N-DJYVP22 Fire-Resistant Shielded Control Cable for Critical Signal Circuits

Signal dropout during an emergency shutdown isn’t just an operational hiccup. It’s a direct path to equipment damage, safety incidents, and costly unplanned downtime. The N-DJYVP22 cable is engineered to keep data transmission intact under direct flame conditions while actively rejecting electromagnetic interference. This makes it a practical, specification-grade solution for connecting instruments, controllers, and DCS modules in projects where both fire integrity and signal clarity are non-negotiable.

Why This Cable Goes Into High-Reliability Specs

Fire Resistance Layer (The “N” Designation)

Instead of a standard construction that fails the moment it touches flame, the N variant integrates a specially compounded mica tape over the conductors and an optimized insulation system. The result is circuit integrity that matches the rigorous duration and temperature thresholds laid out in IEC 60331. What does that mean on your site? Electrical continuity stays live long enough for safe evacuation sequences, ventilation systems to run, and emergency alarms to keep signalling. Shorter shutdowns. Fewer asset write-offs.

Copper Wire Braid Shield Over Every Pair

Low-frequency data frames pollute fast when VFDs, switchgear, and high-voltage power trays run nearby. We apply a tinned copper wire braid with controlled optical coverage directly over the cores. This shield creates a uniform Faraday cage that intercepts transient electromagnetic noise and capacitive coupling before it reaches your analog 4-20 mA loops or RS-485 streams. The benefit registers immediately in the control room: rock-steady PLC readings, zero ghost tripping, and commissioning that finishes on schedule.

Galvanized Steel Tape Armour (22-Type)

Pulling cable through congested cable trenches, under access roads, or across factory floors puts lateral pressure and impact stress on the sheath. The double-strip galvanized steel armour wrapped helically under the outer sheath absorbs that punishment. No additional conduit. No sand bedding overkill. Direct lay into ungrounded troughs becomes a viable, labour-saving installation method. It also acts as a physical barrier against rodents in grain storage, wastewater plants, and food processing basements. Repair call-outs drop. Asset lifespan stretches.

Consistent Low-Voltage Transmission Characteristic

Capacitance imbalance and surge impedance mismatches are silent killers of long cable runs. The symmetric layer design and precise concentricity we maintain during extrusion hold the mutual capacitance and L/R ratios stable across the production length. For the commissioning engineer, that means fewer termination tweaks, predictable signal timing, and a validated link budget that doesn’t need a last-minute re-design. It ships pre-tested with your order’s unique batch report.

Technical Construction & Compliance Parameters

Where This Cable Fits into Real Projects

• Underground metro and rail tunnels – maintains escalator, ventilation damper, and fire pump control circuits during tunnel fires where evacuation windows are tight and smoke extraction must never lose power.
• Petrochemical tank farms and jetty pipelines – shields 4-20 mA level sensor loops from VFD-driven pump noise while the armour enables direct burial without additional sleeve, cutting trench preparation time.
• Thermal power plant cable galleries – separates critical boiler protection DCS signals from adjacent MV power cables; the steel armour eliminates the need for costly stainless-steel ladder tray dividers.
• Pharmaceutical cleanroom HVAC control – the tight braid coverage prevents false readings on humidity, differential pressure, and particle count sensors that would otherwise trigger a batch quarantine.
• Steel mill and smelter hot zones – survives radiant heat soak and mechanical vibration near continuous casting lines where ordinary screened cables embrittle within months.

International Compliance & QA Checklist

✅ Fully traceable material certificates included with each drum or reel
✅ Third-party fire resistance test report per IEC 60331-21 available upon tender submission
✅ CE marking under the Low Voltage Directive (LVD) for relevant voltage boundaries
✅ RoHS (Restriction of Hazardous Substances) compliant across all insulating and sheathing compounds
✅ ISO 9001:2015 audited manufacturing process with in-line spark testing, diameter gauging, and armour wrapping tension control
✅ Optional BS 6387 CWZ certification verified by accredited test house when specified in the purchase order

Frequently Asked Questions

What does the “N” prefix and “22” suffix actually mean in the type code?
“N” confirms a fire-resistant construction tested to maintain circuit integrity under defined flame conditions, typically using a mica tape under the insulation. “22” indicates a two-strip galvanized steel tape armour mechanically protecting the cable from compression, impact, and rodent attack. The core “DJYVP” portion identifies computer-grade screened cable with XLPE insulation and a tinned-copper wire braid shield.

We are evaluating alternatives to armoured SWA cables. Can N-DJYVP22 handle frequent flexing or drag-chain motion?
No. The steel tape armour is built for static installation—tray, duct, trench, or direct burial. It is not rated for continuous flexing or powered cable carrier use. If your layout involves moving machine heads or robot arms, we would guide you toward a shielded flexible control cable with a braid-only armour substitute. For fixed routing, this cable delivers excellent cut-through and crush resistance.

What documentation do you ship with an export order, and can we access the datasheet before placing a PO?
Every wooden reel or coil carries a standard commercial invoice, packing list, and a factory test report summarizing DC resistance, insulation resistance (IR), voltage withstand results, and dimensional checks. Third-party test certificates for fire resistance, smoke index, or flame propagation are supplied as separate documents when stated in the contract. The full engineering datasheet—covering ampacity derating curves, correction factors in air and in ground, and recommended gland sizes—is available by email within one working day. No purchase commitment needed.