China Zhenglan Cable Technology Co., Ltd Company News

We are going to attend the FIEE exhibision (International Trade Show of the Electrical, Electronic, Power, Automation and Connectivity Industry) to be held on September 9th~12th at São Paulo Expo Exhibition & Convention Center, and our booth number is H4. A39.   If you are going there, welcome your coming to our booth. Look forward to meeting you.   Zhenglan Cable Technology Co., Ltd  

The International Electrotechnical Commission (IEC), the world's most authoritative electrical standards organization, specifies that safety grounding conductors must use alternating green and yellow conductors. This special color scheme requires alternating stripes of the two colors every 25 mm, creating a unique visual identifier. The choice of the yellow-green combination was based on rigorous human factors research. The two colors provide a sharp contrast in most lighting conditions, making them easily identifiable even for those with color blindness and difficult to confuse with other functional conductors.   In electrical equipment, the grounding conductor fulfills the crucial function of conducting fault current to the earth. When insulation failure causes the equipment casing to become live, a good grounding system can trigger protective devices to disconnect power within milliseconds, preventing electric shock accidents. Standardized colors enable operators to instantly identify grounding conductors, significantly reducing the risk of misoperation during emergency repairs or routine maintenance. Studies have shown that standardized color coding can increase electrical maintenance efficiency by 40% and reduce accident rates by over 60%.   While the IEC standard has been adopted by most countries, the United States maintains its unique grounding conductor specifications. According to the US National Electrical Code (NEC), grounding wires can be either bare copper wire or solid green insulated conductors. This difference stems from the history of electrical engineering. Early US electrical systems used green as a grounding color, a color that remains in place today to maintain system continuity. In contrast, the UK and EU countries strictly enforce the yellow-green stripe standard, with regulations such as BS 7671 clearly stipulating legal liability for non-compliance.   Special circumstances often require workarounds. High-voltage substations may use orange grounding wires, while offshore platforms may use blue. These exceptions require special approval from regulators, prominent warning signs on the equipment, and specialized training for personnel.

  Cable shielding density is a quantitative indicator of the shielding ability of a cable shield against electromagnetic signals. It is usually expressed as a percentage, reflecting the degree to which the shield can block or attenuate electromagnetic interference. For example, in the case of a braided shield, the shielding density depends on factors such as the thickness of the braided wires and the tightness of the weave. A higher braid density means smaller gaps between the braided wires, and thus a stronger ability to block electromagnetic interference. For example, a shielding density of 90% means that the cable shield can theoretically block 90% of external electromagnetic interference signals, allowing only 10% of interference signals to pass through the shield and affect signal transmission within the cable.   Common cable shielding densities vary. The following are some of the more common ones: • 70%: Provides a certain degree of protection against external electromagnetic interference and is suitable for general electrical equipment connections with relatively low electromagnetic shielding requirements. • 80%: Provides good electromagnetic interference suppression and is commonly used for internal wiring of general electronic equipment and office equipment. • 90%: Provides excellent shielding effectiveness and is suitable for applications with certain electromagnetic environment requirements, such as industrial automation control systems. • 95%: Offers high shielding performance and is commonly used in cables sensitive to electromagnetic interference, such as communications and data transmission. • 98%: High shielding density, suitable for specialized applications with stringent electromagnetic shielding requirements, such as medical equipment and aerospace. • 99% and above: Provides extremely excellent shielding effectiveness and is generally used in military, high-end scientific research, and other applications with extremely high electromagnetic compatibility requirements.   The selection of cable shield braid density requires comprehensive consideration of multiple factors, including the application scenario, equipment requirements, and cost.   Chinese standards have different requirements for cable shielding density: • For single-core shielded cables with a nominal cross-section of 0.12 mm² or less, the shield braid density should be no less than 60%. • For other shielded cables, the shielding density should be no less than 80%. • For computer cables: The individual shielding density must reach 85%, and the total shielding density must reach 95%. • For control cables: When using round copper wire braided shielding, the braid density should be no less than 80%.

The main reasons for using fumigated wooden trays for cable export are: 1. Compliance with international quarantine requirements. • Regulatory Compliance: Most countries/regions around the world have strict quarantine regulations to prevent wooden packaging from carrying harmful organisms (pests, insect eggs, pathogens, etc.) that could cause biological invasions or spread plant pests and diseases. • Core Measures: Fumigation kills harmful organisms in the trays, ensuring that the goods pass quarantine inspection in the importing country and avoiding the risk of return or destruction. 2. Protecting Cable Products. • Structural Advantages: The trays are sturdy, providing stable support for the cables and resisting mechanical damage such as collisions and crushing during transportation and loading and unloading. • Environmental Adaptability: Wood's natural moisture-proof and cushioning properties reduce the effects of humidity, vibration, and other environmental factors on the cable insulation and outer sheath. 3. Ease of Transportation and Loading and Unloading. • Standardized Design: Fumigated wooden trays have uniform specifications (such as diameter and load-bearing capacity) to accommodate cable winding and securing, improving storage and stacking efficiency. • Mechanized Operation: The standardized design facilitates forklift and crane operation, reducing manual handling losses and optimizing logistics space utilization. IV. Environmental Sustainability • Material Characteristics: Wood is a renewable resource and can be recycled after use, aligning with the global trend towards green packaging. • Comparative Advantages: Lower carbon footprint compared to single-use plastic/metal packaging, reducing waste disposal costs. How to Determine the Compliance of Fumigated Wooden Trays 1. Check the IPPC Mark ✅ Core Marking Elements: • IPPC (International Plant Protection Convention) logo • Country code (e.g., CN for China) • Treatment agency code (e.g., HT for a fumigation agency) • Treatment method code (e.g., MB for methyl bromide fumigation) • The mark is typically printed or branded in a conspicuous location on the wooden tray (e.g., edge or side). II. Verify the Fumigation Certificate ✅ Key Certificate Information: ・ Treatment date, location, number of pallets, and specifications; ・ Fumigant type (e.g., methyl bromide), concentration, and treatment duration; ・ Implementation standards (e.g., ISPM 15 International Wood Packaging Standard); ・ Issuing agency seal and validity period, which must be issued by an officially recognized quarantine agency. III. Preliminary Appearance Inspection (Supplementary Reference) ⚠️ Non-absolute basis for judgment: ・ The wood may appear slightly yellow (a sign of chemical penetration); ・ Occasional light brown chemical stains or slight cracks may be seen on the surface (a natural phenomenon during the drying process); • Appearance alone is not acceptable for judgment; the inspection must be based on both the label and the certificate. IV. Professional Testing and Verification ✅ Scientific Testing Methods: 1. Chemical Analysis: Check the wooden pallets for residual fumigants (such as methyl bromide). Residual levels must be below international safety standards. 2. Biological Testing: Microscopic observation or culture methods confirm the absence of live insects, eggs, and microbial residues. 3. Application Scenarios: For high-risk cargo or trade disputes, commission a third-party testing agency to issue a report. Key Points Summary Necessity of Use: Quarantine compliance is mandatory, and wooden pallets offer advantages in terms of protection, logistics, and environmental protection. Compliance Assessment: Prioritize verification of the IPPC mark and official certificate. Appearance is a secondary reference, and professional testing is the final decision.

Part 1: The role and use of shielding cable Shielding cable is a transmission line that uses a metal mesh braided layer to wrap the signal line. The braided layer is generally red copper or tinned copper. Shielding cable is a kind of wire with a metal braided shell specially used to reduce the influence of external electromagnetic fields on power or communication lines. This shielding cable also has the function of preventing the line from radiating electromagnetic energy outward. The shielding layer needs to be grounded, and external interference signals can be introduced into the earth by this layer. The shielding layer of the shielded cable is mainly made of non-magnetic materials such as copper and aluminum, and the thickness is very thin, which is much smaller than the skin depth of the metal material at the frequency of use (the so-called skin effect refers to the distribution of current in the conductor cross section tending to the surface of the conductor as the frequency increases. The higher the frequency, the smaller the skin depth; that is, the higher the frequency, the weaker the penetration ability of electromagnetic waves. The effect of the shielding layer is not mainly due to the reflection and absorption of the electric field and magnetic field by the metal body itself, but due to the grounding of the shielding layer. Different grounding forms will directly affect the shielding effect.   Part 2:  Structure The wrapped conductor is called a shielding layer, which is generally a conductive cloth, a braided copper mesh, or copper (aluminum) platinum. Ordinary: insulation layer + shielding layer + conductor; advanced: insulation layer + shielding layer + signal conductor + shielding layer grounding conductor The shielding layer generally needs to be grounded. The function of the shielding wire is to isolate the electromagnetic field noise source from the sensitive equipment and cut off the propagation path of the noise source. Shielding is divided into active shielding and passive shielding. The purpose of active shielding is to prevent the noise source from radiating outward, which is a shielding of the noise source; the purpose of passive shielding is to prevent sensitive equipment from being interfered with by the noise source, which is a shielding of sensitive equipment. The shielding layer of the shielded wire is not allowed to be grounded at multiple points, because different grounding points are always different, and there is a potential difference at each point. If multiple points are grounded, current will be formed in the shielding layer, which will not only fail to play a shielding role, but will also introduce interference. Especially in occasions where frequency converters are used frequently, the interference contains various high-order harmonic components, which will cause greater impact and should be paid special attention to.

The main reasons for the large price difference of wires and cables of the same model and specification include the following aspects: ‌1. Raw material cost difference ‌: National standard cables usually use oxygen-free copper as raw material, while non-standard cables may use scrap copper. Although scrap copper and oxygen-free copper have the same weight, the price difference is 10%. Since copper accounts for most of the cost of cable raw materials, this raw material difference is particularly evident in price ‌ 2. Auxiliary material quality difference ‌: Non-standard cables may cheat on auxiliary materials and use materials of slightly lower quality. Although the cost of auxiliary materials only accounts for about 20% of the cost of cables, if poor quality auxiliary materials are used, a 5% price difference can be generated with national standard cables .   3. Wire length problem ‌: Non-standard cables may have a short meter phenomenon, that is, the actual length is less than the nominal length. For example, a 100-meter line may only have 99 meters. Although the number of meters reduced each time is not much, the cumulative cost can be significantly reduced ‌ 4. Structural differences‌: Some non-standard cables make a fuss about the structure, using national standard materials at both ends and non-standard materials in the middle. Although this practice reduces costs, it may affect the quality and performance of the cable. Since samples are usually not cut from the middle during testing, this practice has a certain degree of concealment‌   ‌How to identify high-quality wires and cables‌: ‌Check the composition of copper‌: High-quality wires and cables should use oxygen-free copper, not scrap copper. The quality can be judged by observing the color and luster of copper. ‌Check the quality of auxiliary materials‌: High-quality wires and cables should use auxiliary materials that meet the standards and avoid using inferior materials. ‌Measure the length of the wire‌: Make sure that the actual length of the wire meets the nominal length to avoid short meters. ‌Check the structure‌: Pay attention to whether there is any trick in the structure of the wire to ensure that the overall quality meets the national standard requirements.