China Zhenglan Cable Technology Co., Ltd Company News

In long-distance lines or high-current circuits, single-core cables are recommended to reduce intermediate joints and save costs. Furthermore, single-core cables are also suitable for low-voltage DC power supply circuits.   At voltage levels of 1kV and below, if the power supply neutral point is directly grounded and the protective conductor and neutral conductor share the same conductor in a single-phase circuit, a 2-core cable should be selected. For DC power supply circuits, a 2-core cable is also recommended. Of course, depending on specific grounding and current requirements, 3-core and 4-core cables are also available.   4-core cables (3+1 structure) for 1kV and below not only use the fourth core for protective grounding but also bear the important task of transmitting unbalanced current and short-circuit current in the power system. Their specifications need to be determined based on the actual requirements of unbalanced current and short-circuit current, but generally should not be less than 1/2 of the phase conductor's current carrying capacity. In low-voltage power distribution systems of 1kV and below, if a three-phase four-wire system is used, and the protective earth (PE) and neutral (PN) conductors share the same conductor, a 4-core cable must be selected to avoid power frequency interference problems caused by non-standard configurations.   For electrical installations with extremely high safety requirements, and for communication centers and automation equipment that require simultaneous electrical safety and interference-resistant grounding, a 5-core TN-C low-voltage power distribution system is recommended. This allows the protective earth (PE) and neutral (PN) conductors to operate independently, with their core cross-sectional areas typically being 3 large and 2 small, 4 large and 1 small, or 5 large, ensuring independent PE and PN conductors and providing reliable grounding and interference immunity.

Dear Customer Thanks for visiting our website. Due to Labor Day is coming, kindly note we will be on holiday from Friday(May 1st) to next Tuesday(May 5th). Work resume from Wednesday(May 6th). If you have any needs, please feel free to send us inquiry via email. We will handle them once we come back. Hope you will have a happy holiday.  Zhenglan Cable Technology Co., LtdApril 30th, 2026

The cross-sectional area of ​​a cable refers to the cross-section of its copper or aluminum core. The cross-sectional area of ​​a cable in practical applications involves three different concepts that need to be distinguished: 1. Nominal Cross-sectional Area: A numerical value used to determine a specific conductor size. It is a code for the product specification model and does not require direct measurement of the actual cross-section. It is mainly used for document management and production guidance. 2. Design Cross-sectional Area: A value that must not be lower than the design value in low-voltage power distribution systems. The focus of the assessment is whether the conductor resistance value meets the standard, not the geometric dimensions. 3. Actual Cross-sectional Area: The geometric cross-sectional area of ​​the conductor. The manufacturer must ensure that the DC resistance of the conductor meets the standard requirements at this nominal cross-section. The actual cross-section may be adjusted due to differences in material conductivity. Calculation and Selection Basis for Cable Cross-sectional Area Calculation Method: The formula for the cross-sectional area of ​​a single-strand conductor is S=πr²; for multi-strand stranded conductors, it is the cross-sectional area of ​​a single strand multiplied by the number of strands. Selection Criteria: When selecting a cable type, factors such as long-term allowable current carrying capacity, economic current density, grid voltage drop, and short-circuit current magnitude must be comprehensively considered. Environmental Impact: High temperature, low temperature, humidity, and laying method (such as direct burial or conduit) all affect cable performance. Appropriate materials and specifications must be selected in accordance with local electrical codes.

With the increasing global demand for clean energy, the new energy industry is developing rapidly. New energy cables, as a key component of new energy systems, are becoming increasingly diverse and varied in type and specifications. (1) Solar CablesAlso called photovoltaic cables, they are used in solar photovoltaic power generation systems to connect photovoltaic modules, combiner boxes, inverters, and other equipment. • Features: UV resistant, high and low temperature resistant, ozone resistant, chemical corrosion resistant, etc. • Conductor cross-sectional area: Commonly 1.5mm², 2.5mm², 4mm², 6mm², etc. • Number of cores: Generally 1 core or 2 cores. • Voltage rating: Usually DC 1000V or DC 1500V. (2) Energy Storage CablesEnergy storage cables are cables specifically designed for energy storage systems, possessing a series of unique characteristics and functions. Energy storage cables typically require good electrical performance, including low resistance to reduce energy loss and high insulation performance to ensure safe and reliable power transmission. They must be able to withstand large current and voltage changes and adapt to the frequent charge and discharge cycles of energy storage systems. • They must possess good high-temperature resistance, aging resistance, low smoke, and halogen-free properties. • Conductor cross-sectional area: Wide range, commonly ranging from 4mm² to 240mm² • Number of cores: Generally 1 core. • Voltage rating: Commonly DC 1000V, DC 1500V, etc. Common models: EV, EVRP series, and the EU standard UL series. (3) Charging pile cablesCharging pile cables are important components connecting electric vehicles and charging piles, mainly used for transmitting electrical energy to realize the charging function of electric vehicles. • High current carrying capacity, good flexibility, high temperature resistance, wear resistance, and waterproof properties. Voltage rating: Charging pile cables are divided into AC and DC. Common household cables are AC450/750V, while large charging stations are generally DC 1000V, DC 1500V, etc. • Number of cores: AC cables are generally 3 cores. DC cables typically have 5 or more cores due to the control line component. • Common models: AC cables are generally YJV, YJVR, or EV series; DC cables are EVDC series or 62893IEC126 standard series. (4) Wind Power CablesWind power cables, also known as wind turbine cables, need to be flexible and capable of frequent twisting to adapt to the automatic yaw of wind turbines; they also need to have strong vertical tensile strength to adapt to the vertical suspension installation of wind turbines. Conductor cross-sectional area: Wide range, commonly used from 4mm² to 240mm² • Voltage rating: 450/750V, 0.6/1KV, 1.8/3KV • Number of cores: AC cables are generally 1-5 cores; signal output sections have 6-36 cores.

Fire-resistant electrical wires are crucial. In case of fire, critical systems like alarms, smoke extraction, and emergency lighting all depend on them – they are truly a "lifeline." But how do you choose the right fire-resistant wires? Actually, just remember these four types, and you too can become an expert! What types of fire-resistant wires are there? According to the "General Principles for Flame-Retardant and Fire-Resistant Wires and Cables," fire-resistant wires are mainly divided into the following four types: Flame-retardant cables (ZR): If these cables encounter fire, they won't burn immediately, but will burn slowly. Once the fire is extinguished, they will stop burning themselves, preventing the fire from spreading further. They are suitable for general fire safety equipment, such as manual alarm buttons. Fire-resistant cables (NH): These can withstand high temperatures of 750℃ and can continuously supply power for 90 minutes. Their insulation layer uses mica tape, which is particularly heat-resistant. Equipment that is particularly important during a fire, such as smoke exhaust fans, fire pumps, and emergency lighting, requires this type of cable. Mineral insulated cables (BTTZ): These have a copper core and magnesium oxide insulation. Their advantage is that they can withstand high temperatures of 950℃ and are also waterproof and explosion-proof. They are essential for ensuring power supply safety in places with extremely high safety requirements, such as super high-rise buildings, tunnels, and nuclear power plants. Halogen-free low-smoke cables (WD): When these cables burn, they produce very little smoke and no toxic gases. According to the standard, the light transmittance can reach over 60%. Therefore, they are safer in densely populated areas such as subways, hospitals, and schools, reducing the harm caused by smoke and toxic gases during a fire. 5 tips for choosing fire-resistant wires: Consider the building type: For super high-rise buildings or underground projects, mineral insulated cables (BTTZ) are a must, as only they can guarantee stable power supply in such extremely complex and dangerous environments. For ordinary commercial buildings, it's best to use a combination of fire-resistant (NH) and halogen-free low-smoke (WD) cables. This ensures both safety and meets practical needs. Select based on system importance: For critical equipment like fire pumps and smoke exhaust fans, which play a crucial role in fire fighting, mineral insulated cables must be used, as their stable operation is vital to the success of the entire fire protection system. For secondary load equipment like emergency lighting, fire-resistant (NH) cables are sufficient and more cost-effective. Choose based on the installation environment: If installed in damp places, such as basements or swimming pools, cross-linked polyethylene insulated (YJV) cables should be used, and the waterproof rating must be IP67 or higher to prevent water from affecting the cable's normal operation. In corrosive environments, such as near chemical plants, armored cables like NH-YJV22 should be used, as their outer sheath can resist corrosive substances such as acids and alkalis. Consider cost: If you want to save money, use flame-retardant cables (ZR) and supplement them with fire-resistant cables (NH) in critical areas. This ensures basic safety while controlling costs. If you prioritize extremely high reliability and don't mind spending more, use mineral insulated cables (BTTZ) throughout the entire system, although this will increase costs by approximately 30% to 50%. Follow regulations: If fire protection power lines are laid openly, they must be routed through metal conduits or enclosed metal trunking and coated with fire-retardant paint to further enhance fire safety. How to check the quality after selection: Check certificates: When purchasing cables, the supplier should provide a third-party test report containing key data such as fire resistance time and smoke density. This report confirms whether the cable meets the standards. Test performance: Samples can be sent to a professional institution for testing.  The insulation resistance should be tested, and it must be above 20MΩ.  Fire resistance should also be thoroughly tested to determine the actual quality of the cable. Inspection of markings:  Legitimate cables will have clear markings such as "NH" and "WD" printed on the outer sheath, indicating the cable type. These markings should be clear and not easily rubbed off. If the markings are unclear or easily erased, the cable is likely defective. Future trends in fire-resistant cables: Flexible mineral-insulated cables: These cables may gradually replace traditional BTTZ cables in the future because they have a smaller bending radius, making installation easier and increasing construction efficiency by 50%. This will save considerable time and labor costs. Intelligent monitoring cables: These cables are equipped with temperature sensors. If the line temperature becomes too high, an alarm will be triggered immediately, allowing for early detection of potential hazards and preventing fires. This is particularly helpful for fire safety. Environmentally friendly materials: According to industry forecasts for 2025, the proportion of halogen-free, low-smoke cables will increase to 80%.  More and more places will use these more environmentally friendly and safer cables in the future, reducing the harm to the environment and people during fires.

Polyethylene (PE)Characteristics: Polyethylene is divided into low-density (LDPE), medium-density (MDPE), and high-density (HDPE). It has excellent low-temperature resistance (remaining flexible at -60°C), excellent chemical resistance, low water absorption, and good electrical insulation properties. HDPE also has high strength and excellent weather resistance.Advantages:Suitable for outdoor, buried, submarine, and high-altitude environments, such as communication cables, fiber optic cables, and offshore wind power cables.Environmentally friendly and recyclable, with minimal environmental impact.MDPE and HDPE, after carbon black stabilization treatment, have outstanding UV resistance and are suitable for long-term exposure to sunlight.Limitations: Untreated PE is flammable and has poor flame retardancy, so it is not recommended for indoor locations with high fire safety requirements.Low Smoke Zero Halogen (LSZH/LSOH)Characteristics: LSZH (Low Smoke Zero Halogen) materials are usually based on polyolefins, with aluminum hydroxide or magnesium hydroxide added as flame retardants.  They produce extremely low smoke concentrations during combustion and do not release halogen-containing toxic gases.Advantages:High safety: Designed for densely populated or enclosed spaces, such as subways, tunnels, data centers, hospitals, high-rise buildings, and public transportation systems.Minimal corrosive gas emissions during combustion, reducing secondary damage to equipment and personnel.Complies with modern building and industrial safety standards, and is an environmentally friendly upgrade alternative to PVC.Limitations: Higher production costs than PVC and PE, and more complex processing technology, resulting in higher cable prices.Polyvinyl Chloride (PVC)Characteristics: PVC is one of the most widely used sheath materials, with low cost, good flexibility, acid and alkali resistance, and a certain degree of flame retardancy.Advantages:Economical and practical: High cost-effectiveness, easy to process, suitable for indoor wiring, low-voltage power cables, and general industrial cables.Good mechanical protection and insulation performance, suitable for fixed installation in general environments. Limitations:It softens easily at high temperatures (the typical long-term operating temperature does not exceed 80°C), and may become brittle at low temperatures.It contains halogens, and when burned, it produces a large amount of dense smoke and toxic gases such as hydrogen chloride, which does not meet the high safety standards of modern buildings.It is not suitable for places with strict requirements for environmental protection and smoke toxicity.