The power cord is the source of many fires, and the seemingly inconspicuous power cord is often a safety hazard. Choosing high quality power cord is a way to reduce harm. The power cord is usually packaged with the supporting appliances. If you buy a regular brand of electrical power supply in a regular channel, the probability of buying a fake is relatively low. In addition, electrical appliances are generally equipped with after-sales service. If there is something wrong with the power cord, you can also find after-sales service. In order to ensure safety, countries have also formulated some standards to limit the bad production of power lines. How does the country stipulate the standard of power cord?
Appearance standard, certification mark, manufacturer, wire diameter, etc. On the conductor, the yellow-green insulation layer is used for grounding wire.
Second, mechanical strength.
The third is the insulation of the sheath (generally greater than 100 mω) and the compressive strength (below 500V, 1500V).
Fourth, line resistance (no more than a certain resistance under a certain line diameter, conductivity and length).
Fifth, under the impact of high temperature of 150 degrees, the wire will not crack at the low temperature of -30 degrees.
The difference between national standards and non-national standards
The national standard line is 100 0.5m/ volume.
Some are only 60-75 meters/roll without marking.
1, it depends
See if there is a quality system certificate; See if the certificate is standardized; See if there is a factory name, address, inspection stamp and production date; See if there are any trademarks, specifications, voltages, etc. Printed on the wire. It also depends on the cross section of the copper core of the wire. Superior copper is bright and soft, otherwise it is inferior.
2. Try it
It is recommended to bend the end of the wire repeatedly by hand. All products with soft hand feel, good fatigue strength, elasticity in plastic or rubber, and no crack on conductor insulator are excellent products.
Step 3 consider
High quality welding wire is usually within the specified weight range. For example, the common plastic insulated single-stranded copper conductor with a cross section of 1.5mm2, per 100m weight1.8 ~1.9kg; 2.5mm2 plastic insulated single-stranded copper core wire, with a weight of 3-3.1kg per 100m; The weight of 4.0mm2 plastic insulated single copper core wire is 4.4 ~ 4.6kg1300m. The wires with poor quality have insufficient weight or length, or the copper core of the wires has too many impurities.
Step 4 look at copper
Qualified copper core wire copper core should be purple, shiny and soft to the touch. False copper core wire is purple-black, yellow or white, with many impurities and poor mechanical strength and toughness. It will break with a little force, often breaking wires. When checking, just peel off one end of the wire by 2cm, and then gently rub it on the copper core with a piece of white paper. If there is a black substance on the white paper, it means that there are many impurities in the copper core. In addition, the insulation of fake and inferior wires seems to be very thick. In fact, most of them are made of recycled plastics. Over time, the insulation layer will age and leak electricity.
Step 5 look at the price
Because of the low production cost of fake and shoddy wires, vendors often sell them at low prices under the guise of good quality and low price, which makes people fall for it.
Knowing these identification methods, you need to pay attention to buying power cords in the future. Look at the logo, try the quality, weigh it three times, look at the copper and look at the price five times. In fact, it is as simple as choosing a standard power cord. Don't buy a substandard power cord at a low price, and the safety in the future can't be guaranteed. Pay attention to the use of standard power cord when buying. When not in use for a long time, unplug the plug and disconnect the power supply, especially electrical appliances that are easy to catch fire, such as hair dryers and electric ovens.