Risk of Fire in Old Factor Correction Assemblies The purpose of this Safety Alert is to highlight the risk of fire in old power factor correction assemblies. Power factor correction assemblies are used by large business and factories to mitigate the electrical network effects of inductive machines, such as electric motors, refrigeration systems and air-conditioning. Background A recent fire at a factory in Darwin revealed a number of old power factor correction assemblies installed in 1999. The capacitors contained within the assemblies have a rated life of 130,000 hours. Investigation of a fire in one such assembly found the capacitors had been in constant use for 150,000 hours, and had exceeded their design life. Multiple protective devices were installed within the assembly to guard against catastrophic failure, however these were unable to prevent an explosion in a capacitor resulting in a cascade failure and conflagration causing massive damage to factory infrastructure. Contributing factors Capacitors have a limited life expectancy. Heat may accelerate aging effects on capacitors. Fire may result in old capacitors without warning. Action required Audit power factor correction assemblies to ensure operation only within designed life expectancy. Arrange for an electrician to inspect capacitors annually for signs of bulging or leakage. Replace capacitors which appear to be failing or have reached their life expectancy. If possible locate power factor correction assemblies away from critical infrastructure. Disconnect the factor correction assemblies from supply if urgent repairs may be delayed. Further information Legislation Electricity Reform Act - Section 68 - Responsibility of owner or operator of installation. Work Health and Safety (National Uniform Legislation) Act Section 21 - Duty of persons – conducting businesses or undertakings involving management or control of fixtures, fittings or plant at workplaces. Guidance publications AS\NZS 3000:2007 Wiring Rules Clause 4.15 - Capacitors. –
Risk of Fire in Old Factor Correction Assemblies The purpose of this Safety Alert is to highlight the risk of fire in old power factor correction assemblies. Power factor correction assemblies are used by large business and factories to mitigate the electrical network effects of inductive machines, such as electric motors, refrigeration systems and air-conditioning. Background A recent fire at a factory in Darwin revealed a number of old power factor correction assemblies installed in 1999. The capacitors contained within the assemblies have a rated life of 130,000 hours. Investigation of a fire in one such assembly found the capacitors had been in constant use for 150,000 hours, and had exceeded their design life. Multiple protective devices were installed within the assembly to guard against catastrophic failure, however these were unable to prevent an explosion in a capacitor resulting in a cascade failure and conflagration causing massive damage to factory infrastructure. Contributing factors Capacitors have a limited life expectancy. Heat may accelerate aging effects on capacitors. Fire may result in old capacitors without warning. Action required Audit power factor correction assemblies to ensure operation only within designed life expectancy. Arrange for an electrician to inspect capacitors annually for signs of bulging or leakage. Replace capacitors which appear to be failing or have reached their life expectancy. If possible locate power factor correction assemblies away from critical infrastructure. Disconnect the factor correction assemblies from supply if urgent repairs may be delayed. Further information Legislation Electricity Reform Act - Section 68 - Responsibility of owner or operator of installation. Work Health and Safety (National Uniform Legislation) Act – Section 21 - Duty of persons conducting businesses or undertakings involving management or control of fixtures, fittings or plant at workplaces. Guidance publications AS\NZS 3000:2007 Wiring Rules – Clause 4.15 - Capacitors.
safety-alert-risk-of-fire-in-old-power-factor-correction-assemblies.docx