ZA-NH-DJYPV22 Cable | Fire-Resistant Shielded Instrumentation for Critical Circuits

When instrument cables fail during a fire, the shutdown costs are calculated in seconds. The real loss, however, extends beyond equipment. Electrical designers face a specific engineering constraint: maintaining signal integrity under direct flame to keep emergency systems operational long enough for a controlled stop. This is not a standard performance metric. It is a survival requirement. The ZA-NH-DJYPV22 addresses this through an uncompromised A-class flame barrier and dual-layer shielding architecture. You get a cable that sustains circuit integrity at 950°C while rejecting the electromagnetic interference that corrupts safety loop data. The commercial result is direct: one cable that replaces layered mitigation strategies, reducing both tray weight and procurement line items.

Low Smoke, Zero Halogen, Maximum Uptime
The compound extruded here eliminates acidic gas release entirely.
Standard PVC jackets produce hydrogen chloride when burned. HCI destroys server rooms. It corrodes exposed circuit boards within hours. The NH jacket formulation ensures emissions fall below 0.5% HCI equivalent. This protects adjacent capital equipment and removes the corrosive particulate risk that typically extends post-fire recovery by weeks.

• A-Class Flame Retardancy (ZA) : Carbonization layer integrity under 950°C ± 40°C flame exposure. -> Maintains loop power to emergency shutdown valves and alarm sounders, granting operators critical minutes (typically 90-180 min) to isolate fuel sources. No data blackout during evacuation.
• Dual-Layer Electrostatic Shielding (P2- Copper Tape + Tinned Copper Braid) : Group shielding plus overall collective shielding in one construction. -> Attenuation exceeds 95dB across 0.1–100MHz. This neutralizes the crosstalk between analog signal pairs and the high-frequency noise radiated by nearby VFD motor cables. Your 4-20mA loops remain stable.
• Steel Tape Armour (22 Type) : Heavy galvanized steel interlocking over the inner sheath. -> Direct burial viability without additional conduit. Mechanical crush rating addresses crowded cable trenches in heavy industrial brownfield projects. It also acts as a primary earth continuity path.
• Polyethylene Insulated (PE) : Superior dielectric constant compared to PVC-insulated variants. -> Reduces mutual capacitance per kilometer. Reduced signal deformation over long transmission distances means you can relocate marshalling cabinets further from the junction box without signal boosters.

Technical Specifications & Dimensions
The construction identifies as Copper conductor / PE insulation / Individual pair screen / Collective overall screen / LSZH inner sheath / Galvanized steel tape armour / LSZH outer sheath.

Industry Applications & Scenario Validation
– Oil Refinery Emergency Shutdown Systems (ESD) : Links the BPCS to the final actuation valve. The ZA-NH rating ensures the valve moves to the fail-safe position even if the cable tray is engulfed. The screen blocks static interference from flowing product.
– Offshore Platform Fire & Gas Detection : Exposed on open grate trays in salt-laden winds. The steel armour resists impact from dropped objects, while the LSZH jacket avoids toxicity in the accommodation block’s return air plenum.
– Nuclear Auxiliary Buildings : Qualified for monitoring circuits outside the primary containment. The dual-screen filters gamma radiation-induced electrical noise that spooks unprotected analog inputs.
– Metro Rail Tunnel Ventilation : Installed in confined escape tunnels. Mandatory low-smoke characteristic preserves visibility for evacuees. The cable must signal dampers to open under prolonged heat exposure—this is where the 3-hour fire integrity value applies directly.

International Compliance & QA Standards
– ✅ A-Class Flame Test (IEC 60332-3-22) : Vertical tray ignition with burner energy 73.5 MJ. Char length does not exceed 2.5m.
– ✅ Fire Resistance Test (IEC 60331-21) : Voltage withstand at 950°C for the specified duration without fuse rupture.
– ✅ Smoke and Halogen Test (IEC 61034 / IEC 60754) : Confirmed non-corrosivity and low optical density during combustion.
– ✅ RoHS 3 (EU 2015/863) : Lead-free jacket and insulation pigments available for EU-bound projects.
– ✅ ISO 9001:2015 Manufacturing : Statistical Process Control (SPC) applied on insulation concentricity to guarantee consistent spark test results.

FAQ
How do you verify the circuit integrity during a fire without witnessing the factory test?
We provide the full Type Test report video and oscillograph data upon Request for Quotation. The standard IEC 60331-21 test monographs the fuse current. A flat line on the zoomed trace proves the single-second interruption threshold was never triggered during the 180-minute fire attack. This report ties back to the serialized cable drum via the heat-lot and extrusion date code.

We need to run this cable parallel to medium-voltage feeders for a run of 800 meters. Will the combination screen block the 50Hz inductive coupling?
The 22-type steel armour handles the 50Hz magnetic field component via ferromagnetic shielding. The copper tape handles the capacitive noise from the HV switching transients. We specify this combined approach precisely for shared HV/LV trenches. Specify “Electrical Segregation Upgrade” during inquiry, and we will confirm the transfer impedance test data.

What is the realistic lead time for a 300mm² custom pair configuration with pre-connectorized ends?
Standard ZA-NH-DJYPV22 in 1.5mm² pairs ships from buffer stock within 10 working days. For non-standard pair counts (above 37 pairs) or factory-attached Harting connectors, allow 20–22 days. The bottleneck is the LSZH curing cycle, not the taping. We accelerate this by running a continuous vulcanization line dedicated to LSZH—we do not batch-cure in autoclaves.

Secure a Fire-Safe Signal Path
Procurement cycles stall on technical exceptions. If fire-resistant cable test reports don’t match the project spec, rejection is guaranteed. We issue the production sequence schedule alongside the compliance matrix before you issue the PO. Get the test certificate package and a competitive delivery schedule for your next shutdown or greenfield project. Ask for the ZA-NH-DJYPV22 project quotation now.