Jim, The category description is what tells the user/installer what factors were considered as part of the Listing or need to be considered as part of the product's use or installation. It would seem to me that this is important. For example, the category "guide" information for NWGQ includes not only that UL1950 is the standard that is used but also that the equipment is intended for installation in accordance with the NEC. It also has info regarding installation in "computer rooms", use and testing of equipment that might be installed in environmental air space, etc.
The category guide for primary protectors (i.e. carbon blocks, etc.) includes information concerning codes that are used to identify the fusing bridal wire that must be used at the installation to afford adequate protection. The "custom-built" category guide includes codes and information that can be used by installers or inspection authorities to help make sure the equipment is compatible and installed correctly. The "Communication Service Equipment" category guide includes a reference to the NESC as well as the NEC, since this equipment might be used in areas not covered by the NEC, such as up on shared facility utility poles, pedestal sites, etc..It also talks about the minimum outdoor environmental conditions that are considered (temperature range, rain, etc.), protection issues (since some devices incorporate primary protection) and the like. CSA has a similar system in place that describes the certification category as does UL's c-UL program for Canada. I'm not sure about the other labs. UL has a Canadian category for Communication Service Equipment (DUZO7). We have a number of Listings in this category and I have not heard anything about it not being accepted. (We have also issued (at the mfrs request) some IEC950 CB reports on equipment that was covered under this category and included the additional requirements we considered important as an addendum to the basic report!) There is nothing unusual about another specification (such as a Bellcore GR) referencing a standard rather than a category. In fact, this would be the right way to do it. If the entire standard is referenced then by right the equipment must meet the entire referenced specification to comply with the clause in the basic spec. Sometimes, like for the AC Power Fault Tests in GR-1089-CORE , 4.5.13 note 10, only a portion of the spec is relevant to the AC power fault tests (the UL1459 overvoltage tests) and I would say that this type of reference would not require or imply complete compliance with everything else since the note is specific to this section. The GR is only looking for the data and an indication of compliance with the overvoltage test. (This is also a good example of what I talked about earlier where a spec is referenced but modified....GR-1089 requires one of the UL1459 tests to be modified up to 277 Volts.) R4-5 of 1089 states "shall be listed for the purpose". For most customer premises equipment, WYQQ or NWGQ would be appropriate since the equipment is on the protected side of the NI and the resulting "listing" would show compliance with UL1459 or UL1950. However, an SIU that provides the network interface, isolation and primary protection would be "listed for the purpose" if it were covered under DUZO since this category covers the relevant safety issues while a listing under WYQQ or NWGQ would probably not be appropriate "for the purpose" of its actual usage. Randy Ivans Business Sector Coordinator Telecommunications Industry email: [email protected]
