NYM power cables belong to the category of electrical connectors made of copper. Their main task is the implementation of internal wiring. Lay in various building structures, including fire hazardous ones. Originally made and used only in Europe. Today in Russia there are several factories specializing in the production of power cables according to their own specifications.
Description and interpretation
The NUM wire is a cable product that is widely used for lighting and domestic purposes, as well as stationary power, where the voltage indicators are not more than 0.66 kV at frequencies of approximately 50 Hz.
Installation of an electrical product is possible inside dry and humid rooms, in a humid environment and in an open space, but only with strict observance of the required level of protection against ultraviolet radiation and mechanical stress. For safe operation use corrugated pipes, metal hoses and cable channels. It is not forbidden to hide power cables under the layers of plaster or lay on top of it, in concrete or brickwork.
It is forbidden to press the power wire of the NUM type into vibration-filled or stamped concrete.
Explanation of the NYM marking:
- N - belonging to the classification of Normenleitung cable products, quality meets German standards.
- Y - in the production we used an insulating material - polyvinyl chloride or PVC plastic.
- M - installation in different conditions is possible.
On the insulating surface, the VDE marking must additionally be indicated, which indicates that the particular product is manufactured in accordance with German industry standards Veiband Deutscher Electrotechniker 0250 and can be used in areas with an increased risk of emergency situations.
Design Features
NUM wire can only be made of copper. The shape of the section is round. It has the following arrangement of elements:
- Current-carrying conductor made of high-quality copper. The number depends on the modification of the wire, there can be from 1 to 5 conductors. The cross-sectional area of the veins is also variable, the value varies between 1.5-35 mm.kv.
- Insulation of conductors is made of high-quality plastic alloy - polyvinyl chloride. The surface of the material may have a different color depending on the number of cores and purpose.
- Sealing material that is made from unvulcanized finely filled rubber. Its main task is to prevent the penetration of moisture into the internal cavities and to provide high-quality additional insulation. Due to this design feature, the NUM wire is not subject to burning. It only melts and holds a round shape.
- The outer shell, which is made of plastic sheet type. Its function is to protect conductive veins from aggressive substances and mechanical stress. Its limits determine the total cross-sectional area. This parameter indicates the ability to use an electrical product in trays, voids and niches.
The layer between the insulating and sealing material is necessary for the convenience of cutting and increasing the flexibility of the product, as a rule, has a white color.
Benefits of using
The main advantages of power cables:
- High degree of elasticity. The rubber layer located between the sealing and insulating layer gives flexibility.This allows you to rationally use the product in hard to reach places and underground.
- The cable is made of non-combustible materials, so it is recommended to use it in fire hazardous building structures.
- High quality. Before going to store shelves, each cable undergoes various tests.
The NUM wire has a large number of advantages that experts from the field of electrical installation note. Especially often they are used to implement power and lighting purposes.
Varieties of NYM Wire
The wire mark is made in several modifications - NUM-J and NUM-O. They have identical specifications.
Power cable specifications
To determine whether it is possible to use one of the varieties of NUM power cables, it is required to familiarize themselves in detail with their technical characteristics.
- The value of the rated voltage. It can be operated in electric lines with a supply voltage not exceeding 660 V and a frequency of 50 Hz.
- The bending radius should not be more than 4 outer diameters of the electrical product itself.
- The rated operating current is determined by the cross-sectional area of the conductor, the maximum permissible current value, which can flow for a short time in case of emergency or emergency situations, depends on this parameter.
- The resistance of the insulating material determines the dielectric properties of the material used.
- Operating temperature is the temperature range at which the wire can perform its functions without destroying the elements and losing the specified network parameters. For NUM wires, the temperature ranges from - 50 to +50 degrees Celsius.
- The resistance of the core is determined individually in each case during the test, determines the permissible amperage and throughput.
If there are difficulties when choosing a cable, it is best to consult a specialist from the store.
Analogs of the wire NUM
In Russia, the main counterpart at a more affordable cost is the domestic brand VVG or VVGng in non-combustible performance. Their main difference lies in the shape, at NUM it is always round, and at the domestic analogue it is flat. This is an additional advantage, since this form simplifies the process of laying in technological holes and contributes to better tightness.
Major manufacturers
If the budget is limited when purchasing a power cable, you should pay attention to domestic developments, the quality of which is not inferior to international standards, and the cost is much lower. Among the main domestic manufacturers should be highlighted:
- Pskovkabel;
- Sevcable;
- Camcable;
- Concord.
If we consider foreign manufacturers, all of the required quality certificates and delivery to Russian markets are in the following:
- Turkish Denizli Cable LTD.
- Serbian Novkabel AD.
- French Nexans.
- German manufacturers: TKD Kabel, Kabeltec, Lapp Kabel.
Non-combustible power cable NUM is actively used in both industrial and domestic electrical installation works. It is indispensable for wiring in wooden structures, as well as on the street. However, the material is afraid of ultraviolet radiation, so direct sunlight is contraindicated.
At home, NUM wires are used for switching lighting lines and connecting outlets. It is also not forbidden to lay an electrical product in the ground, but previously experts recommend threading the product into a metal hose or corrugation.
To exclude the likelihood of acquiring low-quality goods, it is better to buy it in large construction stores or from official representatives. It is recommended to check the quality certificate, the availability of supporting documentation.
