Underground cable NYY-J 25 mm²
Buy at B2B prices
Apply for a B2B account for wholesale prices.
0% VAT for B2B customers from Belgium, Austria, and the Netherlands.
Subscribe to the newsletter to receive the latest discount codes.
5% discount for orders over €500
Subscribe to the Newsletter, to receive the code.
Free shipping to Germany
for orders over €500 without freight forwarding
and for all orders over €1000
NYY-J 25mm² Underground Cable – Premium Direct Burial PVC Power Cable for 0.6/1 kV Installations
The NYY-J 25mm² cable (also known as 25mm² underground cable, direct burial power cable, 25 sq mm earth cable, or NYY-J 1x25 RM) is a robust single-core copper conductor PVC-insulated and sheathed power cable designed for safe, long-term fixed installations. Manufactured to VDE 0276-603 and HD 603 standards, this low-voltage (0.6/1 kV) cable is the preferred choice for professional electricians, electrical service companies, construction firms, renovation contractors, industrial operators, research centers, van conversion specialists, and B2B buyers across Europe.
Technical Specifications – NYY-J 25mm² Cable
Key data for the standard NYY-J 1x25 RM variant (Class 2 stranded bare copper conductor) – trusted by engineers and installers:
| Parameter | Specification |
|---|---|
| Conductor Cross-Section | 25 mm² (1x25 mm² with green/yellow protective earth conductor) |
| Conductor Material | Bare copper, Class 2 stranded (RM) |
| Insulation & Sheath | PVC (flame-retardant according to IEC 60332-1) |
| Outer Sheath Color | Black |
| Nominal Voltage (U₀/U) | 0.6 / 1 kV |
| Test Voltage | 4 kV |
| Approx. Outer Diameter | 13 mm (for 1x25 RM version) |
| Max. Conductor Operating Temperature | +70 °C (continuous) |
| Installation Temperature Range | -5 °C to +50 °C |
| Current Carrying Capacity (direct burial in ground, 20 °C soil) | Approx. 138 A (per VDE/HD 603 tables) |
| Current Carrying Capacity (in air, 30 °C) | Approx. 114 A |
| Max. Conductor Resistance (at 20 °C) | 0.727 Ω/km |
| Standards & Approvals | VDE 0276-603, HD 603 S1, IEC 60502-1, CE marked |
Professional Applications of NYY-J 25mm² Underground Cable
This versatile direct burial cable excels in demanding environments where reliable power distribution is essential. It is widely used by:
- Electrical contractors and service companies for underground mains supply to buildings and distribution boards
- Construction and infrastructure projects requiring robust earth and strong current cables
- Industrial facilities for fixed power feeds to machinery and heavy equipment
- Renovation and retrofit projects upgrading existing underground networks
- Renewable energy installations (solar PV farm connections and inverter links)
- EV charging station infrastructure with high-current underground routing
- Van conversions and campervan electrical systems needing durable 25mm² cabling
- Research centers and laboratories for compliant low-voltage power distribution in soil, concrete, or water (where mechanical damage is not expected)
Its direct-burial capability often eliminates the need for extra protective conduits, reducing installation time and costs on large-scale B2B projects while meeting strict safety requirements.
Why Professionals Choose NYY-J 25mm² Cable
With excellent conductivity, low voltage drop, UV and chemical resistance, and proven long service life, this PVC underground cable offers outstanding value for money. It combines VDE compliance with cost-effective bulk purchasing – ideal for electrical service providers, construction companies, industrial buyers, and renovation specialists seeking reliable performance and full technical documentation.
Frequently Asked Questions (FAQ) – NYY-J 25mm² Underground Cable
What does NYY-J mean?
NYY-J is the European/German designation for a PVC-insulated and sheathed power cable (N = normative/standardised, Y = PVC insulation and sheath) with an integrated protective earth conductor (J = green/yellow). It is specifically designed as a direct burial underground cable for fixed installations.
What is the outer diameter of NYY-J 25mm² cable?
Approximately 13 mm for the standard 1x25 RM single-core version. Always confirm with the manufacturer’s current datasheet for your specific batch.
Is NYY-J 25mm² suitable for direct burial?
Yes. It is approved for direct burial in the ground (minimum depth typically 0.6–0.8 m depending on location) without additional armouring, provided mechanical damage is unlikely. Suitable for soil, concrete, and water in many cases.
What is the current carrying capacity of a 25mm² NYY-J cable?
Approximately 138 A when directly buried in ground (20 °C soil temperature) and around 114 A when installed in free air (30 °C ambient). Values depend on installation method, grouping, and ambient conditions – always refer to VDE 0298-4 tables.
Is the NYY-J 25mm² cable halogen-free?
No. Standard NYY-J cables use PVC, which contains halogens. For low-smoke zero-halogen (LSZH) alternatives, consider FR-NHX or similar cables.
Can NYY-J 25mm² be used for solar or EV charging installations?
Yes. It is commonly used for underground power feeds in solar PV systems and as supply cables to electric vehicle charging stations where high current and direct-burial capability are required.
What is the difference between NYY-J and NYY-O?
NYY-J includes a green/yellow protective earth conductor for safety compliance. NYY-O does not have this dedicated earth core. Most professional installations prefer the NYY-J version.
Who typically buys NYY-J 25mm² cable in bulk?
Professional electricians, electrical service companies, construction firms, renovation contractors, industrial companies, research centers, van conversion builders, and B2B wholesalers looking for competitive meterware pricing and fast delivery.
For expert technical advice, bulk pricing, custom lengths, or full documentation, contact our B2B team. We support large-scale projects across Germany, Austria, and beyond with reliable service and competitive conditions.