by Michael van Niekerk, ASP Fire -
A back-up power supply such as a genset is critical to reduce overall electricity demand during load-shedding. However, it is vital that such important equipment is maintained properly and serviced regularly to be able to cope with such outages.
Genset failure due to a lack of proper maintenance poses a significant business risk. Here one is not only looking at protecting the value of your assets, but what this genset supports and protects.
The first issue is fuel supply. This can range from an integral tank at the base of the genset to a 2200 l Bulk-to-Farm (BTF) tank or a 210 l drum. The apparent danger is the presence of flammable liquids, especially in terms of refuelling and any spillages.
Another issue is vegetation or combustible material encroaching on a genset, which can often be tucked away somewhere as an afterthought. The genset itself is a potential source of fire ignition due to the high temperatures of the manifold. If the genset is indoors, these temperatures can be considerable, especially if the ventilation is inadequate.
Proper maintenance is therefore essential. If an oil filter has not been screwed on tightly enough, for example, it can result in an oil leak. If oil sprays onto a hot manifold, a fire will ignite. Thereafter the temperature will build quickly to a point where entrance into such a room is well-nigh impossible.
Companies and individuals often lack the correct fire-fighting equipment to deal with genset fires. For example, a dry-chemical fire extinguisher will douse the flames, but not cool down any hot surfaces. A carbon-dioxide fire extinguisher, on the other hand, might cool down the overheated genset itself, but this can damage the equipment due to thermal shock.
Gensets do not only supply standby power but are essential to the day-to-day operations of institutions such as financial services and medical care. Hospitals, for example, will often have back-up gensets, all in the same room. If a fire breaks out in one genset, the rest of the equipment is immediately at risk.
ASP Fire recommends an automatic fire-suppression system for such environments. It is unmonitored equipment, with a high fire hazard due to the presence of both flammable liquids and combustible products, as well as electricity. The probability of something going wrong may be slim in the mind of the end user, but in the likelihood that it does, the consequences can be potentially disastrous and even fatal.
In terms of fixed fire-suppression systems, a range of options is available. Sprinklers are an obvious choice, but this depends on whether such a system has been installed already. If not, the cost can be prohibitive, as sufficient hydraulic capacity must be guaranteed, which means that cheaper and more effective alternatives need to be investigated.
The next best option is a clean-gas fire-suppression system. The problem with gensets and the heat they produce is that the rooms they are in are normally ventilated, which compromises the integrity of the enclosure. If you discharge a gas system in this environment, it is therefore not possible to maintain the concentration of that gas for a sufficient period to suppress the fire. This means that clean-gas systems are not ideal in these scenarios.
The third option is a water- or foam-mist fire-suppression system which only uses a minimal quantity of water. It is also far more cost-effective than the clean gases themselves necessary to recharge the system.
This supresses a fire rapidly, cooling any remaining hot spots down to below the automatic ignition temperature.
A standalone water-mist fire-suppression system with mechanical activation should be inspected monthly. Gensets should by rights be started up at least once a week to ensure the batteries are charged adequately. A cursory visual inspection will also reveal any potential problems or issues.
It is all about risk mitigation, based on how integral the genset is to the business in question. While it is essential for financial service providers and hospitals to invest in the best systems possible, smaller end users also need to look at the impact of genset failure or fire on their businesses.
In terms of regulations and specifications related to gensets, such enclosures are classified as D4 for certain minimum fire-proof requirements, including a specific fire rating for the walls. If the gensets in a building are not located in a purpose-built room and are stuck away in a basement next to parked cars, for example, this is a clear violation of the regulations.
Contact Michael van Niekerk, ASP Fire, Tel 011 452-2169, michael@aspfire.co.za
