| UL 62 |
| Q: |
Why UL has the requirement on lay of conductors as
Table 10, UL 62 required? Will UL consider a larger lay of conductors or remove this requirement? Will UL use testing to determine the compliance of lay of conductors as other testing organization does instead of controlling it? |
| A: |
 Lay of conductors is necessary for the flexibility of the cord. If the length of lay is longer and the cable is subject to flexing, there may be stress points, which may cause a breakage of conductor or cracking of the insulation. If UL were to choose to use a performance requirement rather than a prescriptive requirement for the length-of-lay of insulated conductors, we would have to very clearly define the specific construction that was subject to testing. Material manufacturer and grade designations, fillers and other constructional items would be specifically defined and the manufacturer would not be granted the ability to modify the construction. In addition, UL would need to determine the appropriate test or tests to be used to as certain that the cable construction could withstand the abuses may experience during actual use. UL is currently in discussion with industry to determine if we can set performance requirements. |
| Q: |
Can the requirements of conductor material be changed in UL 62? Can copper-clad aluminum (CCA) or other material be used as conductor? When making a stranded conductor, can individual wire be stranded with nylon fiber? |
| A: |
According to CL. 4.1.1.2 of UL 62, conductors shall be of annealed copper in compliance with ASTM B 3 or NMX-J-036-ANCE, or annealed coated copper in compliance with ASTM B 33 or NMX-J-008-ANCE. In order to change this requirement UL would require documentation showing that the CCA conductors can withstand the same mechanical and environmental abuses as the copper described above. Issues such as flexibility, corrosion and connectability would need to be addressed. UL is currently in discussion with members of industry on this matter.
In order to add a nylon fiber or other strength member to the conductor, a special evaluation and procedure description is required.
|
| Q: |
Do UL Recognized wires have to bear labels in other countries except for in mainland China? |
| A: |
All Recognized and Listed wires, regardless of country of origin must bear the Listing Mark label. |
| Q: |
Why did UL replace the long-term insulation resistance test with the Permitivity and Stability Factor Test for “W” rated cables? If samples selected at the manufacturer during routine FUS sampling do not pass these tests before the effective date of 2008-05-31, will “W” rated cords be withdrawn? |
| A: |
 Due to the harmonization of UL 62, CSA C22.2 No. 49 and Mexico Standard, UL no longer requires long-term insulation resistance test for wet-rated PVC insulation materials. If complying results are not obtained by the
effective date, all PVC insulated cords with “W” rating will be withdrawn. |
| Q: |
The UL Field Representative still requires our
manufacturer to use QMTT2 compounds for Type SJTW. Is this the correct requirement now? If not, will UL notify the IC? |
| A: |
Until May 31, 2008, or until your compound has been evaluated for Permitivity and Stability Factor, the QMTT2 material is still required in “W” rating cables. Once it has been determined that your compound can comply with the Permitivity and Stability Factor tests, the requirement for a QMTT2 compound will be deleted from your Follow-Up Service Procedure file. |
| Q: |
Will UL sample every type with “W” rating
for testing the Permitivity and Stability Factor Test? Will every temperature rating be sampled? |
| A: |
UL will select representative samples to cover the range of “W” cords manufactured. UL will not select every type or every temperature rating. |
| Q: |
Will UL 62 be revised to include specific tests from end product standards? |
| A: |
The tests in UL 62 cover the general evaluations that most end product standards
require. However, each end product standard may have unique requirements that are not covered in UL 62. These evaluations take place at the time the end product is evaluated. If all of these unique tests were incorporated into UL 62, the test program for each cord would
increase greatly. |
