NH-YJV-0.6/1kV
NH-YJV Mica Tape Fire Resistant XLPE Power Cable
Circuit integrity to 750 °C for 90 minutes without changing the XLPE installation method you already use.
Fire resistant cable has one job that flame-retardant cable cannot do: keep the circuit closed while the fire is still burning. NH-YJV puts a phlogopite mica glass tape directly over the stranded copper conductor before the XLPE is extruded. When the polymer layers burn away, the mica remains as a coherent tube around each conductor, so the insulation path between cores and to earth survives long enough for a sprinkler pump, smoke fan or evacuation lift to finish its work.
Voltcore applies two tape layers at not less than 25% overlap and verifies the result to GB/T 19216.21 at 750 °C for 90 minutes with rated voltage applied. Where the project names BS 6387, the same construction is submitted for category C at 950 °C for 180 minutes, W with water spray and Z with mechanical shock. Core colours, gland bores and lug sizes follow normal XLPE practice, so the installation method on site does not change.
Specification
| Item | Value |
|---|---|
| Rated voltage U0/U | 0.6/1 kV (6/10 kV and 8.7/15 kV on request) |
| Conductor | Plain annealed copper, Class 2 stranded, IEC 60228 |
| Fire barrier | Two layers phlogopite mica glass tape, minimum 25% overlap |
| Insulation | XLPE, 90 °C continuous, 250 °C short-circuit (≤ 5 s) |
| Number of cores | 1, 2, 3, 4, 5, 3+1, 3+2, 4+1 |
| Cross-section range | 1.5 – 630 mm² (multi-core up to 300 mm²) |
| Sheath | PVC compound type ST2, black (LSZH option: NH-YJY) |
| Circuit integrity | GB/T 19216.21 at 750 °C for 90 min; BS 6387 C/W/Z on request |
| Flame propagation | IEC 60332-1 single cable, IEC 60332-3-24 category C bunched |
| Min bending radius | 15 × OD unarmoured, 12 × OD for NH-YJV22 |
| Installation temperature | Not below 0 °C without pre-heating |
Layer-by-layer construction
Listed from the conductor outward. Read this alongside the specification table — the two together tell you whether the cable will survive its installation method.
- 1. ConductorClass 2 stranded plain annealed copper, IEC 60228
- 2. Fire barrierTwo layers phlogopite mica glass tape, minimum 25% overlap, applied per conductor
- 3. InsulationXLPE, colour-coded, 90 °C continuous rating
- 4. Filler and beddingNon-hygroscopic polypropylene filler with a binder tape over the laid-up cores
- 5. Outer sheathPVC type ST2, black, flame retardant to IEC 60332-3-24
Reference dimensions and weights
| Nominal cross-section (mm²) | Conductor structure (n × mm) | Insulation thickness (mm) | Approx. overall diameter (mm) | Approx. weight (kg/km) | Max. DC resistance at 20 °C (Ω/km) |
|---|---|---|---|---|---|
| 4 × 2.5 | 7 / 0.67 | 0.7 | 13.9 | 265 | 7.41 |
| 4 × 4 | 7 / 0.85 | 0.7 | 15.2 | 350 | 4.61 |
| 4 × 6 | 7 / 1.04 | 0.7 | 16.6 | 455 | 3.08 |
| 4 × 10 | 7 / 1.35 | 0.7 | 19.6 | 690 | 1.83 |
| 4 × 16 | 7 / 1.70 | 0.7 | 22.2 | 1010 | 1.15 |
| 4 × 25 | 7 / 2.14 | 0.9 | 26.2 | 1520 | 0.727 |
| 4 × 35 | 7 / 2.52 | 0.9 | 29.4 | 2020 | 0.524 |
| 4 × 50 | 19 / 1.78 | 1.0 | 33.8 | 2770 | 0.387 |
| 4 × 70 | 19 / 2.14 | 1.1 | 38.2 | 3780 | 0.268 |
| 4 × 95 | 19 / 2.52 | 1.1 | 42.8 | 4980 | 0.193 |
Reference figures for preliminary sizing and drum planning. Overall diameter and weight vary with strand construction and sheath thickness tolerance; certified drawings are issued with each quotation.
Engineering characteristics
- Double-layer phlogopite mica tape over each conductor holds insulation resistance at 750 °C for 90 min under GB/T 19216.21.
- XLPE insulation rated 90 °C continuous and 250 °C short-circuit for up to 5 s, so ampacity is not derated against standard YJV.
- PVC ST2 sheath limits flame spread to IEC 60332-1 and IEC 60332-3-24 category C on vertical trays.
- Class 2 copper to IEC 60228: 4.61 Ω/km maximum at 4 mm² falling to 0.193 Ω/km at 95 mm², measured at 20 °C.
- The mica barrier sits under the insulation on each core, so a single tape defect cannot bridge two phases.
- Minimum bending radius 15 × OD unarmoured, 12 × OD for the armoured NH-YJV22 version, installed at 0 °C or above.
- LSZH-sheathed NH-YJY variant available where the route passes through occupied escape corridors.
Typical applications
- Sprinkler and hydrant pump feeders in high-rise and industrial buildings
- Smoke extraction and stairwell pressurisation fan circuits
- Evacuation lift and fire lift power supplies
- Emergency lighting and fire alarm distribution boards
- Generator to essential-services board links in hospitals and metro stations
- Fire pump rooms and risers in petrochemical and power plant buildings
Ordering options
- NH-YJV22 — double steel tape armoured for direct burial and outdoor riser routes
- NH-YJY and NH-YJY23 — LSZH sheath for tunnels and occupied escape routes
- 6/10 kV and 8.7/15 kV constructions for fire pump feeders on MV distribution
- Tinned copper conductors and red sheath printing for fire service identification
- Cut-to-length riser sets with numbered tags per floor
Standards manufactured to
- GB/T 19216.21
- IEC 60331-21
- BS 6387 (C/W/Z on request)
- IEC 60502-1
- GB/T 12706.1
- IEC 60332-3-24
- IEC 60228
Manufactured to other standards on request. Send the standard number with your RFQ and we will quote against it rather than against a near-equivalent.
Price and availability for NH-YJV Mica Tape Fire Resistant XLPE Cable
Include cross-section, core count, voltage grade, route length and installation method — those five determine price more than anything else on the page.
- Engineer-reviewed before pricing
- Reference drawings issued with the quotation
- Free sample up to free sample up to 5 m
NH-YJV Mica Tape Fire Resistant XLPE Cable — frequently asked questions
What is the difference between fire resistant cable and fire retardant cable?
Fire resistant cable is tested with the circuit energised and must keep conducting while the flame is applied, to GB/T 19216.21, BS 6387 or EN 50200. Fire retardant cable is not energised; it only has to self-extinguish once ignited, tested to IEC 60332-3. A fire pump needs the first. A general power feeder sharing the same tray usually needs only the second.
Can NH-YJV replace standard YJV one for one in an existing tray?
Ampacity is unchanged, because conductor size, insulation thickness and the 90 °C rating are the same. Overall diameter runs about 4–7% larger from the mica layers and weight about 6–9% higher, so check tray fill, gland bore and cleat spacing. On long vertical runs the extra mass is what usually forces a closer cleat pitch rather than any electrical limit.
How long does the circuit survive and at what temperature?
Under GB/T 19216.21 the sample carries rated voltage in a flame of at least 750 °C for 90 minutes with no fuse operation and no conductor break. Where BS 6387 is specified, category C raises that to 950 °C for 180 minutes, W adds a water spray and Z adds repeated mechanical shock. A third tape layer is available for 180-minute GB/T durations.
Does a fire resistant cable need armouring?
Only for mechanical protection. Armouring does not improve circuit integrity, but it does stop impact or crushing from severing the circuit before a fire starts. Choose NH-YJV22 for direct burial, outdoor risers and routes exposed to vehicles or falling debris; NH-YJV is sufficient inside a tray or conduit that is itself fire rated.