Since 2007, generators and transformers in South Africa have played a crucial role in our modern lives, providing electricity to power various industries and infrastructures since we cannot rely on government owned power stations due to load shedding.
However, as much as they have become our saving grace during blackouts, these essential electrical devices also pose significant fire risks if not properly maintained and protected. This blog will delve into the potential fire hazards associated with generators and transformers, explore the necessary fire protection measures, and discuss effective solutions for controlling fires.
Recently, due to the continuous blackouts, there has been an increase in the number of generators and transformers being invested in, by businesses to reduce interruption. Since then, in addition to transformers and fires getting attention, fires caused by generators, even in Sandton City, have been making headlines.
Fires have been reported across provinces and various industries. A fire was reported in Gauteng at a shopping centre in the Vaal, where a generator exploded at the back of the shopping centre causing significant damage to two stores. In February this year, a health centre in Cape Town had to evacuate its patients after a generator exploded.
The below will address possible causes of fires by generators and transformers.
Fire Risks and Causes
Generators and transformers can present fire hazards due to several factors:
- Overheating – A common risk is overheating caused by excessive electrical currents or inadequate cooling systems.
- Very flammable oils used for insulation (mineral oil like) – Transformers are often filled with oil for insulation, to prevent electrical arcing and to serve as a coolant.
- Insulation failure – resulting from age, wear and tear, or environmental factors, can lead to electrical arcing and sparks, which may ignite nearby combustible materials.
- Fuel leaks – especially in diesel generators, can create an additional fire hazard if not promptly addressed.
- Poor maintenance – improper electrical installations, and human error can exacerbate these risks.
Fire Protection Measures
To safeguard against potential fire risks, there are several crucial fire protection measures must be implemented.
- Inspections and maintenance at the required intervals of generators and transformers are crucial to identify potential issues and address them promptly.
- Adequate ventilation and cooling systems must be in place to prevent overheating.
- Fire walls and separation can help contain fires and limit their spread.
- Fire protection systems such as automatic fire suppression systems, sprinklers, or specialised extinguishing agents, should be installed in areas housing generators and transformers.
- Early detection systems, including heat sensors and linear detection cables, should be in place to alert personnel of any potential fire incidents.
- Installation of lightning protection systems to further protect transformers.
Furthermore, it is vital to establish clear emergency response procedures, train personnel in fire safety protocols, and ensure easy access to fire extinguishers and evacuation routes.
Solutions for Fire Control
Proactive measures can significantly lessen fire risks. The solutions below should be discussed with a qualified fire protection company.
Maintenance and inspection
Schedules should be established according to the required intervals as outlined by the manufacturer and industry standards. These would include lubricating movable parts, checking electrical connections, and monitoring coolant levels. Any signs of damage, or abnormal operating conditions should be addressed promptly by qualified professional.
Fire Suppression Systems
Controlling fires involving generators and transformers requires a multi-faceted approach. Automatic fire suppression systems, such as clean agent fire suppression systems, can rapidly suppress fires by chemically interfering with the combustion process without causing additional damage to the electrical equipment.
Clean agents make use of an inert gas or chemical that is stored in a container and discharged when a fire is detected. In areas where water-based suppression may not be suitable, gas-based systems are a viable alternative.
Where water-based suppression is suitable and water supplies are available, a water spray fixed system may be a perfect solution.
Monitoring Devices
Thermal monitoring devices, such as thermal sensors, can detect hotspots and abnormal temperature rises. These devices enable early identification of potential issues, allowing for timely corrective actions before fires occur. Linear heat detection cable’s (LHDC) are designed to provide an early warning detection of fire and overheating in applications where point detectors would not be viable, as transformers and generators are usually installed outside of the warehouse or building.
Fire Walls and Separation
Transformer and generator fires are not ideal and while we try to reduce the risk of fires, in the event one does catch fire or explode we should aim to limit the damage and potential spread of fire. Effective fire containment strategies constructed with materials specifically designed to withstand high temperatures are crucial for limiting the spread of fires.
The NFPA recommends that transformers with more than 1900 L of oil be protected by a fire wall rated for 2 hours that is extended 300 mm vertically and 600 mm horizontally beyond the transformer. As opposed to a fire wall, physical separation is recommended anywhere from 1.5 to 15 m based on the oil capacity of the transformer.
Education and Training
Education and training are vital components of fire safety irrespective of what is being protected.
All personnel should receive comprehensive fire safety training, covering preventive measures, emergency response procedures, and proper use of fire equipment. Regular drills and exercises can improve response times and ensure personnel are prepared to handle fire incidents effectively.
Additional Protection Solutions
Lightning Protection
One of the most common causes of transformer fires are lightning strikes. Although not the lightning capital in South Africa, Johannesburg, and Pretoria, does experience lightning strikes that can be quite damaging, and considering the density of the population and businesses, fire lightning protection should therefore also be considered. For more information on how lightning protection works please visit the NFPA website.
Containment Area
Another important protection feature is a bund wall or containment pit, and a drainage system to help retain any spilt transformer oil or discharge from a fixed water spray system.
Generators and transformers are indispensable for powering our modern world, but failures can be extremely dangerous and without proper fire protection measures, these devices can pose significant risks.
With the right precautions in place fires can be controlled to limit damage to the surrounding components, minimise downtime and improve survival rates of staff and property damage. By implementing effective fire safety protocols, including regular maintenance, early detection systems, and automatic fire suppression systems, we can significantly reduce the likelihood of fires and minimise their potential impact. Let Elite Fire Protection prioritise your fire safety to enjoy the benefits of these essential electrical devices during load shedding with peace of mind.