Common signs of an electrical fault are lights flickering or appliances stopping working with no warning. You can often encounter these in a commercial or industrial property, but it requires a professional electrician and a systematic process of electrical fault finding to locate, identify and resolve the problem. This is because electrical faults can present serious safety risks if you are not qualified and don’t have the knowledge to understand them.
So electrical fault finding is a methodical process that an electrician will go through to find a problem rather than randomly testing components in the hope of finding the source of the issue. This systematic process helps the electrician rule out certain potential problems in sequence, which leads them to the root cause of an issue, and always while maintaining safety compliance. Electrical fault finding involves using specialist test equipment and undertaking a range of diagnostic tests in order to trace the source of the problem.
What are the common electrical faults?
Electrical fault finding is usually trying to identify one of the following common faults:
- Circuit overloads – Too many appliances drawing power from a single circuit and exceeding its capacity.
- Short circuits – When a live wire contacts a neutral wire or another live conductor and creates a dangerous current surge.
- Earth faults – When damaged insulation, a damaged appliance or moisture allows current to find an unintended path to ground.
- Loose connections – Loose terminals caused by vibration or poor installation, which can lead to fire risk and component failure.
- Cable damage – Physical damage to a cable which can cause intermittent faults.
- Faulty appliance – Circuit breakers in an appliance can trip through internal wiring faults or component failures.
How electricians carry out the fault-finding process
The key objectives behind the electrical fault-finding process are to find a fault safely and while causing minimal disruption to the electrical system. This requires a structured approach to maintain a strict order of sequential testing. The process should involve:
- Consultation – Information gathering on the problem, symptoms and what appliances or circuits are affected, in order to guide the subsequent testing.
- Visual inspection – Looking for obvious signs of damage, hazards or failure and checking the general condition of the electrical installation. This can influence how the testing process continues and what additional work may be required.
- Isolation – Switch off relevant circuit breakers and verify suitable isolation, including to prevent accidental re-energisation.
- Testing methods – Select appropriate test methods based on the fault symptoms and installation characteristics identified in the initial stages. Common tests will include continuity testing, insulation resistance testing, earth loop impedance testing, RCD testing and voltage drop testing.
- Diagnostic approach – While testing, the electrician will adopt a logical strategy to locate the faults quickly and safely. This involves dividing circuits or systems into sections to quickly eliminate large portions of the installation. Another approach is to follow electrical paths from supply points, through distribution boards and circuits and to the outlet point. The electrician will also temporarily replace suspected faulty components to confirm a diagnosis and will generally use a process of elimination to find the root cause of a problem.
Once a fault has been located, it will be rectified and the installation or appliance verified as safe and operational, before being released from isolation and put back into general use. Common test equipment used to carry out electrical fault finding can be sourced through Test Instrument Solutions, and includes multi-function testers, multimeters, clamp meters and thermal imaging cameras.
Please note that this section is for information purposes only. Anyone using equipment referred to in this section must be suitably qualified and/or experienced within the respective field. If in doubt before use, please consult a qualified electrician or engineer & thoroughly read all instruction booklets.