GMW 15626 Single Core Multistrand ISO Cable

The “GMW 15626 Single-core multistrand ISO cable” standard, published by General Motors (GM), describes the dimensions, test methods, and requirements for single-core copper cables. This standard is based on and refers to ISO 19642-1, ISO 19642-2, ISO 19642-3, and ISO 19642-5 standards.

This standard defines the testing and verification requirements for single-core copper cables. It also applies to individual cores in multi-core cables.

Single-core cables are classified according to the nominal voltage of the system in which the cables are used, the wall dimensions of the cable insulation, and the operating temperature.

The nominal system voltage class is defined as three cable classes for use in road vehicle applications, as given in the table entitled "Nominal system voltage value" within the standard:

• Voltage class 60V: Maximum operating voltage 60 DC or 30 AC.
• Voltage class 900V: Operating voltage between 60V and 900V DC or 30V and 600V AC.
• Voltage class 1500V: operating voltage between 60V and 1500V DC or 30V and 1000V AC

Temperature classes are defined in the standard's table titled "Temperature class rating" as eight cable classes corresponding to various temperatures encountered in vehicles:

• Temperature class A: Operating temperature between -40 and +85 degrees (T1)
• Temperature class B: Operating temperature between -40 and +100 degrees (T2)
• Temperature class C: Operating temperature between -40 and +125 degrees (T3)
• Temperature class D: Operating temperature between -40 and +150 degrees (T4)
• Temperature class E: Operating temperature between -40 and +175 degrees (T5)
• Temperature class F: Operating temperature between -40 and +200 degrees (T6)
• Temperature class G: Operating temperature between -40 and +225 degrees (T7)
• Temperature class H: Operating temperature between -40 and +250 degrees (T8)

In the high-risk world of automotive engineering, where every gram counts and reliability is non-negotiable, the evolution of wiring standards has played a crucial role in advancing vehicle performance and safety. General Motors' GMW 15626 standard, a cornerstone of modern electrical systems in vehicles, outlines the requirements for low-voltage, unshielded wiring designed to withstand the rigors of automotive environments. As electric vehicles and autonomous driving technologies rapidly evolve, the GMW 15626 standard ensures that the wiring for these machines remains robust, efficient, and future-proof.

The GMW 15626 standard emerged as part of GM’s broader suite of engineering standards. These standards are internal guidelines that suppliers must adhere to for components used in GM vehicles. GMW 15626 is aligned with the ISO 6722-1 standard framework for low-voltage automotive cabling for road vehicles, emphasizing multi-strand copper conductors for flexibility and durability.

The need for such a standard arose with the increasing demand for lighter and more efficient vehicles. Traditional cabling is cumbersome and heavy, contributing to fuel inefficiency and increased production costs. The GMW 15626 standard addresses this problem by specifying ultra-thin wall insulation and precision conductor compositions, reducing weight without compromising safety. Its introduction coinciding with the rise of hybrid and electric powertrains is no coincidence, as compact, heat-resistant cabling for battery management systems, sensors, and infotainment networks is essential in these areas.

The GMW 15626 standard defines single-core cables (i.e., one conductor per wire) that are essentially optimized for low-voltage applications (typically rated at 60 V). These cables are unshielded, making them ideal for internal circuit connections where electromagnetic interference is minimal.

The basic technical parameters are as follows:

• Conductor: Bare or tinned multi-strand copper (ISO compliant), providing high conductivity and flexibility. Typical values ​​are 0,35 mm² to 8,00 mm² cross-section, with 19-strand configurations being common for 1,5 mm².
• Insulation: Thin-walled or ultra-thin-walled materials for weight savings, options include PVC, PP, EVA, XLPO, PUR, TPE, SIR, ETFE, FEP or PFA. Typical ratings are R2/R3/R4/R6 types, halogen-free variants for environmental friendliness.
• Temperature range: Rated for extreme automotive conditions, from freezing cold to engine compartment temperatures. Typical values ​​are -40 degrees to +105 degrees (standard), up to +250 degrees for high-temperature variants like the PFA.
• Voltage rating: Low voltage design for safety in 12V/24V/48V systems. Typical values, nominal 60V AC/DC.
• Compliance: Meets or exceeds ISO 6722-1 standard, cross-referenced with GMW3173 standard for wiring harness requirements.

These features are not random; they have undergone rigorous testing in terms of characteristic features of a vehicle's lifecycle, such as wear resistance, exposure to chemicals (oils, fuels, coolants), and vibration. For example, the FL2X-A series (ultra-thin wall, 125-degree rated) is a popular model available in colors such as white or yellow for easy identification in wiring harnesses.

GMW 15626 cables are widely used across a very broad product range and form the backbone of power distribution and signal transmission. This standard has influenced GM as well as global suppliers of the standard.

• Electric vehicles: In battery packs and inverters, these cables handle high current flows with minimal voltage drop thanks to their low-resistance copper cores.
• Engine compartments: Heat-resistant variants (e.g., cross-linked PE insulation) withstand temperatures up to 150 degrees.
• Internal circuits: Thinner insulation reduces bundle diameters, saving space in instrument panels and doors for advanced driver assistance systems.

This standard's eco-friendly options, such as low-halogen or halogen-free insulation, also support sustainability goals by minimizing toxic emissions, which are critical for electric vehicle safety in the event of a fire.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "GMW 15626 Single-core multi-strand ISO cable" standard.