The lower the resistance value of the connector, the greater the conductor's ability
to withstand the electric current without thermal effect.
Each resistor is measured for a sample of cable length not less than 1 meter Check the electrical resistance of the connectors.
Resistance is measured using a micrometer or milliometer device.
The measured values should not exceed the values shown in the map that are equal to the area of the section.
Measuring the insulation thickness of the cable in two steps:
A- Measurement of the thickness of internal insulation :-
It takes three samples of the wire from three different locations along the cable.
1- cutting circular strips of insulation
2- The thickness of the insulation shall be measured by a porthole device
3- The thickness of the insulation shall be determined and compared to the prescribed tables according to the area of the cable section.
B- measurement of thickness of the casing: - where three samples of the cable cover are taken from three different positions along the cable
1- cut strips of circular cover
2- The thickness of the casing shall be measured by a porthole device
3- The thickness of the envelope shall be calculated according to the grade.
As insulation resistance increases, protection from tingling or contact leading to electric spark -
This test is carried out on samples length of 5 meters
In which the cable is immersed in the water after heating to the specified temperature (70)
The voltage is 500 volts( DC) measured and the insulating resistance shall be not less than the values indicated by the meter according to the area of the cable section.
High voltage testing of finished cables.
Electrical durability (the higher the insulation of the high voltage the greater the protection from increasing the financial effort).
This test is carried out on samples length of 10 meters for finished cables 5 meters to the poles and in which the cable is immersed in water
1. A voltage of 2500 volts is transmitted alternately between each conductor and the other conductors connected to each other.
2. The voltage is set for 1 minute
3. At the end of the test, there shall be no collapse of insulation.