The dispute between the national standard and the non-standard of the cable

Before moving into a new house, everyone will generally inspect the house first, but most citizens will focus on the structure of the house and pay little attention to
the cables in the walls.
If the house is compared to a person, then the cable hidden in the house is a vital "artery"
.
Home improvement cable is not only related to the normal daily life of the family, but also related to the safety of family relatives, inferior cable may cause short circuit, electric shock, cause damage to electrical equipment, and even cause fire, resulting in casualties
.
Nowadays, a large number of non-national standard cables and inferior cables flood the building materials market, and some inferior cables are broken in a pinch and are easier to identify
.
But some inferior cables are exquisitely made, and at first glance seem to be more national than the national standard! So what is the difference between national standard cable and non-standard cable? How to distinguish between national standard cable and inferior non-standard cable?

As we all know, the country has clear provisions on the resistance value of each national standard wire and cable, the most fundamental way to distinguish between national standard cable and non-standard cable is to measure the DC resistance value of the cable at room temperature of 20 °C, the measured resistance and the calculation of the resistance value comparison, to see whether it can be less than the standard requirements (cable a certain wire diameter, conductivity, length is not greater than a certain resistance), the resistance value is less than or equal to the national standard is regarded as in line with the national standard, the resistance value of high voltage national standard is regarded as non-standard cable
。 Since the general consumer, factory, engineering party rarely sent to the quality inspection department for testing when purchasing, secondly, they do not have testing equipment to measure resistance, we should choose the cable according to the use of our own construction site when choosing the cable, do not be greedy for cheap
.
Thought that the cable price is cheap and can be guaranteed to be a national standard, nine times out of ten are brushed
edges.
It is just used to fool those users
who are unprofessional and do not understand the industry.
In order to enable the majority of users to have a clearer understanding of the quality standards of wire and cable and self-judgment of the difference
between national standards and non-standards.
Below we combine the actual situation often encountered by engineering users and the cable industry to let you make a brief understanding
.

Cables and wires, generally used in engineering users and construction projects, mainly have the following three kinds of
cables.
The first is the national standard cable: the cable produced according to the technology of the relevant cable standards issued by the state is referred to as the international line
.
The second is the line standard cable: according to industry standards, there is mainly less cutting corners, but it does not affect the performance of large use
.
The third type is non-standard cable: a product
born to meet the needs of the market.
Nowadays, the application of wire and cable is becoming more and more extensive, and with it, there are more and more types of wire and
cable sold on the market.
So, how should we distinguish between "national standard" and "non-standard" wire and cable? It is recommended that you take one look, two tests, three weighing, four than the price, five look at copper, and six quality tests
.
As long as you skillfully use these six tricks, you can quickly identify the national standard and non-standard
of wire and cable.

A look: we need to look at whether the wire and cable products have a quality system certificate, see whether the certificate is standardized, see whether there is a factory name, factory address, inspection seal, production date, and see whether the wire is printed with trademarks, specifications, voltage, etc
.
Also look at the cross-section of the copper core of the wire, the superior copper color is bright and soft, otherwise it is inferior
.
The fake copper core wire copper core is purple black, yellowish or white, with many impurities, poor mechanical strength, poor toughness, and will break with a little force, and there are often broken wires in the wire
.
During the inspection, you only need to peel off one end of the wire by 2 cm, and then rub a piece of white paper on the copper core, if there is a black substance on the white paper, it means that there are more
impurities in the copper core.
In addition, the shoddy wire insulation looks very thick, but in fact most of it is made of recycled plastic, and over time, the insulation layer will age and leak electricity
.

Second test: we can take a wire head, bend it repeatedly by hand, all soft feeling, good fatigue strength, plastic or rubber feel elastic and no cracks on the wire insulator, is a superior product
.

The third is weighing: good quality wire and cable, generally every 100m weight is within the specified weight range
.
For example, the commonly used plastic insulated single-stranded copper core wire with a cross-sectional area of 1.
5mm2 weighs 1.
8-1.
9kg per 100m; 2.
5mm2 plastic insulated single-stranded copper core wire, weight 3-3.
1kg per 100m; 4.
0mm2 plastic insulated single-stranded copper core wire, weight of 4.
4-4.
6kg per 100m, etc
.
Poor quality wires are not heavy enough, either the length is not enough, or the wire copper core has too many
impurities.
If it is a cable, especially a large-sized cable, the soil method of weighing is the simplest way to reflect whether the copper content of the cable meets the standard and whether the conductor section is sufficient, generally there is a cable with a small section of stealing copper, if the copper content of the cable is weighed to the weight range of the allowable error stipulated by the state, it can basically be identified as non-standard
.

Four to the price: Don't blindly pursue the lowest price
.
As the saying goes, someone does the sale of murder, but no one does the transaction of losing money
.
Some users blindly demand low prices, and want to use brand-name power cords, which forces merchants to sell inferior cables to themselves, the so-called cheap is not good, good goods are not cheap
.
Under the premise of having a certain legitimate profit, I believe that few merchants will exchange high-quality cables for inferior cables, after all, merchants must also take into account their own reputation
.
Inferior non-standard cables are often sold at low prices under the guise of low price and good quality, making people deceived
.
Therefore, when buying, be careful, don't get carried away by the "good quality and low price" advertised by the merchant, and eventually be deceived
.

Five look at the copper
.
Qualified copper core wire copper core should be purple red, shiny, soft
to the touch.
Fake copper core wire copper core is purple black, yellowish or white, many impurities, poor mechanical strength, poor toughness, a little force will break, and there are often broken wires in the wire
.
When inspecting, you only need to peel off one end of the wire, and then rub a little on the copper core with a piece of white paper, if there is a black substance on the white paper, indicating that there are more impurities in the copper core, it can be identified as a "non-standard" wire and cable
.

Sixth, look at quality inspection: In the case of disagreement in cable quality, it can be sent to a third-party testing agency for testing
.
Based on whether the authoritative test report is qualified
.

In addition, there is a view that some of the above cable testing methods are only empirical talk, in the daily testing, usually have to be tested by professional wire testing instruments, such as tensile testing
.