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Frequently Asked Questions

General Wire & Cable FAQs

1 - What is the relationship between the UL Standards for Wire and Cable and the National Electrical Code?

The large majority of UL's wire and cable Standards are intended to be compatible with the installation requirements of the National Electrical Code (NEC). Some exceptions are Boat Cable, Marine Shipboard Cable, and Appliance Wiring Material. UL staff devotes significant resources to the development of the NEC, which is published by the National Fire Protection Association (NFPA).

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2 - Does an E-number on a product mean that it is UL Listed?

No. The UL "E-number" is a valid identifier for the organization responsible for a product but not an indication that the product is Listed, Classified, Verified or Recognized. Only the appropriate UL Mark- on the wire or cable or on its packaging - is a valid indication of UL certification. UL assigns a unique "E-number" (E + 3 to 6 digit number for wire and cable products) to each applicant in every product category. To find the responsible organization for a product when the "E-number " has been used for identification, go to UL's Online Certifications Directory and select Search By UL File Number and enter the appropriate E-number.

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3 - Why are ampacity markings not permitted on UL Listed wire and cable, and not shown in UL wire and cable Standards?

The ampacity of a wire or cable is the amount of current that the wire or cable can transmit without exceeding its rated temperature. An ampacity marking on a wire or cable or a reference to a specific ampacity for a wire or cable in a UL wire or cable standard is not feasible since ampacity varies according to the actual conditions under which the cable will operate. These conditions include the ambient temperature, installation environment e.g. free-air, conduit or directly buried in the earth. The National Electrical Code provides two methods for the cable user to determine ampacity for a cable based on the installation conditions.

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4 - What does the term "Verified" mean?

The term "Verified" when used in a UL marking means that the product has been tested and complies with a specific requirement(s). These requirements may be safety or performance related. In the UL system the words "Classified" and "Verified" mean the same thing. For a complete explanation of "Listed", "Classified" and "Recognized" read up on the UL Mark.

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5 - What is the best source of information on the intended use of a UL Listed wire or cable product?

The guide information for most of UL’s product categories provides valuable information regarding intended use and installation requirements. To view this information, go to UL's Online Certifications Directory. Use the Keyword Search to determine the links to files that are appropriate. Each file contains an additional link to the guide information.

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6 - Do the style numbers for Appliance Wiring Material have any significance (ie: 1015)?

The significance of the numbering systems is as follows:

For additional information, refer to the guide information for category AVLV2 – Appliance Wiring Material.

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7 - The Appliance Wiring Material Style Pages include text such as, "Marking - See page 13." What document does this reference?

The UL Appliance Wiring Material Style Pages are currently being revised. References within the style pages are obsolete. Instead, refer to the guide information for AVLV2 – Appliance Wiring Material.

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FAQs for UL 758, the Standard for Appliance Wiring Materials

1. Are Style Pages being retained?

Style Pages continue to be used as the main method of describing individual AWM constructions. It has been rumored that they would be deleted.

In the development phase of UL 758, it was proposed that Style Pages be eliminated, in favor of a "Ratings and Use Code" system. For example, Style 1015 would become "I B 105C 600V H". Such "Ratings and Use Codes" corresponded to voltage and temperature ratings, mechanical abuse ratings, flame ratings, etc. However, in discussing this issue with various groups, such as UL Staff, manufacturers, end-product industry groups, etc., it was determined that Style Pages provide unique identifiers for individual AWM constructions. This is very similar to the way people can easily recognize and visualize a SJTW Flexible Cord, or a 4-Pair 24 AWG Type CMR Performance-Verified Category 5 cable. Therefore, UL elected to keep Style Pages, along with making them available on UL's website.

You can also view Style Pages and Current Listings Online.

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2. If Style Pages are being maintained, what is changing?

Each Style Page will now reference "UL 758" as the "Standard" used for determining the requirements for each Style. This would include such requirements as standardized Tensile Strength and Elongation requirements, Spark Testing requirements, Dielectric voltage withstand requirements, etc.

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3. Why was UL 758 developed?

UL 758 was developed to consolidate requirements. Over the 40 years the category has been in existence, many people have had different interpretations of how to evaluate the wire. These procedures evolved over time. In addition to the 124 page Section General, many "desktop" standards or outlines were used to evaluate wire constructions. So that all customers and users of AWM were aware of the test protocol and requirements, and that consistency was maintained, UL 758 was formed.

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4. How different is the format of the Standard versus the "AWM Section General"?

The two documents are very different.

As manufacturers and UL Staff requested clarification on various issues over the years, policy statements and test methods were added to the Section General. Sometimes they were added in chronological order, in order to reduce the renumbering of the pages. Although a Table of Contents was available in the AWM Section General, referencing specific requirements was time consuming, as similar topics were located on different pages in the Section General.

UL 758 follows the standardized format for UL's Standards for Safety:

1. Foreword: Includes UL corporate policy statements regarding the Standard and its use.
2. Introduction: Includes the Scope of the Standard, an explanation on the units of measurement used.
3. Construction: Contains the most generic requirements for individual components of the product. For AWM, this would include conductor requirements, insulation and jacket, and other general requirements.
4. Performance: Contains all test requirements determined necessary for a particular product to qualify under UL's AWM requirements.
5. Manufacturing and Production Tests: These are the tests that are required of the manufacturer, typically on 100% of all production.
6. Marking: How the product is to be marked in order to be considered as Recognized AWM. The marking section includes surface print marking, and marking of the engineering tags that accompany the finished AWM. UL labeling (Recognition Mark) requirements are specified in the Follow-Up and Inspection Instructions (FUII), which is contained in each Manufacturer's Follow-Up Service Procedure.

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Below are the individual paragraphs and page number of UL 758, as of February 9, 2004:

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5. How will the format for the Follow-Up Service Procedures be affected by the use of UL 758, instead of using the AWM Section General?

There is little effect on the format of the AWM Follow-Up Service Procedures. There are more changes to the overall documentation system for AWM. You can review the summary of each component of the AWM documentation system, with changes marked in bold.

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6. What are the major technical changes to each AWM Style?

There are few technical changes. Instead, most of the requirements are consolidated in UL 758. Here are the most significant changes with affect marking or testing requirements:

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7. How do you determine which tests are required on a particular style number?

The Subject 758 bulletin dated February 15, 2001 describes how to use the information on a style page to determine what tests are required from UL 758. It also describes how to determine what tests are required on a proposed new style.

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8. What if I find an error in UL 758?

Due to large variety of Styles currently covered by UL 758, there may be situations where a requirement is not specifically applicable. UL 758 has undergone several revisions since the original publication based on comments from users of the standard. Please report any errors you find to the Conformity Assessment Service contacts noted below.

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9. Is UL 758 going to be harmonized with CSA 22.2 no. 210?

There are currently no harmonization efforts underway. It has been determined that it would be prudent to wait until UL 1581 is harmonized with its' Canadian equivalent CSA 22.2, No 0.3 since so many of the requirements in UL 758 reference UL 1581.

If you have a compelling reason to accelerate the harmonization of UL 758, please contact Susan Stene at Susan.L.Stene@us.ul.com or phone +1-408-876-2948.

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10. Can any style be rated VW-1?

Yes, any style can be rated and marked VW-1 as long as it meets the requirements in the standard. Wires and Cables marked VW-1 are subject to monthly sampling by your local Field Representative.

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11. What if I have specific questions regarding AWM, and I need to contact someone at UL?

UL's testing offices have trained wire and cable personnel that can answer your questions. Shown below is list of these UL contacts and two separate lists have been provided depending upon the nature of the inquiry. Conformity Assessment Services personnel can answer questions regarding testing needs and requirements, such as qualifying a Manufacturer to manufacture a particular Style ("New Work Investigations"), and test methods. Typically, Follow-Up Service Inspection issue contacts can answer questions regarding labeling and marking issues, and FUS inspection policies and procedures. In some instances, the personnel are the same.

For Manufacturers, it is best that they contact the personnel show below at their "Reviewing Office", where they normally submit their products for the New Work Investigations.

Reviewing Office Contacts for New Work Investigations for Appliance Wiring Material:

Reviewing Office Contacts for Follow-Up Service Issues for Appliance Wiring Material:

Please note that personnel may change without notice. However, UL will attempt to keep the personnel listing on this Web site updated as best possible.

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12. How are the braidless silicone requirements in Tables 7.1 and 7.2 of UL 758 applied to current styles?

If a style page specifies Class 22, or if the style page has a use statement which says "... where not subject to movement or mechanical abuse" or the like, or if the construction has a braid, class 22 requirements, found in Table 50.210 of UL 1581, apply. If the style does not have any of the constraints listed above, the requirements in Tables 7.1 and 7.2 apply.

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We hope that this provides you all the information that you need on the changes regarding UL 758. If you have any questions regarding AWM, or the content of this website page, please contact the above personnel at the nearest UL office, or your "Reviewing Office" for your AWM Follow-Up Service Procedure.

Thanks!

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