CableDataSheet, Cable and Wire Technical Consulting Service

What is Paint-Wetting Impairment Substances (PWIS) ?

Paint-Wetting Impairment Substances (PWIS)

Examples of such substances are oils, greases, fluoride, waxes and silicone.

They negatively affect painting processes and are not allowed in the automotive industry and other production plants.

A thin oil-film is usually present on the steel coils we purchase and additional lubrication is often necessary for the roll-forming and stamping processes.

The protective foil of several self-adhesive gaskets also contains some silicone (see also the additional information ZI-201, 202, 206, 210, ...).

In view of the above we cannot guarantee that our products are totally PWIS-free

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How to calculate the tin quantity on a copper wire g/m2 ?

Measure the length of the copper wire using a ruler or measuring tape and record the length in meters.

Cut a representative sample of the copper wire.

Weigh the sample of the copper wire using a precise balance and record its mass in grams.

Immerse the sample in a suitable solution that selectively dissolves the tin coating while leaving the copper unaffected. Nitric acid is commonly used for this purpose.

Allow the sample to remain in the solution for a specific duration to ensure complete dissolution of the tin coating. The duration may vary depending on the thickness of the tin coating and the concentration of the solution. Follow the instructions and guidelines for the specific solution being used.

After the appropriate time has passed, remove the sample from the solution and rinse it thoroughly with water to remove any traces of the solution. ( For the hydrochloric acid electrolyte, dilute 170 ml of hydrochloric acid (HCI), p = 1,18 g/ml, to 1 000 ml with deionised water.)

Dry the sample carefully to remove any remaining moisture.

Weigh the sample again using the precise balance and record its mass in grams.

Calculate the mass of the tin coating by subtracting the final mass of the sample (after tin dissolution) from the initial mass of the sample (before tin dissolution).

Calculate the surface area of the copper wire sample. For a cylindrical wire, you can use the formula:
Surface Area = 2πrL

Here, r represents the radius of the wire (which can be obtained from the wire diameter), and L represents the length of the wire.

Divide the mass of the tin coating by the surface area to obtain the tin quantity in grams per square meter (g/m²):
Tin Quantity (g/m²) = Mass of Tin Coating (grams) / Surface Area (m²)
For example, let's say you have a copper wire sample with an initial mass of 10 grams, a length of 1 meter, and a diameter of 0.5 mm. First, calculate the radius by dividing the diameter by 2: 0.5 mm / 2 = 0.25 mm = 0.00025 meters.

Next, calculate the surface area of the wire using the formula:
Surface Area = 2π(0.00025)(1) = 0.00157 m²

Finally, divide the mass of the tin coating by the surface area to find the tin quantity in g/m²:
Tin Quantity (g/m²) = 10 grams / 0.00157 m² ≈ 6369.43 g/m²

Thus, the tin quantity on the copper wire sample is approximately 6369.43 g/m².

Hi, we are attempting to design a small lab scale stranding machine for the production of small quantities of cabled enamelled copper wire.

A typical cable construction consists of 8x0.236mm strands around a center 0.5mm conductor. All cores are enamelled to IEC 60317-14 to provide a multi-conductor cable. Some other designs are more Litz-like with multiple bundles of 0.1mm wire twisted in hierarchical fashion (type 2 and 3 Litz wire).

We have investigated various designs for stranding machine that could be scaled down to a bench top unit suitable for a lab. One area that is causing particular confusion is that of back-twist and how it relates to the construction of stranded electrical cables. I have seen industrial scale rigid frame and planetary stranding machines, but am confused about what would be the best choice for building our target cables.

Could someone explain the purpose of back-twist and its effects on the cable's properties and how these relate to the design of a planetary stranding machine.

What is the Difference Between Dry, Wet, and Damp Locations?

(NEC) National Electric Code Definitions: UL Standard 1598 Definitions:

Dry Locations: A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.

Damp Location: Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture. Examples of such locations include partially protected locations
under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderated degrees of moisture, such as some basements, some barns, and some cold storage buildings.

Wet Locations: Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as in vehicle washing areas; and in
unprotected locations exposed to the weather.


UL Standard 1598 Definitions:


Dry Locations: A location not normally subject to dampness, but may include a location subject to temporary dampness, as in the case of a building under construction, provided ventilation is adequate to prevent
an accumulation of moisture.

Damp Location: An exterior or interior location that is normally or periodically subject to condensation of moisture in, on, or adjacent to, electrical equipment, and includes partially protected locations.

Wet Locations: A location in which water or other liquid can drip, splash, or flow on or against electrical equipment. A wet location luminaire shall be constructed to prevent the accumulation of water on live parts, electrical components, or conductors not identified for use in contact with water. A luminaire that permits water to enter the luminaire (during the rain test of Clause 16.5.2 or the sprinkler test of Clause 16.5.3) shall be provided with a drain hole (Clause 13.4.3).

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Elements of the IP Code and their meanings

A brief description of the IP Code elements is given in the following chart (see Fig. E67).

What is the external influences IEC 60364-5-51 ?

Each condition of external influence is designated by a code comprising a group of two capital letters and a number as follows:

First letter (A, B or C)

The first letter relates to the general category of external influence:

    A = environment
    B = utilisation
    C = construction of buildings

Second letter

The second letter relates to the nature of the external influence.
Number

The number relates to the class within each external influence.
Additional letter (optional)

Used only if the effective protection of persons is greater than that indicated by the first IP digit.

When only the protection of persons is to be specified, the two digits of the IP code are replaced by the X's.

Example: IP XXB.

Example

For example the code AC2 signifies:

A = environment
AC = environment-altitude
AC2 = environment-altitude > 2,000 m













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Flat cables twisting problems and solutions

If you want less rotation, the winding angle should be narrow.

501.10(B)(1) Wiring Methods. Class I, Division 2.,

Code Change Summary: Changes were made to the allowable wiring methods used in a Class I Division 2 location.

Article 501 is all about Class I hazardous locations. The Class represents the type of flammable material, whereas the Division represents the conditions where the flammable materials are used or stored and the likelihood of the flammable material being present.

Examples of Class I locations include fuel dispensing, spray booths where volatile flammable solvents are used, gas generator rooms and other portions of gas manufacturing plants where flammable gas may escape.

Section 501.10(A) specifies all of the types of wiring methods permitted to be used in a Class I Division 1 hazardous location. Those methods are also permitted to be used in a Class I Division 2 location which is less restrictive than a Division 1 location. Two of the allowable wiring methods for a Class I Division 1 location are threaded rigid metal conduit (RMC) and threaded steel intermediate metal conduit (IMC).

In the 2017 NEC, revisions were made to 501.10(B), pertaining to Class I Division 2 locations, to allow RMC and IMC with listed threadless fittings. Requiring only threaded fittings as in 501.10(A) was too restrictive since many cable types permitted in Class I Division 2 locations were only required to use listed fittings. Many listed cable fittings are threadless and permitted in Class I Division 2 locations.

Another change was the addition of Cablebus to the permitted wiring methods in a Class I Division 2 location. Cablebus is similar to cable tray with spacers between the conductors. Since tray cable is allowed in a Class I, Division 2 location, there is no reason a cablebus with insulated cables shouldnt also be allowed.

Below is a preview of the NEC. See the actual NEC® text at You are not allowed to view links. Register or Login for the complete code section. Once there, click on their link to free access to the 2017 NEC® edition of NFPA 70.

2014 Code Language: 501.10(B) Class I, Division 2.

(1) General. In Class I, Division 2 locations, the following wiring methods shall be permitted:

(1) All wiring methods permitted in 501.10(A).

(2) Enclosed gasketed busways and enclosed gasketed wireways.

(3) Type PLTC and Type PLTC-ER cable (see NEC® text for remainder).

(4) Type ITC and Type ITC-ER cable as permitted in 727.4 and terminated with listed fittings.

(5) Type MC, MV, TC, or TC-ER cable (see NEC® text for remainder).

(6) In industrial establishments with restricted public access (see NEC® text for remainder).

(7) Optical fiber cable Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC (see NEC® text for remainder).


2017 Code Language:501.10(B) Class I, Division 2.

(1) General. In Class I, Division 2 locations, all wiring methods permitted in 501.10(A) and the following wiring methods shall be permitted:

(1) Rigid metal conduit (RMC) and intermediate metal conduit (IMC) with listed threadless fittings.

(2) Enclosed gasketed busways and enclosed gasketed wireways.

(3) Type PLTC and Type PLTC-ER cable in accordance with the provisions of Article 725, including installation in cable tray systems. The cable shall be terminated with listed fittings.

(4) Type ITC and Type ITC-ER cable as permitted in 727.4 and terminated with listed fittings.

(5) Type MC, MV, TC, or TC-ER cable, including installation in cable tray systems. The cable shall be terminated with listed fittings.

(6) In industrial establishments with restricted public access (see NEC® text for remainder).

(7) Optical fiber cable Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC (see NEC® text for remainder).

( Cablebus.

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