they are not redundant, captive devices and thus not acceptable in the EU. As far as I know, these connectors were originally intended for use in building wiring applications on fixed wiring installations, not for applications subject too vibration and shock in normal use. -- Doug Nix, A.Sc.T. IEEE PSES Toronto Section, Ontario, Canada d...@ieee.org mobile (519) 729-5704 fax (519) 653-1318 Find me LinkedIn at http://www.linkedin.com/in/dougnix On Nov 17, 2008, at 9:17, Kunde, Brian wrote: Greetings Experts. This should be an easy one for those who know the answer. What is the deal with Wire Nuts? Where can be they be used, where can’t they be used? Are there different rules for permanently mounted equipment verse portable equipment? Do you have to also use a mechanical device such are a tie wrap? How about black tape? Our company does not use wire nuts but we always had the impression that safety inspectors do not like to see wire nuts in portable equipment. We are evaluating a product made by another company that uses wire nuts on primary wiring with black tape wrapped around it. Is this technique acceptable internationally on portable equipment? Thanks to all in advance for the education. The Other Brian _ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/li strules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and
Re: What's the deal with Wire Nuts?
In message 7995b996909d2a40b3cb7d0db4cceaa90273d...@aedcexcvs1.aei.com, dated Mon, 17 Nov 2008, Aldous, Scott scott.ald...@aei.com writes: On page 119, that book indicates that ?U.S. wire-nuts are not permitted for wire connections.? I don?t believe the source of this statement is provided, and it well may just be the opinion of the author. I think it may be a ruling requested by European test-houses, with supporting evidence of problems, before the formal 'interpretation sheet' procedure was in place. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Either we are causing global warming, in which case we may be able to stop it, or natural variation is causing it, and we probably can't stop it. You choose! John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
RE: What's the deal with Wire Nuts?
Where does the term, “Redundant Captive Device” come from? The device which has the wire nuts (twist-on wire connectors) is a water chiller used as a peripheral for a piece of laboratory equipment to be sold internationally. The manufacturer is not used to making laboratory equipment, but industrial cooling devices in the US where it maybe acceptable to use wire nuts. Looking at the IEC/EN 61010-1 standard I cannot see any specific requirement for redundant captive device or redundant connection. I do see a statement in 10.5.3b regarding “insulation which supports the TERMINALS shall be made of material that will not soften” due to dissipated heat from current through the connection. I assume that if the plastic cap of a wire nut gets hot from current passing through the connection and softens then the connection will become loose. Some wire nuts are all plastic and the larger ones have a copper spring inside. In either case, it is the plastic that secures the connection. On a crimp type connection (such as a spade lug or crimp splice), even though they have a plastic case, the electrical connection is made from a metal part which is not likely to soften. It would be nice if there was a clear statement (chapter and verse) documenting if wire nuts can be used in Europe or not or some kind of interpretation letter. The Other Brian From: scott barrows [mailto:sbarro...@yahoo.com] Sent: Monday, November 17, 2008 12:26 PM To: Ted Eckert; Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG; Aldous, Scott Subject: RE: What's the deal with Wire Nuts? It is not a redundant captive device. Scott --- On Mon, 11/17/08, Aldous, Scott scott.ald...@aei.com wrote: From: Aldous, Scott scott.ald...@aei.com Subject: RE: What's the deal with Wire Nuts? To: Ted Eckert ted.eck...@microsoft.com, Kunde, Brian brian_ku...@lecotc.com, EMC-PSTC@LISTSERV.IEEE.ORG Date: Monday, November 17, 2008, 12:08 PM Hi Brian, When I worked for UL, I had heard that the use of wire nuts was not acceptable for the EU (CE Marking), but I don’t recall ever seeing the source of this alleged requirement. I have a vague recollection about them not having any type of international certifications, but I’m not sure about that. There is a book, CE Marking Handbook: A Practical Approach to Global Safety Certification, by David Lohbeck, published in 1998, which covers this, but not in depth. You can preview the book on Google. On page 119, that book indicates that “U.S. wire-nuts are not permitted for wire connections.” I don’t believe the source of this statement is provided, and it well may just be the opinion of the author. Scott Aldous Compliance Engineer Advanced Energy Tel: 970-407-6872 Fax: 970-407-5872 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ted Eckert Sent: Monday, November 17, 2008 9:39 AM To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Hello Brian, Off hand, I am unaware of anything preventing the use of a twist-on wire connector in portable equipment, but that doesn’t mean that the prohibition doesn’t exist. Other list members may know of specific cases where the connectors are prohibited. However, the description of the connector covered in electrical tape indicates that the connector is likely used outside of its UL Listing (if it is even a Listed connector.) First, let me state that “Wire-Nut” is a registered trademark of Ideal Industries. If you are looking for information in standards, the term “twist-on wire connector” will be used. Vibration during use is probably not the main issue. There are many types of fixed equipment, such as an air conditioner or other motor driven appliance, where twist-on connectors are used and they are subject to regular vibration. The connectors may see more vibration in these applications than they might see in some portable appliances. However, your description gives me cause to be concerned. UL does List twist-on connectors under category code ZMVV and they have been around for quite a while. (Ideal’s UL file number is E5238 and that should give you an idea as to the age of the product.) The connectors’ Listing does have some very specific requirements. Specific size connectors are Listed only for use with specific wire sizes and types. The installation instructions must be followed closely. Some of the wire connectors specify that you should not twist the wires first. The twisting of the wire connector will twist the wires to make the proper connection. If you see a connector covered with black tape, there is likely a problem. The tape is typically used when there is a concern that the connector will come loose. This is done based on the installer’s experience. If they have had connectors come loose, it is because they are likely
RE: What's the deal with Wire Nuts?
Hello Other Brian, That is a term I have heard from years gone by. A standard does not specifically prohibit them however if you look at IEC 60950 para 3.1.9 it would be difficult to use wire nut that met the requirements of two independent fixings. Most EU standards have a similar discription as well. Best Regards, Scott --- On Mon, 11/17/08, Kunde, Brian brian_ku...@lecotc.com wrote: From: Kunde, Brian brian_ku...@lecotc.com Subject: RE: What's the deal with Wire Nuts? To: sbarro...@yahoo.com, Ted Eckert ted.eck...@microsoft.com, EMC-PSTC@LISTSERV.IEEE.ORG, Aldous, Scott scott.ald...@aei.com Date: Monday, November 17, 2008, 2:31 PM Where does the term, “Redundant Captive Device” come from? The device which has the wire nuts (twist-on wire connectors) is a water chiller used as a peripheral for a piece of laboratory equipment to be sold internationally. The manufacturer is not used to making laboratory equipment, but industrial cooling devices in the US where it maybe acceptable to use wire nuts. Looking at the IEC/EN 61010-1 standard I cannot see any specific requirement for redundant captive device or redundant connection. I do see a statement in 10.5.3b regarding “insulation which supports the TERMINALS shall be made of material that will not soften” due to dissipated heat from current through the connection. I assume that if the plastic cap of a wire nut gets hot from current passing through the connection and softens then the connection will become loose. Some wire nuts are all plastic and the larger ones have a copper spring inside. In either case, it is the plastic that secures the connection. On a crimp type connection (such as a spade lug or crimp splice), even though they have a plastic case, the electrical connection is made from a metal part which is not likely to soften. It would be nice if there was a clear statement (chapter and verse) documenting if wire nuts can be used in Europe or not or some kind of interpretation letter. The Other Brian From: scott barrows [mailto:sbarro...@yahoo.com] Sent: Monday, November 17, 2008 12:26 PM To: Ted Eckert; Kunde, Brian ; EMC-PSTC@LISTSERV.IEEE.ORG; Aldous, Scott Subject: RE: What's the deal with Wire Nuts? It is not a redundant captive device. Scott --- On Mon, 11/17/08, Aldous, Scott scott.ald...@aei.com wrote: From: Aldous, Scott scott.ald...@aei.com Subject: RE: What's the deal with Wire Nuts? To: Ted Eckert ted.eck...@microsoft.com, Kunde, Brian brian_ku...@lecotc.com, EMC-PSTC@LISTSERV.IEEE.ORG Date: Monday, November 17, 2008, 12:08 PM Hi Brian, When I worked for UL, I had heard that the use of wire nuts was not acceptable for the EU (CE Marking), but I don’t recall ever seeing the source of this alleged requirement. I have a vague recollection about them not having any type of international certifications, but I’m not sure about that. There is a book, CE Marking Handbook: A Practical Approach to Global Safety Certification, by David Lohbeck, published in 1998, which covers this, but not in depth. You can preview the book on Google. On page 119, that book indicates that “ U.S. wire-nuts are not permitted for wire connections.” I don’t believe the source of this statement is provided, and it well may just be the opinion of the author. Scott Aldous Compliance Engineer Advanced Energy Tel: 970-407-6872 Fax: 970-407-5872 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ted Eckert Sent: Monday, November 17, 2008 9:39 AM To: Kunde, Brian ; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Hello Brian, Off hand, I am unaware of anything preventing the use of a twist-on wire connector in portable equipment, but that doesn’t mean that the prohibition doesn’t exist. Other list members may know of specific cases where the connectors are prohibited. However, the description of the connector covered in electrical tape indicates that the connector is likely used outside of its UL Listing (if it is even a Listed connector.) First, let me state that “Wire-Nut” is a registered trademark of Ideal Industries. If you are looking for information in standards, the term “twist-on wire connector” will be used. Vibration during use is probably not the main issue. There are many types of fixed equipment, such as an air conditioner or other motor driven appliance, where twist-on connectors are used and they are subject to regular vibration. The connectors may see more vibration in these applications than they might see in some portable appliances. However, your description gives me cause to be concerned. UL does List
RE: What's the deal with Wire Nuts?
Scott, Does the 60950 standard give examples of what would satisfy the “two independent fixings” requirement? How would a terminal block satisfy this? I have heard that a wire nut can be used for the electrical connection, but you have to also mechanically hold the wires together which can be done with a cable tie. No where have I found this documented, though. The Other Brian From: scott barrows [mailto:sbarro...@yahoo.com] Sent: Monday, November 17, 2008 2:50 PM To: sbarro...@yahoo.com; Ted Eckert; EMC-PSTC@LISTSERV.IEEE.ORG; Aldous, Scott; Kunde, Brian Subject: RE: What's the deal with Wire Nuts? Hello Other Brian, That is a term I have heard from years gone by. A standard does not specifically prohibit them however if you look at IEC 60950 para 3.1.9 it would be difficult to use wire nut that met the requirements of two independent fixings. Most EU standards have a similar discription as well. Best Regards, Scott --- On Mon, 11/17/08, Kunde, Brian brian_ku...@lecotc.com wrote: From: Kunde, Brian brian_ku...@lecotc.com Subject: RE: What's the deal with Wire Nuts? To: sbarro...@yahoo.com, Ted Eckert ted.eck...@microsoft.com, EMC-PSTC@LISTSERV.IEEE.ORG, Aldous, Scott scott.ald...@aei.com Date: Monday, November 17, 2008, 2:31 PM Where does the term, “Redundant Captive Device” come from? The device which has the wire nuts (twist-on wire connectors) is a water chiller used as a peripheral for a piece of laboratory equipment to be sold internationally. The manufacturer is not used to making laboratory equipment, but industrial cooling devices in the US where it maybe acceptable to use wire nuts. Looking at the IEC/EN 61010-1 standard I cannot see any specific requirement for redundant captive device or redundant connection. I do see a statement in 10.5.3b regarding “insulation which supports the TERMINALS shall be made of material that will not soften” due to dissipated heat from current through the connection. I assume that if the plastic cap of a wire nut gets hot from current passing through the connection and softens then the connection will become loose. Some wire nuts are all plastic and the larger ones have a copper spring inside. In either case, it is the plastic that secures the connection. On a crimp type connection (such as a spade lug or crimp splice), even though they have a plastic case, the electrical connection is made from a metal part which is not likely to soften. It would be nice if there was a clear statement (chapter and verse) documenting if wire nuts can be used in Europe or not or some kind of interpretation letter. The Other Brian From: scott barrows [mailto:sbarro...@yahoo.com] Sent: Monday, November 17, 2008 12:26 PM To: Ted Eckert; Kunde, Brian ; EMC-PSTC@LISTSERV.IEEE.ORG; Aldous, Scott Subject: RE: What's the deal with Wire Nuts? It is not a redundant captive device. Scott --- On Mon, 11/17/08, Aldous, Scott scott.ald...@aei.com wrote: From: Aldous, Scott scott.ald...@aei.com Subject: RE: What's the deal with Wire Nuts? To: Ted Eckert ted.eck...@microsoft.com, Kunde, Brian brian_ku...@lecotc.com, EMC-PSTC@LISTSERV.IEEE.ORG Date: Monday, November 17, 2008, 12:08 PM Hi Brian, When I worked for UL, I had heard that the use of wire nuts was not acceptable for the EU (CE Marking), but I don’t recall ever seeing the source of this alleged requirement. I have a vague recollection about them not having any type of international certifications, but I’m not sure about that. There is a book, CE Marking Handbook: A Practical Approach to Global Safety Certification, by David Lohbeck, published in 1998, which covers this, but not in depth. You can preview the book on Google. On page 119, that book indicates that “ U.S. wire-nuts are not permitted for wire connections.” I don’t believe the source of this statement is provided, and it well may just be the opinion of the author. Scott Aldous Compliance Engineer Advanced Energy Tel: 970-407-6872 Fax: 970-407-5872 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ted Eckert Sent: Monday, November 17, 2008 9:39 AM To: Kunde, Brian ; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: What's the deal with Wire Nuts? Hello Brian, Off hand, I am unaware of anything preventing the use of a twist-on wire connector in portable equipment, but that doesn’t mean that the prohibition doesn’t exist. Other list members may know of specific cases where the connectors are prohibited. However, the description of the connector covered in electrical tape indicates that the connector is likely used outside of its UL Listing (if it is even a Listed connector.) First, let me state that “Wire-Nut” is a registered trademark of Ideal Industries. If you
