A sudden power cut can bring any business to a grinding halt. When the lights go out, so do the computers, machinery, and payment systems that keep your operations running. For businesses reliant on a high-voltage (HV) electrical supply, a fault isn’t just an inconvenience—it’s a critical issue that can lead to significant financial losses and safety risks.
Understanding the cause of the outage and knowing the right steps to take is essential for getting your business back online quickly and safely. This guide explains what to do when you suspect a fault in your high-voltage electrical infrastructure, covering everything from initial checks to calling in the professionals.
First Steps: What to Do When the Power Goes Out
Before assuming the worst, it’s important to run through a few basic checks to identify the source of the problem.
- Check with your neighbours: Are other nearby businesses also without power? If so, the fault is likely with the local electricity network provider (the DNO, or Distribution Network Operator). You can usually find outage information on their website or by calling their helpline. If it’s a network issue, you’ll need to wait for them to resolve it.
- Inspect your circuit breakers: If the outage is only affecting your premises, check your main electrical panel. Has a circuit breaker tripped? Sometimes, resetting a breaker is all it takes to restore power. However, if it trips again immediately, it signals a more serious underlying problem that needs professional investigation.
- Look for obvious signs of damage: Without getting too close or touching anything, conduct a visual inspection of your electrical intake area and any accessible equipment. Look for signs like smoke, burning smells, or visible damage to cables or switchgear. If you notice any of these, stay clear and call an expert immediately.
If these initial steps don’t solve the problem, the fault likely lies within your private high-voltage network.
Diagnosing Faults in Your HV Infrastructure
Your business’s private electrical network consists of several key components, and a fault could occur in any of them. Identifying the likely culprit helps professionals speed up the repair process. The most common issues are found in transformers, switchgear, and underground cables.
Transformer Issues
The transformer steps down high-voltage electricity from the grid to a lower voltage that your business can use. Faults can occur due to ageing, overloading, or external factors like lightning strikes or water damage. Signs of a transformer problem include:
- Loud buzzing or humming noises.
- Visible leaks of oil.
- Overheating or signs of smoke.
Transformer failures are serious and require an expert assessment. Do not attempt to inspect or repair a transformer yourself.
Connection and Switchgear Problems
Switchgear is designed to protect your electrical equipment, but it can also be a point of failure. Connections can become loose over time, or the internal components can degrade. Regular maintenance can often prevent these issues, but if a fault occurs, you might notice flickering lights or intermittent power failures leading up to a full outage. An authorised electrical engineer will need to test the equipment to find the exact point of failure.
High-Voltage Cable Faults
Underground cables are a common source of high-voltage faults. Despite being buried and protected, they are vulnerable to damage and degradation.
A cable fault can be caused by several factors:
- External damage: Accidental strikes from excavation or construction work are a leading cause.
- Moisture ingress: If the protective outer sheath of the cable is compromised, water can seep in and cause the insulation to fail, leading to a short circuit.
- General wear and tear: Over time, the materials that make up the cable can degrade, especially if the cable is old or has been under stress.
- Manufacturing defects: Although rare, imperfections in the cable can lead to premature failure.
Locating an underground cable fault requires specialised equipment to pinpoint the exact location. Once found, the damaged section is excavated and repaired. This often involves a process known as cable jointing, where a skilled technician cuts out the faulty section and joins a new piece of cable to the existing ends, ensuring a secure and durable connection.
The Importance of a Professional Electrical Emergency Response
When dealing with high-voltage equipment, safety is the absolute priority. Attempting DIY repairs is not only extremely dangerous but can also lead to further damage and more costly fixes.
A professional electrical emergency response team has the training, authorisation, and equipment to work safely on HV networks. They can:
- Safely isolate the power supply.
- Use diagnostic tools to accurately locate the fault.
- Carry out repairs efficiently, whether it’s fixing a transformer or repairing a cable.
- Test the system thoroughly before restoring power to ensure it is safe and stable.
Get Your Power Back On
A high-voltage fault is a serious disruption for any business. By understanding the potential causes and knowing the correct procedure, you can manage the situation safely and effectively. Remember to perform initial checks, but never compromise on safety. For any issue beyond a tripped breaker, leave it to the professionals. Their expertise is your fastest and safest route back to business as usual.
