NYM Cable

NYM cable is a European standard, PVC-sheathed installation cable designed for fixed wiring in buildings and industrial applications . Often referred to as NYM sheathed cable, building wire, or installation cable, it is the most widely used power cable for domestic, commercial, and light industrial electrical installations . The acronym "NYM" itself describes its construction: N for standardised cable (Normleitung), Y for PVC insulation, and M for sheathed cable (Mantelleitung)

Standards

DIN VDE 0250-204

NYM cable is manufactured to meet stringent German and European standards, ensuring safety and reliability. It complies with DIN VDE 0250-204 and is CE certified, conforming to the Low Voltage Directive . The cable is also flame retardant according to IEC 60332-1-2 and is available in CPR-compliant variants for construction products regulation . It is offered in two main types: NYM-J, which includes a green-yellow earth conductor, and NYM-O, which does not contain an earth core.

Construction

The construction of NYM power cable is specifically designed for fixed installation in harsh building conditions:

Conductor: Class 1 solid or Class 2 stranded bare copper conductors according to IEC 60228, ensuring secure terminations in junction boxes and panels .

Core Insulation: Each core is insulated with PVC (Polyvinyl Chloride) compound, with core identification according to VDE 0293-308 .

Inner Filler: An unique feature is the unvulcanised rubber filler or filler sheath surrounding the stranded cores, providing mechanical protection and circularity .

Outer Sheath: A tough PVC outer sheath (typically grey) provides protection against mechanical impact and moisture

Characteristics

Voltage Rated U0/ U: and 300/500V.

Note:

U0: Rated power-frequency voltage between conductor and earth for which the cable is suitable.

U: Rated power-frequency voltage between phase conductors for which the cable is suitable.

Maximum conductor operating temperature: +70℃

Maximum short circuit conductor temperature: +160℃

Test voltage: 2000V

Application

NYM applications are extensive in building installation. It is the standard choice for:

Fixed Wiring in Buildings: Installed in dry, damp, and wet premises, including under plaster, within brickwork, on cable trays, and in conduits .

Concrete Installation: It can be installed directly into concrete, but not in compacted, vibrated, or rammed concrete .

Domestic and Commercial Use: Power supply for lighting circuits, socket outlets, and fixed appliances in homes, offices, and industrial facilities .

Limitations: NYM is not suitable for outdoor use without additional UV protection, nor for direct burial in the ground

Specification