Insulated wire commonly known as rubber line, according to insulation materials can be divided into rubber and plastic (PVC) insulated wire, according to the core material can be divided into copper and aluminum core wire two. The insulation layer of many wires is not made of normal insulating plastic, but is made of recycled plastic, and the insulation layer can be peeled off by light peeling, which can easily cause the insulation layer to be broken down by current and cause life safety. Great threat. The thickness of the conductive core determines the load of the wire on the current. The larger the current, the thicker the conductive core is. However, the actual cross section size of many wire cores is much smaller than the size they indicate. For example, many wires are said to have a core cross section of 4 mm2, but only 2.5 mm2 are measured, and some are even 1.5 mm2. When using this kind of product, it will cause excessive heat resistance and cause the danger of electrical fire. So when purchasing, you can refer to these methods: 1, look at the label printing samples, the address is unknown. Refers to the label on the label and the insulating cover. If there is a typo or a different shade of printing or the words are fuzzy, you must pay attention. 2. Insulate the skin with a hand, fade, drop the word quality. Refers to rubbing the insulation skin with your fingers. Some poorly insulated wire covers are easily discolored. This is especially true for red lines. After the rubbing, the skin color on the finger or the word printed on the skin is rubbed off. It is generally a poor quality line. 3, then use nails, squatting line, draw down, off the skin in general. It refers to the use of fingernails and enamels to insulate the skin. It is generally a poor quality line that can be drawn down and smashed down. 4. Repeatedly bend the insulated wire and break it three to four times. Refers to the repeated bending of the insulated wire, poor quality of the general poor insulation material, after bending 3-4 times the insulation layer will break. 5. Insulate with the fire ignition wire and leave the open flame fire spontaneously. It refers to the ignition of the insulating layer, and it is the inferior line that can spontaneously ignite after leaving the open flame. 6, the core is commonly used in aluminum and copper, the color is dark and light. Refers to the color of the core. The color of the inferior line is dark and has no metallic luster. 7, a fine inner diameter and outer diameter, see the weight of Pison. It means that if the above six methods cannot be determined, the outer diameter and the core diameter of the insulated wire can also be measured. The allowable error is ±10%. If the measured value exceeds the allowable error, it is basically an inferior insulated wire. Electric appliances Compression Spring,Coil Springs,Coil Spring Compression Springs Compression Spring Co., Ltd. , http://www.nsspring.com