The Sequence of Electrical Testing For a New Domestic Dwelling
Electrical installation testing is a vital part of the process when building new domestic dwellings. The tests are performed by a qualified professional electrician, with the appropriate equipment. The electrical tests are generally split into two bands – ‘Dead testing’ and ‘Live testing’. This article will outline the sequence of electrical testing for a new circuit, including the insulation resistance, continuity of ring circuits and checking the polarity of the protective conductors (main and supplementary bonding).Find out :eicr-testing.uk
The earth loop impedance test is the first test to be carried out. It ensures that the cable is able to carry enough fault current to trip an MCB or blow a fuse within the regulation guideline times of 0.4 seconds for socket outlets (portable equipment) and 5 seconds for fixed equipment. The results are shown by indicators on the tester, with higher results being better.
Understanding the Sequence of Electrical Testing: A Comprehensive Overview
Next, the polarity of all circuits must be verified. The polarity test is conducted by using a multi tester or continuity tester to verify that there is no break between the point of protection and the point of use. This is particularly important if single-pole switches are installed in the neutral conductor, as this can lead to parts of the installation being connected to a live voltage when a switch is switched off or an over-current device trips.
RCDs are designed to minimise the risk of fatal electric shock when working with electricity. This is achieved by monitoring the balance of current flow between the live and neutral conductors. If a leakage is detected, the RCD will automatically switch off the power within 300 milliseconds – less than the time it takes for someone to breathe or heartbeat. This is an essential safety feature and is why the RCD tests are carried out immediately after the polarity test.
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