NH-YJV Mica Tape Fire Resistant XLPE Cable
NH-YJV-0.6/1kV
Circuit integrity to 750 °C for 90 minutes without changing the XLPE installation method you already use.
Fire Resistant Cable
Fire resistant cable is defined by what it does during a fire, not after it: the circuit stays energised while the flame is applied. That behaviour comes from an inorganic barrier
Fire resistant cable is defined by what it does during a fire, not after it: the circuit stays energised while the flame is applied. That behaviour comes from an inorganic barrier — mica tape, magnesium oxide, a ceramic-forming compound — placed where a polymer would otherwise disappear. The standards differ in how harshly they test it: BS 6387 splits survival into fire alone (C), fire with water spray (W) and fire with mechanical shock (Z); BS 8491 applies all three at once; EN 50200 grades by duration as PH30 to PH120; GB/T 19216.21 holds 750 °C for 90 minutes with rated voltage applied.
The four constructions below reach comparable integrity ratings by different routes, and the right choice is usually made on installation rather than fire data. Rigid mineral insulated BTTZ gives the smallest diameter and the highest continuous temperature. Flexible BBTRZ pulls through conduit a rigid cable cannot enter. Aluminium-sheathed BTLY / NG-A is the middle option on weight and bend radius. NH-YJV keeps the familiar XLPE installation method and is the lowest installed cost of the four.
4 constructions in Fire Resistant Cable
BTTZ Mineral Insulated Copper Sheathed Cable
BTTZ-500V/750V
Magnesium oxide inside a copper tube: no organic material in the cable to burn.
BBTRZ Flexible Mineral Insulated Fire Resistant Cable
BBTRZ-0.6/1kV
Fire performance that clears BS 6387 C, W and Z without the handling penalty of a rigid copper tube.
BTLY / NG-A Aluminium Sheathed Mineral Insulated Cable
BTLY-0.6/1kV
A welded aluminium tube gives MI-class fire survival at a fraction of the sheath weight of copper.
Fire resistant vs fire retardant: what changes in the specification
The two terms are one letter apart and describe different tests. Fire resistant cable is energised during the fire test and must keep conducting; fire retardant cable is not energised and must simply stop the flame travelling. A specifier writing 'fire rated' into a bill of quantities without naming a standard will usually be supplied with the cheaper flame-retardant product, and the error surfaces only during a fire or during a commissioning inspection.
Link the choice to the function of the circuit. Anything that has to operate while people are still in the building — sprinkler and hydrant pumps, smoke extraction, evacuation lifts, emergency and escape lighting, fire detection and alarm loops, PA/VA evacuation systems, emergency shutdown valves — is fire resistant. Sub-main and final circuit cabling that merely shares the route is flame retardant, and bundling the two in one tray is normal practice.
- Fire resistant: circuit integrity under BS 6387, BS 8491, IEC 60331, EN 50200 or GB/T 19216
- Fire retardant: flame propagation under IEC 60332-1 or IEC 60332-3 categories A/B/C/D
- A cable can be both: WDZN-YJY is halogen-free, flame retardant and circuit-integrity rated
- State the duration that matches the evacuation and fire-brigade response strategy, not a round number
Reading BS 6387, BS 8491, IEC 60331 and EN 50200
BS 6387 tests three separate hazards and the result is quoted as a combination. Category C is fire alone at 950 °C for 180 minutes. Category W is fire at 650 °C followed by water spray, which is the realistic condition in a sprinklered building. Category Z is fire at 950 °C with mechanical shock applied at 30-second intervals, simulating falling debris and structural movement. A cable sold as 'CWZ' has cleared all three.
BS 8491 is the tunnel and metro reference: fire, water spray and mechanical shock are applied together in a single 120-minute test. EN 50200 uses a different flame protocol at 830 °C and grades the outcome by survival time — PH30, PH60, PH90, PH120 — with Annex E adding a water spray. IEC 60331 and its Chinese equivalent GB/T 19216.21 hold a lower flame temperature, typically 750 °C, but for 90 minutes with voltage applied throughout.
- BS 6387 C — 950 °C, 180 min, fire alone
- BS 6387 W — 650 °C, fire then water spray
- BS 6387 Z — 950 °C, fire with mechanical shock
- BS 8491 — fire, water and shock combined, 120 min
- EN 50200 — 830 °C, PH30 / PH60 / PH90 / PH120, Annex E for water
- GB/T 19216.21 / IEC 60331-21 — 750 °C or higher, 90 min, energised
Selecting between NH-YJV, BTTZ, BBTRZ and BTLY on site conditions
Because all four can be supplied to the same integrity category, the practical decision is mechanical and commercial. BTTZ has the smallest overall diameter — typically 25–30% less than a polymer fire-resistant cable — and a 250 °C conductor rating, but it is rigid, supplied in limited lengths, and every termination needs a pot seal. BBTRZ behaves like a flexible power cable at 6 × OD bending radius and needs no special tooling.
Look at the termination cost as well as the cable cost. On a 20-storey riser the labour difference between sealing forty BTTZ ends and crimping forty BBTRZ lugs can exceed the material difference. BTLY / NG-A sits between the two: lighter than copper-sheathed MI, stiffer than flexible mica cable, and requiring aluminium-compatible glands. NH-YJV is the choice when the installer already works to XLPE practice and the specification accepts 750 °C for 90 minutes.
- BTTZ — smallest OD, 250 °C continuous, rigid, sealed terminations, longest survival time
- BBTRZ — flexible, 6 × OD, standard lugs and glands, long drum lengths, no moisture sealing
- BTLY / NG-A — welded corrugated aluminium tube, light, 12 × OD, aluminium glands required
- NH-YJV — XLPE installation practice, mica barrier, lowest installed cost, 750 °C / 90 min
Request pricing across Fire Resistant 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
