QXRT cable

QXRT cable is a special cable with specific design and application scenarios, and its electrical performance needs to be comprehensively analyzed based on its structural characteristics (such as conductor material, insulation material, shielding method, sheath type, etc.). The following provides a systematic analysis of the electrical performance of QXRT cables from the perspectives of core electrical parameters, the impact of structure on performance, typical application scenarios, and selection considerations:

1、 Core electrical performance parameters

2、 The influence of structure on electrical performance

1. Conductor material and cross-sectional area

• Copper conductorExcellent conductivity (resistivity 0.0172 Ω· mm ²/m), suitable for high-frequency signal transmission; But the cost is relatively high.

• Aluminum conductorLightweight and low-cost, but with a high resistivity (0.0283 Ω· mm ²/m), it is necessary to increase the cross-sectional area to reduce the resistance.

• Selection of cross-sectional areaAccording to the requirements of load current and voltage drop (such as 2.5mm ² copper conductor can carry about 28A current).

2. Insulation materials

• XLPE (cross-linked polyethylene)：

• High temperature resistance level (long-term operation at 90 ℃), high dielectric strength (≥ 20kV/mm), suitable for medium and high voltage cables.

• Low dielectric loss (tan δ ≈ 0.0002) and low signal transmission loss.

• silicone rubber：

• Wide temperature resistance range (-60 ℃ to+180 ℃), good flexibility, suitable for mobile devices.

• The dielectric constant is relatively high (≈ 3.5) and the capacitance is large, so attention should be paid to signal distortion.

• PVC (polyvinyl chloride)：

• Low cost, but poor temperature resistance (long-term operation at 70 ℃), containing halogens, and producing toxic gases during combustion.

• Suitable for low voltage, fixed installation scenarios.

3. Shielding layer design

• Copper wire braided shielding：

• Shielding density ≥ 80% (high frequency ≥ 95%), balancing flexibility and shielding effectiveness.

• Suitable for dynamic bending scenarios (such as robotic arms).

• Copper tape wrapped shielding：

• The shielding coverage rate is 99.99%, with high shielding effectiveness (≥ 80dB), but poor flexibility.

• Suitable for static installation (such as wiring inside control cabinets).

• Phase separation shielding：

• Each core wire is independently shielded to reduce interference between core wires and improve signal quality.

• Suitable for multi signal transmission (such as sensor cables).

4. Sheath material

• PUR (polyurethane)：

• Wear resistant, oil resistant, chemical resistant, suitable for industrial environments.

• Flame retardancy can be improved by adding flame retardants (such as those that comply with UL 94 V-0).

• TPE (thermoplastic elastomer)：

• Good flexibility and excellent low-temperature performance (no brittleness at -60 ℃), suitable for mobile devices.

• Poor weather resistance, long-term exposure to ultraviolet radiation should be avoided.

• LSZH (Low Smoke Zero Halogen)：

• There is no halogen release during combustion, and the smoke density is low, which meets the fire prevention requirements of public buildings.

• The temperature resistance is average (70 ℃ to 90 ℃), and the cost is relatively high.

3、 Typical application scenarios and electrical performance requirements

1. Industrial automation

• demandResistant to electromagnetic interference, oil stains, and frequent bending.

• QXRT cable configuration：

• Conductor: Tin plated copper wire (anti-oxidation).

• Insulation: Silicone rubber (temperature resistance -60 ℃ to+180 ℃).

• Shielding: Copper wire weaving (density ≥ 95%).

• Sheath: PUR (wear-resistant, oil resistant).

• performance advantage：

• Shielding efficiency ≥ 60dB (10MHz), reducing frequency converter interference.

• Bending radius ≤ 6 times the outer diameter, suitable for robot arm movement.

2. New energy power generation

• demandUV resistant, ozone resistant, and long-lasting.

• QXRT cable configuration：

• Conductor: Annealed copper (low resistance).

• Insulation: XLPE (temperature resistance of 90 ℃, high dielectric strength).

• Shielding: Copper tape wrapping (99.99% coverage).

• Sheath: LSZH (flame retardant, low smoke).

• performance advantage：

• Insulation resistance ≥ 1 × 10 Ω· km (20 ℃) to prevent leakage.

• Compliant with IEC 62893 standard (for photovoltaic cables).

3. Rail Transit

• demandLow smoke halogen-free, flame retardant, and vibration resistant.

• QXRT cable configuration：

• Conductor: Soft copper (with good flexibility).

• Insulation: EPR (ethylene propylene rubber, temperature resistance -40 ℃ to+120 ℃).

• Shielding: phase separation shielding+total shielding (copper wire braided).

• Sheath: LSZH+steel belt armor (anti rodent and ant).

• performance advantage：

• Smoke density ≤ 50 (GB/T 17651), meeting the fire prevention requirements of subway.

• Tensile strength ≥ 15MPa (steel belt armor enhances mechanical strength).

4. Medical equipment

• demandLow capacitance, low noise, biocompatibility.

• QXRT cable configuration：

• Conductor: Silver plated copper (low resistance, anti-oxidation).

• Insulation: FEP (Fluorinated Ethylene Propylene, dielectric constant 2.1).

• Shielding: Copper wire weaving+aluminum foil (double-layer shielding).

• Sheath: TPE (flexible and non-toxic).

• performance advantage：

• Capacitor ≤ 0.08 μ F/km to reduce signal distortion.

• Compliant with ISO 10993 biocompatibility standard.

4、 Selection precautions

1. Temperature matching

• Select the rated temperature level of the cable based on the highest environmental temperature (such as XLPE insulation for long-term use at 85 ℃).

• TPE or silicone rubber sheath should be selected for low-temperature environments (<-15 ℃) to avoid embrittlement.

2. chemical compatibility

• Confirm the compatibility between the sheath material and the contact medium (such as oil, acid, alkali).

• For example, PUR sheath is resistant to mineral oil, but should avoid contact with strong oxidants such as concentrated sulfuric acid.

3. Mechanical demand

• Frequent movement: Choose high flexibility cables (such as copper wire braided shielding+TPE sheath).

• Direct burial laying: choose steel belt armor+anti rodent and ant outer sheath (if supported by the model).

4. electromagnetic environment

• Strong interference scenarios (such as frequency converter output): Copper tape shielding (shielding density ≥ 95%) must be used.

• Multi signal transmission: Choose phase shielded cables to reduce crosstalk.

5. Fire prevention requirements

• Public buildings: Choose LSZH sheath+flame retardant (if compliant with GB/T 19666).

• Explosion hazardous area: Choose explosion-proof type (such as ATEX certification).

5、 Maintenance and testing

1. regular testing

• Insulation resistance testUsing a 500V megohmmeter, it is recommended to use ≥ 1M Ω/km.

• Continuity test of shielding layerEnsure that the shielding layer has no open circuits or poor contacts.

• Visual inspectionCheck if the sheath is cracked, worn, or deformed.

2. Fault handling

• If the insulation resistance decreases or the shielding layer fails, the cable needs to be replaced immediately.

• Avoid long-term exposure of cables to high temperatures or chemically corrosive environments.