The cables used in power transmission and electrical installations of buildings are manufactured with 300 Volt to 1 kVolt, with different working conditions and different usage areas. They can be very stranded or single-stranded. They are also used in distribution cabinets and boards, in stationary plants, in a conduit under or over plaster, or in closed dry areas. There are also areas where high temperature is required or in areas where there are no excessive mechanical stresses or under ground.

Some cables are halogen free. These are flame-retardant or multi-core power cables and are generally preferred in high-rise buildings, shopping malls, schools, hospitals, and fire-sensitive areas where people are too crowded. There are mica band on conductors in fire resistant cable types. Thus, in the event of a fire, the transmission of energy continues for the period described in the relevant standards.

Cable Tests

In this regard, the reliability of the cables is extremely important. Not only for human health but also for environmental safety, the cables must pass certain tests. In these tests carried out in the authorized laboratories, both the applicable legal regulations and the standard conditions issued by domestic and foreign organizations are complied with.

These tests are carried out under three main headings: electrical tests, mechanical tests and chemical tests.

1. Electrical Tests for Cables

The cables are ultimately the means of transmitting electrical energy and in this regard, if they are used in the field, they bear high risks. In this respect, the endurance and protection they provide in case of danger is very important. Electrical tests provide important clues about the durability of the cables.

Cables are used in many residential and business centers, hospitals, cinemas and theaters, shopping centers, schools, airports and many other life centers. These cables must meet the following specifications in the event of a fire:

• Must not emit flame
• Flame must not transmit
• The smoke density should be low
• It should not contain toxic and corrosive gas

These features can only be demonstrated by electrical tests. The main electrical tests on cables are:

• High-voltage tests: In these tests, the insulation resistances of the cables under high voltage are tested and determined whether there is a short circuit in the vessels under high voltage.
• Transfer impedance and shield attenuation measurements: In these tests, the shielding quality of the cable is determined. Different frequency ranges are applied in the tests.
• Conductor resistance öDistrict of̈m tests: In these tests, the resistance of the conductor (copper) inside the cables is measured.
• Coaxial cable tests: In these tests, the return losses caused by irregularities and imbalances in the cable are determined.

2. Mechanical Tests for Cables

The purpose of these tests is to measure the resistance of the cables against mechanical forces. Durability and protection of cables are very important in case of any danger. Mechanical tests are performed to determine the durability of the cables.

The main mechanical tests on cables are:

• Ultraviolet aging tests: In these tests, it is determined how durable the cables are against rain and snow water, against sunlight and against humidity. The factors that are counted are formed in the laboratory and their effects are revealed in a shorter time. The cables are also subjected to tensile and rupture tests, as well as visible detections such as cracking, discoloration and tear.
• Hot set test: These tests are applied to cross-linked plastic materials. The values ​​obtained must meet the criteria specified in the standards.
• Tensile strength and tensile elongation test: These tests expose the maximum strength that the materials forming the cable can withstand. The point where the molecular bonds of the material begin to break is the point of withdrawal.

3. Chemical Tests for Cables

These tests measure the resistance of the cables against chemical factors other than electrical and mechanical factors. Chemical tests are carried out to determine the level of resistance of the cables to chemical factors.

The main chemical tests are:

• Determination of the amount of toxicity: These tests are carried out to determine the amount of harmful gas emitted during the fire. The measured values ​​must be below the limits given in the standards.
• pH and conductivity test: These tests are performed to determine how much acidic gas is released during the fire.
• Halogen acid amount test: In these tests, the amount of halogen gas released in the fire is determined.
• Flame oxygen index test: In these tests, it is determined how many and how much the cable can burn with oxygen.