An electrical business in Sibley, Iowa has been fined by the Occupational Health and Safety Administration (OSHA) after an arc flash explosion sent five of their workers to the hospital.
The five workers were working on switching over electrical lines at Timewell Drainage in Sibley when the arc flash occurred. Upon investigating the incident, OSHA found that the workers were installing new electrical wiring to an 800 amp interior panel board when the arc flash occurred. The investigation also found that people were allowed inside the high voltage area without adequate protective equipment, that lockout/tagout procedures weren’t used to isolate the energy source.
As the system was energised when installation was attempted, the resulting arc flash occurred and sent the five workers to the hospital. Many had life-threatening injuries.
Lockout is a process that is enforced whenever maintenance is carried out on dangerous systems and installations to prevent the system from being powered on during this process. General practice in this procedure is to use a lockout device to isolate access to all energy sources that power the system, siphon off all excess energy so no activation can take place and secure the system using a selection of padlocks and clearly-labelled tags. Each employee or a responsible person should be designated with their own padlock and only remove the padlock once they’ve completed their work. Only when every employee is cited for and safely away from the installation should the lockout be removed.
OSHA states that Current Electrical should have conducted regular frequency inspections of all job sites, materials and equipment to ensure workers were protected and had access to the equipment that would protect them from harm. Specialist instructions and training should also have been given to employees to ensure that they had the adequate knowledge to work safely in a high voltage application.
Due to the high level of voltage running through any high voltage application, those working within these environments should always be protected. Although no deaths occurred as a result of this incident, a more horrific result could have easily happened if the arc blast was more potent.
