The most frequently asked question by buyers of wires and cables is how to test a cable or how to know if I am buying the right cable.
Here go answers to all the queries you ever wanted to know!
The business of wires and cables is quite expensive which requires good investment and that is why it becomes crucial to test its safety and security. Testing of cables is required for two major reasons, primarily for the safety of buyers and secondarily for the goodwill of the company.
Once all the routes of cable are concealed, the substitution becomes quite challenging. Also, the faults with cables are not always visible, that is why it becomes important for your cable installer to give provision to protect the installed cablings. And this will cost less to you in comparison with changing all the cable in near future.
There are basically three reasons why cables are needed to get tested.
Functionality of cable
Quality of cable
A visual inspection of the cable is a great idea to find any cracks in the insulation, corrosion on the copper, damaged indicators, or moisture on the cable. And many times, fault can be found before any accident or unpredictable situation happens. Faults in cables cost not only unnecessary money but also create disruption. This is the reason why there is enormous demand for cable with different techniques to make sure that cable and joints are in good condition and free of any future mishappenings.
Cable testing is done to predict any fault if there is and then deals with the concern of all those who have been involved in the distribution of electricity. There is a wide range of techniques and types of equipment available to do cable testing for this concern.
There are some of the tests for the electrical power cable.
Persulphate test (for copper)
Tensile test (for Aluminum)
Annealing test (for copper)
Wrapping test (for Aluminum)
Test for Conductor resistance (for all)
Thickness test of insulation (for all)
Overall measurement of diameter test (where specified) (for all)
Let us now see what is done while testing cable:
- Uncovered parts of cables are tested to see any damaged material. Condition of the insulation and exposed jacket is looked over and verification of connection points are matched from what is shown in the project single line diagram.
- Comparison of cable with specifications and drawings. Notation of the cable size, routings and insulation ratings is done.
- The condition of insulation and exposed jacket while performing the visual inspection on low voltage cable and wire is significantly done.
- Looking if the connector is properly rated for the installed cable size and has the proper indentations by the inspection of compression-applied connections.
- Performing an insulation-resistance test on each conductor with respect to adjacent conductors and ground. With the use of a voltage according to the manufacturer’s published data, the test period must be for a minute.
"If you are installing a brand of wire that is well trusted and goes through a proven methodology of quality control, a visual inspection would suffice in order to detect any irregular bending, cracking, crushing, and kinking. Or if there is any fault in the joints," says Shriram Shukla , chief engineer at Valuecon Pvt. Ltd. R&D lab. "However if you are unsure of the quality of the brand of wire, it is advisable to go through other thorough testing methods"