UL hosts Follow-Up Service (FUS) Forum

	Issue 20 (Winter, 2006)

UL hosts Follow-Up Service (FUS) Forum

To assist manufacturers in continual compliance

This year, the wire and cable (W&C) industry faces various market challenges such as surging raw material costs and the enforcement of the European RoHS directive. Many W&C manufacturers in Greater China step up cost control measures.

Nearly 400 representatives of the W&C industry gathered at a UL forum in Dongguan early November to discuss issues surrounding compliance-related technical issues and safety standards development.

The keynote speeches on the first day centered on business issues that warrant the undivided attention of W&C manufacturers in the region, including supply chain conformances, counterfeit problems, managing product liability risk, and best practices for maintaining continual compliance with safety and RoHS requirements.

End-product manufacturers, including LG and Midea, shared their expectations of their W&C suppliers.

The second day of the forum featured the problem of aging property of PVC compounds, a major raw materials for W&C products. Forum participants also received first-hand update from UL’s principal engineers on developments of W&C related UL Standards, including:

UL 758 for Appliance Wiring Materials
UL 62 for Flexible Cords and Cables
UL 817 Standard for Cord Sets and Power-Supply Cords
UL 588 Standard for Seasonal and Holiday Decorative Products

Some of the frequently-asked questions discussed at the technical sessions are summarized on the following pages.

Wire & Cable Frequently Asked Questions — Part I

General
Q:	Is there a specific order for the elements required in the surface marking? What are the elements required in the surface marking?
A:	Each wire and cable standard indicates the elements that must be surface printed on the wire. These elements may be different depending on the standard. In general, the order of these elements is not specified. However, there are exceptions. For example, if AWM is surface marked and the Recognized logo is used, the words “Appliance Wiring Material” or “AWM” must immediately follow the logo.
Q:	Will the Reference Standard for Electrical Wires, Cables, and Flexible Cords, UL 1581, be obsolete automatically after the implementation of Wire and Cable Test Methods UL 2556?
A:	There will be a transition period. UL 1581 will be revised to reference the methods in UL 2556 in those cases where the methods are the same. All of the standards that currently reference UL 1581 will need to be revised to reference UL 2556. All of the methods that remain in UL 1581 that are not harmonized test methods, such as the Horizontal Flame test for AWM will be moved to the wire standards that require that test. Once all of these steps are completed, UL 1581 will be withdrawn.
Q:	Why does UL require long-term aging to determine the requirements of a material instead of adding the requirements directly to the applicable Standard?
A:	UL needs to gather data from several manufacturers to determine the appropriate requirements for a specific material. Once UL has enough data and had made the determination that the material has consistent properties, a table can be added to the applicable standard with the short-term requirements.
Q:	If manufacturers want to conduct the VW-1 Flame Test by themselves, do they need a UL engineer to witness the testing?
A:	UL must evaluate the flame chamber to determine compliance with UL’s requirements. Once it has been determined that the flame chamber meets UL’s requirements, the chamber may be used for VW-1 flame test for a new work project under the Data Acceptance Program (DAP). The DAP was previously known as Client Test Data Program (CTDP) or Witnessed Test Data Program (WTDP). All testing for Follow-Up Service (FUS) testing must be conducted at UL.
Q:	When manufacturers submit samples for testing, do those samples have thickness requirements? And does buffed specimen have thickness requirement while preparing die-cut?
A:	Normally, UL will test the thinnest thickness to represent thicker thicknesses when evaluating insulation and/or jacket. Testing a thin material is more severe than testing a thick material when air-oven aging is involved in the test method. UL tests the thinnest material as specified in the standard or on the style page in order to give the broadest range of coverage possible. In some cases, buffed specimens are necessary to perform the tensile and elongation test. These samples should be buffed to remove the irregularities, but should not be thinner than the minimum requirement for the component specified in the standard.
Q:	Will UL use DC-Resistance method to judge the size conductor instead of the method of cross-sectional area? Is it the only method to determine the size of conductor?
A:	In many standards, either the DC-Resistance or a dimensional measurement method may be used to determine conductor size. DC-Resistance is a referee method in determining the size of conductor. If the size of the conductor is not compliant when measured by the cross-sectional area method, the DC-Resistance will be used to determine compliance.
Q:	If my samples fail in the FUS test or in the Market Survey, does our manufacturer need to apply for authorization again? If the manufacturer is under IMP, how many additional inspections will the UL Field Representative conduct?
A:	The manufacturer would need to reapply for authorization if a product or file was withdrawn as a result of FUS or Market Survey failures. Typically, under IMP, the manufacturer is subject to two additional inspections and sample selections per month. However, each case is evaluated individually to determine if there are additional circumstances that would require that the IMP be applied differently.