NYA Cables Selection Guide
NYA is an unsheathed cable and covers H05V-U, H07V-U or H07V-R depending on cross-section; cross-section, color and place of use decide the selection.
This guide explains what to look at when choosing products in the NYA Cables category.
H05V-U, H07V-U and H07V-R: the code changes with cross-section
The name NYA does not denote a single cable; it covers three harmonized types depending on cross-section. In the HES Kablo datasheet the distinction is as follows:
- 1 mm² and below: H05V-U, solid conductor, rated voltage 300/500 V.
- 1.5 mm² to 10 mm²: H07V-U, solid conductor, 450/750 V.
- 10 mm² and above: H07V-R, stranded (braided) rigid conductor, 450/750 V. 10 mm² is made in both constructions.
For small and large cross-sections, confirm the conductor construction and rated voltage from the product datasheet. The maximum operating temperature in the datasheet is 70 °C.
Where it is used and where it is not
NYA is unsheathed; there is no second layer over the insulation to protect against impact and moisture. The manufacturer datasheet defines the place of use as dry locations inside buildings, in conduit under or on plaster; it is also used in cable trunking inside enclosures. For runs that will be laid in the open, without conduit or underground, look at the sheathed types: NYM antigron cables for fixed installation inside buildings, and NYY cables for underground and cable trunking.
Choosing cross-section and color
Three things determine the cross-section: the load current of the circuit, the voltage drop depending on line length, and the number of loaded conductors passing through the same conduit. As the number of conductors in the conduit increases and the environment warms up, the current each conductor can carry decreases. You can pre-check the load current with the current and fuse calculation from active power tool, and the cross-section with the cable current carrying capacity calculation and voltage drop calculation tools; the exact cross-section is determined by the project calculation.
Color shows the function of the conductor. In the IEC conductor color rule, yellow-green is only for the protective (earthing) conductor, and the neutral conductor is blue; the preferred colors for phase conductors are brown, black and gray. Red is not among these preferred phase colors; in which circuit it is used depends on the project and the facility's color code. Large cross-section yellow-green NYA is used for enclosure and facility earthing connections.
Difference between NYA, NYAF and halogen-free NYA
- NYAF (H07V-K): NYAF cables carry the same insulation, but the conductor is finely stranded; at the same cross-section the outer diameter and resistance are slightly higher. Rigid NYA is connected to a screw terminal block without a ferrule and can be pushed through short conduit runs; NYAF makes wiring easier in tight-bend enclosure wiring.
- Halogen-free NYA (H07Z1-U/R): NYA halogen-free cables have the same conductor construction, but the insulation is a halogen-free compound. It is chosen instead of PVC-insulated NYA in buildings where low smoke and low corrosive gas are wanted in a fire.
Brands in this category
HES Kablo, Nexans, Prysmian, Ünal Kablo, Koç Kablo and Öznur Kablo list single-core NYA in this category with cross-section and color options. In Ünal product names, large cross-sections appear with the H07V-R code, and Öznur's yellow-green products appear under the name earthing cable.
Order notes
- NYA is sold per meter; each cross-section and color is a separate product.
- For items listed as made to order, the lead time is confirmed before ordering.
NYA (H07V-U / H07V-R) cross-section and installation table
| Cross-Section | Conductor Structure | Typical Protection | Fixed Installation Application | Cross-Section Page |
|---|---|---|---|---|
| 1x1.5 mm² | Solid copper (H07V-U, Class 1) | 10 A Type B/C MCB | Fixed lighting circuits and switch return wires inside conduits | 1x1.5 mm² NYA Cables |
| 1x2.5 mm² | Solid copper (H07V-U, Class 1) | 16 A Type B/C MCB | Socket-outlet branch circuits and fixed appliance feeds in conduits | 1x2.5 mm² NYA Cables |
| 1x4 mm² – 1x10 mm² | Solid or stranded copper (H07V-U / H07V-R) | 25 A – 50 A MCB | Sub-distribution consumer unit feeders, ovens, and earthing conductors | 1x6 mm² NYA Cables |
| 1x16 mm² – 1x300 mm² | Stranded copper (H07V-R, Class 2) | 63 A+ MCCB / fuse | Main riser columns, equipotential bonding, and closed trunking feeders | 1x16 mm² NYA Cables |
Frequently asked questions
How many amperes does a 4 mm² NYA cable carry?
There is no single value; the result depends on the installation method. The HES datasheet gives 42 A in air at a 30 °C ambient temperature for 4 mm² NYA. NYA, however, is used inside conduit, mostly together with other loaded conductors, and in that case the current it can carry is noticeably below this value. The fuse rated current is taken not from the highest value in the table but from the project calculation.
Can NYA cable be used without conduit, in the open or underground?
The manufacturer datasheet defines the place of use of NYA as dry locations inside buildings and in conduit under or on plaster. Because the cable is unsheathed, its insulation has no second layer protecting it against external influences. The sheathed type defined for flush-mounted and surface-mounted fixed installation is NYM, and the type defined for underground and cable trunking is NYY in the 0.6/1 kV class.
What is the difference between H07V-U and H07V-R?
Both are 450/750 V class, PVC-insulated, single-core unsheathed cables; the difference is in the conductor. U indicates a solid conductor, and R a stranded rigid conductor formed by braiding several wires. In the HES datasheet, cross-sections up to 10 mm² are made with a solid conductor and cross-sections of 10 mm² and above with a stranded one. Both are referred to as NYA on the market.
Can NYAF be used instead of NYA?
The insulation of the two cables and the rated voltage at the same cross-section are the same; the HES datasheets give the same current values for cross-sections of 1.5 mm² and above. The difference is in the conductor: because NYAF is finely stranded, it is mostly connected to a screw terminal block with a ferrule, and its outer diameter and resistance are slightly higher. The type of the connection points and the bend of the route decide the choice; if the project calls for a specific type, follow it.
What do the colors mean on NYA cable?
Yellow-green is used only for the protective (earthing) conductor; blue is the color of the neutral conductor. In the IEC conductor color rule, the preferred colors for phase conductors are brown, black and gray. Red is not among these preferred colors; in facilities where it is used, its meaning depends on that facility's color code. Color assignment is made according to the project and the regulation in force.