Low Voltage Cables Selection Guide
Engineering guide to choosing NYA, NYAF, NYM, TTR, NYY, N2XH and aluminum NAYY/NA2XH low-voltage power cables by ampacity, insulation and fire performance.
What are low voltage cables? Low voltage cables are 300/500 V, 450/750 V, and 0.6/1 kV power and installation cables used for building wiring, switchgear panel interconnections, underground mains feeders, and industrial power distribution.
This guide explains how to select cables in the Low Voltage Cables category. For sizing calculations, use the Cable Ampacity Calculator and Voltage Drop Calculator.
Main low voltage cable groups
- NYA cables and NYA halogen-free cables: Rigid single-core conduit wires (H07V-U/R and H07Z1-U/R) for fixed building installations.
- NYAF cables and NYAF halogen-free cables: Fine-stranded flexible single-core wires (H07V-K / H07Z1-K) for internal electrical panel wiring.
- NYM antigron cables and NHXMH cables: Sheathed multi-core installation cables for surface, flush, and damp-area building wiring.
- TTR cables and TTR halogen-free cables: Flexible multi-core cords (H05VV-F) for appliances, portable tools, and extension leads.
- NYY cables, N2XH cables, and N2XH FE180 cables: 0.6/1 kV main distribution and underground feeder cables, including FE180 fire-resistant variants.
- NAYY aluminum cables and NA2XH aluminum cables: Large-cross-section aluminum-conductor feeder cables.
Cable comparison table
| Cable Type | Voltage Rating | Conductor & Insulation | Jacket Type | Typical Application |
|---|---|---|---|---|
| NYA (H07V-U/R) | 450/750 V | Solid/stranded Cu, PVC | PVC or LSZH | Fixed conduit wiring for lighting and sockets |
| NYAF (H07V-K) | 450/750 V | Flexible fine-stranded Cu | PVC or LSZH | Control cabinet wire ducts and switchgear wiring |
| NYM / NHXMH | 300/500 V | Multi-core Cu | PVC (NYM) / LSZH (NHXMH) | Surface-mounted and damp-location fixed installations |
| TTR (H05VV-F) | 300/500 V | Flexible multi-core Cu | PVC or LSZH | Portable appliances, extension cords and light machinery |
| NYY | 0.6/1 kV | Cu, PVC insulation (70 °C) | Black PVC | Direct burial, outdoor trenches and cable ducts |
| N2XH | 0.6/1 kV | Cu, XLPE insulation (90 °C) | Halogen-free (LSZH) | Hospitals, malls, hotels and high-occupancy risers |
Frequently asked questions
What is the difference between NYY and N2XH power cables?
Both are 0.6/1 kV distribution cables, but NYY uses PVC insulation (70 °C max conductor temperature) and a PVC sheath for outdoor/underground runs. N2XH uses cross-linked polyethylene (XLPE) insulation (90 °C operating temperature, giving higher current capacity for the same cross-section) and a low-smoke zero-halogen (LSZH) jacket required in public buildings.
Why is NYAF preferred over NYA inside electrical panels?
NYAF has a Class 5 fine-stranded flexible copper conductor that bends easily through tight panel wire ducts and terminates cleanly with cable ferrules, whereas NYA is rigid.
How should aluminum NAYY or NA2XH cables be terminated onto copper busbars?
Always use bimetal cable lugs (friction-welded aluminum barrel to copper palm) to prevent galvanic corrosion at the aluminum-to-copper joint.