Industrial cable markings are a convenient code applied to the jacket or provided on a reeled cable. They are often used for the manufacturer identification, cable type, conductor size, voltage rating, temperature rating, certification references, flame or environmental codes, and production or traceability data. The ability to interpret these markings correctly is the first step in getting an inspection, machine wiring or OEM approval, but these markings are never the final approval document. It is always good to compare the jacket legend with the current datasheet, reel label, purchase specification, and certification record to verify the actual jacket construction and intended use.
A UL, 600V or 90°C mark cannot be assumed to indicate that the cable is acceptable for all applications. Depending on the type of cable, the standard, market and manufacturer, formats, abbreviations and required information can differ. One of the most frequent and expensive errors in industrial procurement and installation is to use an all strings code as the universal code.
What Information Can Be Found on an Industrial Cable?
There are several logical collections of information in most industrial cable legends. Not all items are included in all cables, and the spacing, order, and wording may vary between cable manufacturer and cable family. An example of a print for a jacket is the following (which is just an example print and not a standard print format):
Manufacturer name or trademark • 18 AWG 3C • 600V 90°C • AWM Style XXXX • VW-1 • OIL RES • LOT 24K732
The follow groups provide a description of what these elements might mean.
Manufacturer Name, Brand, and Identification Code
The manufacturer name, trademark or identification number indicates the manufacturer of the cable. This is important if a cable has already been installed in a machine, if it has not been packaged in the same manner as it was when it was manufactured, or if it is being reviewed for a supplier audit. Check with the marking and reel label and buy documents. Packaging with a distributor or reseller name will not be a guarantee of the original manufacturer.
Cable Type, Construction, and Product Designation
The designation might apply to the intended use such as AWM, MTW, control cable, servo cable, robot cable, industrial Ethernet or fieldbus cable. This designation is helpful for the initial screening of first-line sorting but not a full technical specification. The voltage, temperature, bend radius, shielding, conductor class, and environmental performance are still to be confirmed as per datasheet.
Conductor Size, Core Count, and Conductor Material
These can frequently be identified by their AWG or mm² size or by material notes like copper or tinned copper and by the number of conductors or pairs. These values are directly proportional to the present capacity, voltage drop, flexibility and termination practice. Neither 4 × 1.5 mm² nor 18 AWG 3C gives any indication of the cable’s temperature rating, flame performance, shielding, or flex life. Those details are not to be found in the legend or the supporting details.
How to Read Cable Voltage and Temperature Markings
Some of the most common values that are checked during initial screening are voltage and temperature ratings. They are to be read in conjunction with the type of cable and the appropriate standard to which the cable belongs.
Voltage Rating: What 300V, 600V, and Other Values Mean
The voltage marking specifies the rated voltage of the construction of the cable under certain conditions. A 300V or 600V marking does not indicate a cable is “better” or “worse”, or mean it is suitable for all installation methods and end equipment requirements. All of these, the insulation system, the environment where installed and the rating of the equipment must correspond.
Temperature Rating: 60°C, 75°C, 90°C, 105°C, and Beyond
A temperature rating is a marking that usually represents the conductor and/or insulation operating temperature of the product at the highest limit of operating conditions. UL highlights that wires and cables can have dry and wet ratings, in addition to different type designations depending on the type. The number does not necessarily indicate that the entire cable can be exposed to that temperature in all environmental conditions, to all loading conditions, or in a dense control cabinet.
Minimum and Maximum Temperature Information
There is also a minimum operating, installation or flexing temperature for some industrial cables. This is particularly true for cold storage, outdoor machines, auto warehouses and continuous-flex machines. Flexible cables may be rated as having a different continuous operating temperature rating even if the cable is flexible at –40°C during installation.
Why Voltage and Temperature Must Be Read Together
A cable may be rated correctly but not be suitable due to heat close to a cable servo drive, oil exposure, continuous moving or a low bend radius. It is a common situation for engineers to find that a single marking is not enough when inspecting cables for compact control cabinets or machine tools. Acceptance is determined by a complete datasheet and application conditions.
How to Read UL, CSA, IEC, and Other Certification Markings
Certification markings refer to a particular evaluation, recognition or conformance with a particular system. They can’t be switched.
UL Listed, UL Recognized, and UL Style Numbers
UL Listed products are tested for specific end-use categories. For larger products that are Listed, UL Recognized Components, such as most Appliance Wiring Material (AWM), are tested for acceptability under specified conditions. The UL Style number applies to a particular construction that has specific voltage, temperature, insulation, conductor, flame and environmental requirements. A Style number is a required component of the ‘UL AWM’ designation.
What the UL Mark Does and Does Not Prove
The words “UL” or the UL mark on the cable surface are just a secondary name. According to UL guidance, the entire Listing Mark (usually on the reel, coil, flange, or box) is the most important proof of Listing. The surface print will not constitute UL Listing. Check total mark, product identification, manufacturers data and certification history.
CSA, cUL, and CSA Flame Markings
The marking for CSA certifications or test performance are Canadian related. The designations FT1 or FT4 are not full cable approvals. Specify if the marking is to be used for the completed cable, a single conductor or a specific installation situation.
IEC, CE, RoHS, REACH, and Other Claims
An IEC reference can refer to a technical standard. CE marking is related to the European conformity requirements. Both RoHS and REACH cover chemical and material requirements. Having one marking does not automatically fulfill the others. Check the scope of declaration of conformity, product documentation and customer specification.
How to Read UL Style, Flame, and Environmental Codes
Many of the performance or application codes may be used in combination to form a marking. Divide into identification, certification, flame and environmental groups.
UL Style Numbers and AWM Markings
AWM is not a particular construction type but rather a general term for construction under UL 758. There can be multiple different voltage, temperature, material, flame and intended-use requirements for different Style numbers. Always refer to the jacket’s print and manufacturer’s datasheet and the relevant UL record.
Flame Ratings Such as VW-1, FT1, FT4, and IEC 60332
These designations are related to certain test methods. They do not necessarily indicate circuit integrity, low-smoke or halogen-free properties. Identify the marking and match with the datasheet and installation.
Oil, Sunlight, Wet, Tray, and Environmental Designations
If the product is to be used in direct contact with oil, sunlight or wet locations, or for use in trays, or for direct burial, then these characteristics must be associated with the type of product and the use. A cable that has been rated for oil resistance might also need specific testing to verify continuous-flex, temperature, or chemical exposure.
Traceability Codes, Length Markings, and Production Information
Traceability markings facilitate receipt of inspection records, installation records, quality investigation and controlled replacement. Formats are manufacturer-specific.
Date Codes, Lot Numbers, and Batch Identification
Date or lot information links an installed cable to a production record, material batch, or shipment. Request the manufacturer’s code interpretation when formal traceability is required for the project.
Sequential Length Markings
Some cables have sequential meter/footing marks. These assist installers to calculate the remaining length and minimise waste. These are not certificate markings.
Why Traceability Matters for OEMs and Maintenance Teams
If a machine is having intermittent cable failure, the maintenance team should find out which batch and production record. Traceability is particularly useful if the custom cables require application-specific constructions or certification.
A Step-by-Step Method for Reading an Industrial Cable Legend
When inspecting a cable use this sequence. This is a handy inspection process and not an all-encompassing standard.
Step 1 — Identify the Manufacturer and Product Type
Begin with the manufacturer name, trademark, product family or cable type. This information will indicate which datasheet and certification record to open.
Step 2 — Confirm Conductor Size and Cable Construction
Check AWG or mm², core or pair count, conductor material, and visible shielding or construction code. Cables that look alike may vary in these details.
Step 3 — Confirm Voltage and Temperature
Check the rated voltage and temperature and compare them to the equipment specification and installation situations.
Step 4 — Confirm Certification, Flame, and Environmental Requirements
Find UL, AWM, CSA, IEC, flame, oil, wet, sunlight or tray marks associated with the application. Check with documentation.
Step 5 — Confirm Traceability and Documentation
Document the manufacturer, product code, lot/batch number and date marking, reel details and documents prior to installation. This makes maintenance, replacement and audits easier in the future.
Common Mistakes When Reading Industrial Cable Markings
Assuming Every Marking String Follows the Same Format
Order and abbreviations are different from manufacturer to manufacturer, product to product, country to country and standard to standard. Beware of relying on a past experience with a different supplier’s cable to understand an abbreviation. Use the manufacturer’s legend guide/datasheet.
Treating “UL” as Proof of UL Listing
The “UL” symbols are not enough. Verify the Listing Mark or the relevant recognition information on the packaging/reel and verify the certificate record.
Confusing Temperature Rating with Ambient Temperature
The marked temperature is generally the temperature of the conductor or the insulation system, under specified conditions. Consider existing load, bundling, wet or dry sites, heat sources and installation techniques.
Assuming a Flame Code Means the Cable Is Fire Resistant
VW-1, FT1, FT4 or IEC 60332 refer to the performance during a specified flame test. Do not establish circuits for integrity and continued operation during fire.
Ignoring the Reel Label and Datasheet
The jacket print is just one data source. Label on reel, purchase specification, datasheet and product must be consistent. Regular inspection reveals instances in which it is seen as a good print but the reel is a different product or revision.
Replacing a Custom Cable with a Similar-Looking Product
A seemingly similar replacement may be UL Style, conductor class, voltage, temperature, shielding, oil resistance, flex performance etc. different. Please check with engineering before substitutions.
What Engineers and Buyers Should Verify Before Approving a Cable
Marking and Product Identity
- Manufacturer or trademark
- Family/Type of Product
- Conductor size and amount of cores or pairs
- The voltage and temperature ratings.
- UL Style, CSA, IEC or other designation to be applied.
- Fire and other signs of nature.
- Batch, lot or traceability data
Each jacket does not contain all of the data, some is stored on the reel label or datasheet.
Application and Installation Conditions
- Fixed or moving installation.
- Minimum bend radius
- Temperature exposure
- Exposure to oil, chemical, moisture, abrasion or sunlight
- Cable tray, routing cabinet, conduit, drag chain routing or robotic routing
- Requirements for voltage, current, signal or communication
- Required certification market
The cable can be used only in the situation when both the marking and the usage conditions are identical.
Supplier Documentation
- Current technical datasheet
- Notification of certification or recognition.
- The UL Style or product standard documentation.
- Accurate records of reel label and delivery
- Test reports should be provided where appropriate.
- Details of the materials and construction.
- Records for revision and traceability
For applications that call for a non-standard construction, collaborate with a manufacturer that can offer the full engineering support involved in custom cable engineering support.
Cable Markings Are the Starting Point for Verification
Cable markings provide crucial identification and rating data, but more is needed. All of these make up the professional selection process, and it is essential that they all match up. When standard catalog items don’t have the right voltage, temperature, flex life, shielding and certification combination, a properly engineered custom solution is the sure route to go.
