N-DJYP3V22 Steel-Wire Armored Fire-Resistant Computer & Instrumentation Cable
A fire breaks out in a petrochemical refinery at 3 AM. Standard control cables fail within minutes. Signal loss triggers a cascading system collapse before emergency shutdown protocols can activate. The financial damage isn’t just in repairs—it’s in weeks of unplanned downtime and regulatory fines.
The N-DJYP3V22 cable is engineered to prevent this sequence. Constructed with mica tape fire-resistant layers, a polyethylene insulated twisted-pair core, and a galvanized steel wire armor, this cable sustains circuit integrity during direct flame exposure. It buys time for controlled shutdowns, personnel evacuation, and asset protection. This means lower total risk exposure for your project and a verifiable compliance trail for fire safety audits.
Signal Integrity Under Fire: The Mica Tape Difference
Standard XLPE or PVC insulation collapses when charred. Mica tape does not. Wrapped directly around the copper conductor, it forms a non-conductive mineral barrier that maintains dielectric strength even after the organic layers above it burn away.
Mica Glass Tape Fire Barrier
Insulation resistance remains stable at temperatures exceeding 750°C. Your DCS and SCADA panels continue receiving data during the critical first 30 to 90 minutes of a fire event. No signal blackout during emergency shutdown sequencing.
Double-Layer Shielding: Aluminum-Polyester Tape + Tinned Copper Drain Wire
This provides comprehensive defense against electromagnetic interference (EMI) and capacitive coupling between adjacent pairs. Low-frequency interference from VFDs, motors, and switchgear gets shunted to ground. High-frequency noise gets reflected. The result is clean 4-20 mA analog signals and error-free RS-485 digital communication, even when cables are bundled in high-density trays alongside power feeders.
Galvanized Steel Wire Armor (SWA)
Polyethylene inner sheath separates the shielded core from the armor layer, preventing mechanical stress transfer. The SWA then absorbs crushing loads, direct impacts, and the tensile forces of cable pulling during installation. In service, it deters rodents and provides a low-impedance path to ground. You avoid replacing cables in concrete-embedded conduits or underground ducts—a cost no one budgets for.
Technical Specifications & Dimensions
| Parameter | Specification |
|---|---|
| Model Designation | N-DJYP3V22 |
| Conductor Material | Annealed Copper, Class 1 or Class 2 Stranded (per IEC 60228) |
| Fire-Resistant Layer | Mica Glass Tape, ≥ 20% overlap, synthetic mica for ≥ 750°C service |
| Core Insulation | Polyethylene (PE), color-coded or numbered pairs |
| Pair Twisting | Two insulated conductors twisted to precise lay lengths; pairs individually shielded |
| Individual Pair Shield | Aluminum-polyester tape, metallized side in contact with drain wire |
| Drain Wire | Tinned Copper, multi-strand |
| Pair Assembly | Shielded pairs cabled in concentric layers with non-hygroscopic fillers |
| Collective Wrapping | Polyester tape binder(s) |
| Inner Sheath | Black Polyethylene (PE) or PVC, extruded to compact the core |
| Armor | Galvanized Steel Wire (SWA), helical lay |
| Outer Sheath | Black PVC, UV- and oil-resistant compound |
| Rated Voltage (U₀/U) | 300/500 V |
| Test Voltage (Core-Core, 1 min) | 2000 V |
| Test Voltage (Core-Shield, 1 min) | 2000 V |
| Operating Temperature Range | -30°C up to +70°C (fixed installation) |
| Minimum Bending Radius | 12× overall cable diameter (single bend); 10× (fixed installation) |
| Fire Integrity (IEC 60331-21) | 750°C, 90 minutes at rated voltage |
| Flame Retardance (IEC 60332-3-22) | Category A (bunched cable vertical tray) |
| Smoke Density (IEC 61034) | > 60% light transmittance (low-smoke version available) |
| Halogen Acid Gas Emission (IEC 60754-1/2) | Available with LSZH outer sheath on request |
Industry Applications & Scenario Validation
- Petrochemical Processing Plants. Continuous gas detection and valve control signals inside fire-hazard zones. This cable maintains the ability to remotely isolate process streams during a fire, preventing uncontrolled hydrocarbon release.
- Tunnel Ventilation & Metro Infrastructure. Longitudinal ventilation fan control and evacuation signage in road/rail tunnels with extreme humidity and fire exposure risk. Steel wire armor withstands the water curtain and mist environment during fire suppression.
- Power Generation (Thermal & Nuclear Balance of Plant). Cable spreading rooms and cable cellars where flame propagation along trays is the primary design concern. Category A flame retardance prevents vertical fire jump between floors.
- Marine & Offshore Platforms. Drilling control and fire pump circuits on FPSO vessels and jack-up rigs where salt spray, continuous vibration, and SOLAS fire zone requirements all apply simultaneously. Tinned copper drain wire resists galvanic corrosion in marine air.
- High-Rise Commercial & Hospital Buildings. Fire alarm loops, pressurization fan controls, and voice evacuation systems requiring both fire resistance and verified signal integrity under electrical noise from HVAC variable-speed drives.
International Compliance & QA Standards
- ✅ IEC 60331-21 – Fire Resistance Test: Circuit integrity at 750°C for 90 minutes.
- ✅ IEC 60332-3-22 – Flame Propagation: Category A bunched cable vertical tray test.
- ✅ IEC 61034 – Smoke Density: Low smoke emission measuring light transmittance.
- ✅ IEC 60754-2 – Halogen Acid Gas: pH and conductivity limits exceeded for LSZH declarations.
- ✅ IEC 60228 – Conductor Classes: Copper conductor dimensional and resistance requirements.
- ✅ CE Marking – EU Low Voltage Directive 2014/35/EU.
- ✅ RoHS 3 (EU 2015/863) – Hazardous substance restriction compliance.
- ✅ ISO 9001:2015 – Manufacturing facility quality management system audited annually.
FAQ
Q: How does N-DJYP3V22 differ from FP200 or standard fire-resistant cables?
A: FP cables are typically light-duty and designed for fire alarm systems in dry premises. N-DJYP3V22 adds three elements missing from those products: individual pair shielding for instrumentation signals, a polyethylene insulated core for stable capacitance across temperature swings, and steel wire armor for mechanical protection. It is built for process automation, not just fire detection loops. If your application involves analog 4-20 mA loops or Modbus serial links near heavy rotating equipment, the shielded twisted-pair construction is the decisive factor.
Q: Can the outer sheath be supplied in LSZH (Low Smoke Zero Halogen) material?
A: Yes. The standard stock configuration uses black PVC with oil resistance. On request, we replace the outer sheath with a thermoplastic LSZH compound that meets IEC 60754-2 (acid gas), IEC 61034 (smoke density), and IEC 60684-1 (oxygen index > 32%). Lead time extends by 10 to 14 working days for LSZH orders because sheathing lines require dedicated material cleanup between runs to avoid cross-contamination. Specify LSZH explicitly at the RFQ stage.
Q: What is the minimum order quantity and typical lead time for custom pair counts?
A: Our standard stock ranges cover 2- to 24-pair configurations. MOQ is 50 meters for stock items. For non-standard pair counts (e.g., 7 pairs, 14 pairs, 30+ pairs), the MOQ rises to 500 meters per cross-section because conductor stranding, twisting bobbins, and lay plates must be reconfigured on the twisting machine. Lead time is 4 to 5 weeks from receipt of order and upfront payment. We provide an exact delivery date within 48 hours of receiving your specification.
Request a Project-Specific Quote
We prepare a formal commercial offer tailored to your bill of quantities, not a generic price list. This offer includes conductor cross-section verification against voltage drop, pair count optimization, and sheath material specification based on your installation environment.
To receive a quote within one working day, contact us with the following: total cable length per pair count, installation method (tray, conduit, direct bury), and whether LSZH outer sheath is required. Email our engineering desk directly or use the inquiry form on this page.