Wires and cables are used in all walks of life, so before the purchase of wires and cables, we will understand all kinds of parameters and evaluation through the network way, but many of the online evaluation is not very professional, often cause psychological doubts and worries of users, will be blocked in the purchase. The following is a detailed explanation of our common misunderstanding of cable.
One, wire and cable will there be radiation?
Wires and cables do have radiation, but the fact is that all live things have radiation, such as the 220V wire also has radiation, but the radiation is very small, basically can be ignored, and the radiation of the wire is far lower than the radiation of a mobile phone, if you are really afraid of radiation of the wire, so you can throw away the phone first. The geomagnetic field is even more frightening if you are afraid of the magnetic field generated by electric wires and cables and think that the magnetic field will cause any harm to the human body.
Two, wire square is insufficient unqualified?
This may seem like common sense to a lot of people, but it’s not. As the conductor material production technology improvement and the progress of science and technology, advanced production technology of oxygen free copper has been widely used, copper conductor material resistivity is enough to ensure that use less than the nominal diameter copper wire can meet the requirements of corresponding specifications dc resistance, and resistivity of a conductor of wire and cable conductor have strict requirements, for example, rules of 25 mm square copper conductor at 20 ° dc resistance is not greater than 0.727 Ω / km, so as long as no greater than the value of the conductor is qualified.
Three,the thicker the cable insulation, the better?
Is not the case, can increase the difficulty of cable laying cable insulation is too thick, now give priority to with bridge or wear tube cable laying, many companies are now in the cable requirements, small diameter, has space during the installation process, send out heat, guarantee the cable outer sheath is not damaged, otherwise, bring some difficulties in the construction unit and cable laying. Work in the summer, the temperature will rise, the temperature will be through the outer sheath, and sheath thickness increase, the heat is difficult to send out, will affect the service life of the cable, because of polyvinyl chloride (PVC) under the action of heat, has brought a series of physical and chemical changes in the insulating layer, lost the original fine performance, lead to a significant reduction in the insulation performance, can appear even short circuit, so choosing cable, the thickness of the cable must conform to the standard.
Four,flame retardant cables will not burn?
Is not correct! Flame retardant of wire and cable means that in the event of fire accident of wire and cable, it can block and delay the spread of flame along the wire and cable, so as to minimize the expansion of fire scope of wire and cable. This type of cable has the characteristic of self-extinguishing after fire. Fire-resistant wire and cable refers to that in a fire accident of wire and cable, the wire and cable product can stick to the normal operation for a certain period of time while the external flame is still burning, so as to maintain the integrity of the wire and cable line and the normal operation of the line equipment.
Five, water and electricity laying stress on horizontal and horizontal vertical?
Not necessarily! Although horizontal vertical laying of water and electricity lines look very good, but they are really a lot of hidden dangers! First of all, the material cost of the pipe is much higher than the laying of other ways. Secondly, because it is horizontal and vertical 90 degrees, it is easy to get stuck in the later stage when you wear the wire! So as long as it conforms to the specification!