Range of cable products, offers a modern user is so great that even the experienced master is unable to orient in all this variety. Especially if he read somewhere or heard that a quality product will be able to buy just in case, if we evaluate it in accordance with GOST and technical conditions (TU).
Understand the difference between these two documents will help a little history.
As introduced GOST and TU
Since ancient times, the developers of equipment and power supply systems in their design proceeded from the need to use only high-quality consumables and accessories.
This rule is also applied to the cables, from which largely depended on the stability of supply of public facilities. In this connection was first developed and then put into action the State Standard of the USSR, which was considered mandatory for all issuers national economic production enterprises.
According to this document, each of the products had to meet strictly normalized indicators.
Important! Standard - a standard document of national importance, which are mandatory requirements for all industries and sectors.
It clearly specified technical characteristics of the products, which were to be followed by the manufacturers in their production. Compliance with these requirements, the following special supervisors.
In contrast to the state standards and technical conditions - a document developed at the factory and contains the requirements for a specific type of product. They may be slightly different, but only in so far as that does not violate the rule of the visitors.
What to pay special attention
When selecting a specific sample of cable products is important to monitor compliance with its now producing requirements of GOST. The fact is that today, the manufacturer is trying to save on everything, including the raw materials (copper - in particular). This is facilitated by the absence of strict control, which was observed during the Soviet era in particularly critical sectors.
Therefore, a sample of wire or cable products offered, you may have the following deviations from the standardized GOST parameters:
- Dropped thickness of the coating layer (insulation).
- Introduction to Copper cheap additives impair its electrical conductivity.
- And the most unpleasant - reducing the thickness of a single cable core.
If, according to specifications stated bay cable conductor cross-section of 2.5 mm square. - in reality, it may be less (photo below).
Note: The most interesting thing is that this deviation is not considered a violation of the Standard, since it falls within the permissible values according to technical specifications.
But the magnitude of this error every manufacturer has the right to appoint at its discretion.
What to choose?
Experts recommend that users care about the quality of the work undertaken, to spend a little time and try to find a cable products, labeled in accordance with GOST. This will hopefully on compliance in its production technical requirements at the state level. Doing so is recommended even if there is no significant difference in the proposed cable products prices.
In reality, to distinguish one type of product in appearance from the other (low-quality) is not easy at all. Experts advise to pay attention to the color of copper wires, which have a quality sample to be darker and without luster (photo below).
If the situation does not allow to waste time looking for patterns corresponding to GOST - choose a cable with a thickness of living are taken into account with a small margin.