N-DJYVP2-22 Cable: Armoured Shielded Instrumentation Cable for Noise-Immune Signal Integrity

In a live process plant, a single corrupted instrument signal can trigger a false shutdown. The cost isn’t the cable — it’s the unplanned downtime, the spoiled batch, the HAZOP review. N-DJYVP2-22 cable eliminates that risk in installations where physical damage and electromagnetic interference converge. It puts a copper tape screen and a galvanised steel tape armour between your signal conductors and the plant floor. The result is a cable that holds its transmission parameters under conditions that would fracture ordinary PVC-sheathed control wiring.

Shielding That Rejects EMI at the Source

• Copper tape screen, 100% wrap coverage. The copper tape layer provides a continuous, low-impedance path to ground for electrostatic and electromagnetic noise. This means the signal arriving at your DCS or PLC I/O card is the same signal that left the transmitter. No filtering artefacts, no retransmits, no logic timeouts complicating a commissioning sequence.
• Drain wire continuity. Each screened pair includes a tinned copper drain wire. It makes field termination predictable and keeps the shield impedance linear across the full cable run — something a patchy copper braid can’t promise.

Steel Tape Armour: Mechanical Survival Without Conduit

• Galvanised steel tape armour (0.2–0.5 mm). The armour absorbs lateral crush loads, rodent attack, and accidental impact. You can route this cable direct to tray, direct to ladder rack, or even directly buried in clean soil — no rigid steel conduit needed. That alone can remove USD 12–35 per metre from an installation budget on a medium-sized project.
• Bend radius maintained at 12 × overall diameter. The cable remains pliable enough for glanding into standard SWA glands. No custom hardware required.

Fire-Resistant Circuit Integrity (N-Type)

• Mica glass tape on conductors (fire barrier). When the PVC sheath and PE insulation are consumed, the mica layer keeps the copper conductors electrically separate. The circuit remains operational at 750 °C for a minimum of 90 minutes, tested per IEC 60331-21. For a fire alarm, emergency shutdown valve, or pressurisation fan, those 90 minutes are the difference between controlled isolation and a total plant event.

Polyethylene Insulation: Dielectric Stability Over Decades

• Solid polyethylene insulation on each conductor. PE has a dielectric constant of 2.3, stable across the cable’s full -40 °C to +70 °C operating window. This matters for any bus system where capacitance mismatch distorts square waves. With N-DJYVP2-22’s low and balanced mutual capacitance (typically 85 nF/km at 1 kHz), it supports high-speed RS-485 and CAN bus segments without an extra repeater.

UV-Stabilised PVC Outer Sheath

• Black PVC compound with carbon black loading. Sheath life exceeds 20 years in sunlight-exposed cable trays, rated for UV exposure. No secondary wrapping needed. The PVC also passes the IEC 60332-1-2 vertical flame propagation test, so the cable does not become a vertical fire path across tray levels.

Technical Specifications & Dimensions

Industry Applications & Scenario Validation

• Oil & gas onshore terminals. Buried in soil or laid in open tray with high stray currents — the copper screen prevents 50 Hz induced voltages from corrupting 4–20 mA loop signals.
• Tunnelling and mining conveyor control. Armour absorbs impact from falling aggregate; PE insulation maintains signal timing for emergency stop loops over kilometres.
• Chemical batch processing. PVC sheath resists alkalis and oils in splash zones. No delamination between sheath and armour after hot-water washdown cycles.
• Wastewater lift stations. High humidity, continuous condensation — but the polyethylene insulation does not absorb moisture, keeping insulation resistance above 5000 MΩ·km after years of immersion.
• Building management systems (fire safety circuits). N-type fire resistance ensures fire telephone, alarm, and damper control circuits remain alive during evacuation. Connects directly to terminal boxes without intermediate junction enclosures.

International Compliance & QA Standards

• ✅ IEC 60332-1-2 — Flame retardance, single cable vertical test
• ✅ IEC 60331-21 — Circuit integrity under fire at 750 °C (fire-resistant N variant)
• ✅ IEC 60754-1/2 — Halogen gas emission and acidity (testing available on request)
• ✅ IEC 61034-2 — Smoke density (testing available for LSZH sheath options)
• ✅ RoHS (EU 2011/65/EU) — Restricted substances in electrical equipment
• ✅ ISO 9001:2015 — Manufacturing quality management system
• ✅ Material traceability — Copper source certificates and steel tape mill reports provided with every batch

FAQ

How should the copper tape screen and steel armour be terminated for maximum EMI protection?
Connect the copper tape screen drain wire at one end only for low-frequency (4–20 mA) loops to avoid earth loops. At frequencies above 100 kHz, ground both ends to shorten the return path. The steel armour must be earthed at the supply end for safety; gland the armour into a metallic gland plate and bond it to the local earth bar. Never leave the armour floating — it becomes a coupling path for impulse noise.

Can N-DJYVP2-22 be used for direct burial without additional protection?
Yes, for direct burial in normal soil conditions. The steel tape armour provides mechanical protection against impact and crushing from backfill. For rocky soil, lay a 100 mm sand bed beneath and cover with warning tape. The PVC outer sheath resists soil acids, but always verify soil corrosivity. For aggressive soils (pH < 4 or resistivity < 20 Ω·m), request a PE outer sheath option.

What is the maximum cable length for RS-485 communication without a repeater?
It depends on baud rate and termination. At 100 kbps, typical reach is 1200 m with properly terminated 120 Ω characteristic impedance. N-DJYVP2-22’s low capacitance (≤85 nF/km) and uniform insulation wall thickness keep signal rise time within RS-485 transceiver limits. Above 500 kbps, plan for 300 m runs and measure eye pattern during site acceptance testing.

Talk to an Engineer Before You Specify

Every cable assembly starts with an isometric drawing that demands a specific pair count, screen isolation, and fire rating. Send us your instrument index or cable schedule and we return a technical compliance statement plus a fixed lead time within 24 hours. Write to our engineering desk at [email/contact form placeholder] or request the full type-test certification package for your project documentation.