more Recognized Plastics Directory
PSNet - including Mel Pedersen... Why would you, Mel, look any other place then to UL for a Plastics Recognized Component Directory? From the beginning of their history UL has focused on fire prevention in electrical installations and equipment. This focus has been reinforced because of the North American use of lower voltage for commercial and residential systems than those used in Europe and much of the rest of the world. This lower voltage (V/2) draws a higher current (2xI) which leads to 4x the heating effect (remember I**2 x R) and, historically, more fires in equipment and installations. This UL focus joined with the other forces at work within UL to develop methods for pre-qualification of plastic materials for use in installation components (wiring, switches, outlets etc) and equipment. Thus, the world's largest public database - the UL Plastics Recognized Component Directory. The European approach (until more recently) was not to qualify materials, but qualify parts and pieces of construction using tests such as the Oxygen Index test on finished pieces. This methodology meant that the same material used in another configuration would be tested again and again. So there is plenty of European data, but it doesn't seem to be published in any useable form available to worldwide users. With the ongoing harmonization of standards on a worldwide basis, even the Europeans recognize the benefit of pre-qualification of materials and have been accepting this approach in many standards... IEC 950 and IEC 1010 make heavy use of these prequalified materials to demonstrate adequacy in any application... Moreover, over the last 20 or more years, UL has been quietly moving their requirements into IEC (e.g. IEC 60674 -1, 2, 3-2,3-3, 3-4 to 6, 3-7 (and European standards)) so that the UL database is now more important than ever in showing compliance to the requirements stated in the standards... Further, plastics manufacturers worldwide submit their materials to UL for evaluation enlarging the usefulness of this database. There is some competition, CSA publishes a directory... CAN/CSA-C22.2 No. 0.17-92 (R1997) evaluation of Properties of Polymeric Materials. The Canadian requirements shadow the UL requirements. They have been accepting materials for evaluation for the last 10 years or so. The last CSA directory I used was quite a bit thinner than the UL directory... Well, I didn't intend for this to be a UL sales pitch, but do believe that their large database will be the basis of choice for selection of plastics materials for use in equipment meeting worldwide requirements. - - - - - Peter E Perkins Principal Product Safety Consultant Tigard, ORe 97281-3427 +1/503/452-1201 phone/fax p.perk...@ieee.org email visit our website: http://ourworld.compuserve.com/homepages/peperkins - - - - -
RE: more Recognized Plastics Directory
Forgot to forward this to newsgroup. - Mel -- From: Mel Pedersen[SMTP:mpeder...@midcom.anza.com] Sent: Thursday, March 19, 1998 9:18 AM To: 'Peter E. Perkins' Subject: RE: more Recognized Plastics Directory Hello Peter, Your point is well taken, however, I am not interested in flammability data. I am curious about differences in the Thermal Index ratings given by European agencies versus UL. Thermal Index ratings given by European agencies against the IEC 216-1 standard. IEC 216-1 is the corresponding IEC standard to UL 746B for the purposes of determining thermal indexes. In looking at new materials, I sometimes see manufacturers declarations for service temperature ratings that don't seem to match up with the RTI numbers that UL publishes. I am starting to believe that sometimes these "advertised" ratings are given according to the IEC method. It is interesting that sometimes these manufacturers declare a temperature rating against IEC 85, which is the IEC analog to the UL 1446 insulation system standard. The difference between the IEC and UL methods is that UL uses a control material during these aging test, and the IEC standards (from what I understand, I don't have a copy) do not specify use of a control. I have heard that this results often in a 5 to 10 degree C difference, with UL's number generally being more conservative. Also, when a manufacturer advertises a temperature rating in their catalog, they often don't specify at what thickness that rating is for, or other relevant information. That is why I am looking for a "European" recognized component directory. Thanks Peter. Any other thoughts would be appreciated. Mel PedersenMidcom, Inc. Homologations Engineer Phone: (605) 882-8535 mpeder...@midcom.anza.com Fax: (605) 886-6752 -- From: Peter E. Perkins[SMTP:peperk...@compuserve.com] Sent: Thursday, March 19, 1998 12:44 AM To: PSNetwork Subject:more Recognized Plastics Directory PSNet - including Mel Pedersen... Why would you, Mel, look any other place then to UL for a Plastics Recognized Component Directory? From the beginning of their history UL has focused on fire prevention in electrical installations and equipment. This focus has been reinforced because of the North American use of lower voltage for commercial and residential systems than those used in Europe and much of the rest of the world. This lower voltage (V/2) draws a higher current (2xI) which leads to 4x the heating effect (remember I**2 x R) and, historically, more fires in equipment and installations. This UL focus joined with the other forces at work within UL to develop methods for pre-qualification of plastic materials for use in installation components (wiring, switches, outlets etc) and equipment. Thus, the world's largest public database - the UL Plastics Recognized Component Directory. The European approach (until more recently) was not to qualify materials, but qualify parts and pieces of construction using tests such as the Oxygen Index test on finished pieces. This methodology meant that the same material used in another configuration would be tested again and again. So there is plenty of European data, but it doesn't seem to be published in any useable form available to worldwide users. With the ongoing harmonization of standards on a worldwide basis, even the Europeans recognize the benefit of pre-qualification of materials and have been accepting this approach in many standards... IEC 950 and IEC 1010 make heavy use of these prequalified materials to demonstrate adequacy in any application... Moreover, over the last 20 or more years, UL has been quietly moving their requirements into IEC (e.g. IEC 60674 -1, 2, 3-2,3-3, 3-4 to 6, 3-7 (and European standards)) so that the UL database is now more important than ever in showing compliance to the requirements stated in the standards... Further, plastics manufacturers worldwide submit their materials to UL for evaluation enlarging the usefulness of this database. There is some competition, CSA publishes a directory... CAN/CSA-C22.2 No. 0.17-92 (R1997) evaluation of Properties of Polymeric Materials. The Canadian requirements shadow the UL requirements. They have been accepting materials for evaluation for the last 10 years or so. The last CSA directory I used was quite a bit thinner than the UL directory... Well, I didn't intend for this to be a UL sales pitch, but do believe that their large database will be the basis of choice for selection of plastics materials for use in equipment meeting worldwide requirements. - - - - - Peter E Perkins Principal Product Safety Consultant Tigard, ORe 97281-3427 +1/503/452-1201 phone/fax p.perk...@ieee
Re: more Recognized Plastics Directory
Mel Pedersen wrote: > > Forgot to forward this to newsgroup. - Mel > > -- > From: Mel Pedersen[SMTP:mpeder...@midcom.anza.com] > Sent: Thursday, March 19, 1998 9:18 AM > To: 'Peter E. Perkins' > Subject: RE: more Recognized Plastics Directory > > Hello Peter, > > Your point is well taken, however, I am not interested in flammability data. > I am curious about differences in the Thermal Index ratings given by European > agencies versus UL. > > > > Also, when a manufacturer advertises a temperature rating in their catalog, > they often don't specify at what thickness that rating is for, or other > relevant information. That is why I am looking for a "European" recognized > component directory. > > Thanks Peter. Any other thoughts would be appreciated. > > Mel PedersenMidcom, Inc. > Homologations Engineer Phone: (605) 882-8535 > mpeder...@midcom.anza.com Fax: (605) 886-6752 > > -- > From: Peter E. Perkins[SMTP:peperk...@compuserve.com] > Sent: Thursday, March 19, 1998 12:44 AM > To: PSNetwork > Subject:more Recognized Plastics Directory > > PSNet - including Mel Pedersen... > > Why would you, Mel, look any other place then to UL for a Plastics > Recognized Component Directory? From the beginning of their history UL has > focused on fire prevention in electrical installations and equipment. This > focus has been reinforced because of the North American use of lower > voltage for commercial and residential systems than those used in Europe > and much of the rest of the world. This lower voltage (V/2) draws a higher > current (2xI) which leads to 4x the heating effect (remember I**2 x R) and, > historically, more fires in equipment and installations. This UL focus > joined with the other forces at work within UL to develop methods for > pre-qualification of plastic materials for use in installation components > (wiring, switches, outlets etc) and equipment. Thus, the world's largest > public database - the UL Plastics Recognized Component Directory. > > The European approach (until more recently) was not to qualify > materials, but qualify parts and pieces of construction using tests such as > the Oxygen Index test on finished pieces. This methodology meant that the > same material used in another configuration would be tested again and > again. So there is plenty of European data, but it doesn't seem to be > published in any useable form available to worldwide users. > > With the ongoing harmonization of standards on a worldwide basis, > even the Europeans recognize the benefit of pre-qualification of materials > and have been accepting this approach in many standards... IEC 950 and IEC > 1010 make heavy use of these prequalified materials to demonstrate adequacy > in any application... Moreover, over the last 20 or more years, UL has > been quietly moving their requirements into IEC (e.g. IEC 60674 -1, 2, > 3-2,3-3, 3-4 to 6, 3-7 (and European standards)) so that the UL database is > now more important than ever in showing compliance to the requirements > stated in the standards... Further, plastics manufacturers worldwide > submit their materials to UL for evaluation enlarging the usefulness of > this database. > > There is some competition, CSA publishes a directory... > CAN/CSA-C22.2 No. 0.17-92 (R1997) evaluation of Properties of Polymeric > Materials. The Canadian requirements shadow the UL requirements. They > have been accepting materials for evaluation for the last 10 years or so. > The last CSA directory I used was quite a bit thinner than the UL > directory... > > Well, I didn't intend for this to be a UL sales pitch, but do > believe that their large database will be the basis of choice for selection > of plastics materials for use in equipment meeting worldwide requirements. > > - - - - - > > Peter E Perkins > Principal Product Safety Consultant > Tigard, ORe 97281-3427 > > +1/503/452-1201 phone/fax > > p.perk...@ieee.org email > > visit our website: > > http://ourworld.compuserve.com/homepages/peperkins > > - - - - - Mel, You are on the right track... UL's RTIs are determined by many factors, including thickness, where the material will be used, how the material will be used, and how the material matches up to similar material used in a similar fashion (the control). These are just the basic factors. This is how the same material can get many different RTIs at different thicknesses, or even the same thickness. A m
