Rated Voltage 450/750 V and Below XLPE Insulated Polyolefin Sheathed Low-Smoke Zero-Halogen Flame Retardant (Fire-Resistant) Control Cable

Executive Standards
The production and inspection of this cable series are mainly based on the following standards:
- GB/T 9330-2020: Plastic insulated control cables (core construction standard).
- Q/320481SS008-2023: Enterprise-specific standard (applicable to extended specifications and enhanced performance).
- GB/T 19666-2019: General rules for flame retardant and fire-resistant wires and cables or optical cables (combustion characteristic requirements).
- GB/T 17651 (IEC 61034): Measurement of smoke density.
- GB/T 17650 (IEC 60754): Test for halogen-free performance.

Model Code Definitions
- WDZ: Halogen-free (W), low-smoke (D), flame retardant (Z) characteristic code.
- ZA / ZB / ZC: Represents flame retardant class A, B, C.
- N: Fire-resistant property code (maintains circuit continuity under fire).
- K: Control cable series code.
- YJ: Cross-linked polyethylene (XLPE) insulation.
- Y: Polyolefin sheath (low-smoke zero-halogen flame retardant material).
- P / P2 / P3 / P4: Shielding structure (e.g., P-copper wire braid; P2-copper tape wrap; P3-aluminum/plastic composite tape wrap).
- 23 / 33: Armoring structure (23-steel tape armor; 33-fine steel wire armor, with polyolefin sheath).
- R: Flexible conductor construction.

Product Specification Range
The conductor uses high-quality annealed copper wire, with specification designs accurately covering various precision signal and power control requirements:
1. National standard specifications:
   - (2–61) cores × (0.75–2.5) mm²
   - (2–19) cores × (4, 6) mm²
   - (2–7) cores × 10 mm²
2. Enterprise extended specifications (including fine diameter and large core count power cores):
   - (2–61) cores × 0.5 mm²
   - (20–37) cores × (4, 6) mm²
   - (2–10) cores × 10 mm² (for certain specific shielded types)

Core Technical Parameters
1. Rated voltage (U₀/U): 450/750 V.
2. Temperature characteristics:
   - Maximum continuous permissible conductor operating temperature: 90°C.
   - Maximum conductor temperature during short circuit (max. 5 s): 250°C.
3. Electrical performance: The finished cable passes the power-frequency voltage withstand test, with insulation resistance constant (at 20°C) typically meeting high-standard requirements.
4. Environmental characteristics (LSZH indicators):
   - Halogen-free performance: pH value of gas released during combustion ≥ 4.3; conductivity ≤ 10 μS/mm.
   - Low-smoke performance: Minimum light transmittance for smoke density ≥ 60%.
5. Bending radius:
   - Non-armored and flexible construction cables: not less than 6 times the cable outer diameter.
   - Armored or shielded cables: not less than 12 times the cable outer diameter.

Product Structural Characteristics
- High-efficiency insulation layer: XLPE insulation is produced using a chemical or physical cross-linking process, transforming the molecular structure into a three-dimensional network. This greatly improves the material's mechanical strength, thermal aging resistance, and dielectric strength.
- Multiple anti-interference designs: The P series shielding structure uses a high-coverage metallic shield to effectively block external electromagnetic fields and interference between internal circuits, ensuring accurate transmission of weak control signals.
- Fire-resistant safety barrier (N type): The fire-resistant type is wrapped with high-performance mica tape over the conductor. Mica can withstand high temperatures above 800°C, maintaining circuit integrity even if the insulation is burned away.
- Environmentally friendly sheath system: The outer sheath is made of low-smoke zero-halogen flame retardant polyolefin, which does not contain heavy metals such as lead and cadmium or halogens. During combustion, it releases almost no halogen acid gases, with extremely low acidity.

Applicable Scenarios
- Densely populated and high-safety locations: Power monitoring systems in subway stations, tunnels, high-rise buildings, large shopping malls, and airport terminals.
- Fire interlock systems: Specifically used for critical control circuits that must remain operational during a fire, such as fire alarms, emergency lighting, and smoke exhaust fans.
- Precision industrial facilities: Power distribution outside the containment of nuclear power plants, electronic cleanrooms, and petrochemical secondary circuits, where strict restrictions on smoke corrosivity apply.

Selection and Maintenance Recommendations
1. Flame retardant class matching: For locations with extremely high fire protection requirements (such as super high-rise buildings or nuclear power supporting facilities), it is recommended to select types meeting ZA class bunched flame retardant performance.
2. Anti-interference selection: When routing near variable frequency drives or in strong electromagnetic environments, cables with shielding codes (such as P, P2) must be selected.
3. Installation temperature control: The ambient temperature during installation should not be lower than 0°C. In extremely cold conditions, the cable must be preheated to prevent damage to the sheath and internal mica tape due to cold brittleness.
4. Accessory consistency: During installation, the matching cable joints, terminations, and sealing materials should also meet low-smoke zero-halogen requirements to ensure the integrity of the entire protection system.