October 16, 2019 by Sam Holland
Electrical safety is a crucial aspect of any electrical engineer’s (EE) career that can, quite literally, be a ‘life or death’ matter. Every day, EEs work with electrical devices and equipment that utilise potentially hazardous voltages. Here’s how to avoid them.
For EEs, workplace safety involves the prevention of physical harm that may otherwise come from the potentially hazardous occupational conditions. It also involves applying the proper safe job procedures (SJPs) and utilising adequate and appropriate personal protective equipment (PPE). Workplace safety is both the responsibility of the employers and the engineers themselves.
Some common electrical hazards at the workplace include:
Electric shock occurs when part of a person's body comes in contact with a closed-circuit or an electrically-charged material. When this occurs, electricity flows through the body towards a ground. Electric shock can cause damage to tissues and vital organs; in fact, at high-voltage installations, electric shock for even a short period could be fatal.
Even household voltage (220V), moreover, is enough to stop a person's heart. To prevent electric shock while working on power-carrying equipment, engineers must apply safe working practices and use the appropriate PPE (more on this shortly).
Electric arcing is an electrical discharge caused by a breakdown of the dielectric material that provides insulation between 2 or more conductors. Electric arcs are common in high-voltage installations where the air gap between conductors loses its resistance and becomes a conductor. Arcs may give off visible light and can cause EMI in nearby RF circuits.
Nips, cuts, and abrasions can occur when engineers (particularly if stressed or fatigued) use the wrong tools for the job, and/or when a part of the body enters a pinch point. The latter occurs when part of an engineer’s body comes between stationary or the moving parts of a machine. This can lead to severe injuries, so engineers must be aware of such potential hazards in their everyday work.
Overheating is commonly caused by short circuits or the utilisation of electronic components that are above their maximum ratings. At power installations, loose terminations can cause cables to overheat; plus, a rapid rise in temperature of electrical devices and equipment can cause varying degrees of burns or explosions. When electrochemical cells explode, moreover, the hot electrolyte can travel considerable distances and cause scalding when it comes into contact with the skin.
A hard hat, which is used for protecting an engineer or other worker’s head in industrial environments. Image credit: Pixabay.
PPE provides a barrier between the engineer and the potential source of harm. Essential PPE for EEs includes:
Head protection: helmets (e.g. hard hats) and bump caps offer protection to the head from the impact of falling objects and bumps. They are especially useful when working in confined spaces.
Eye and face protection: safety glasses and nose masks protect the eyes and face from splurts of liquid, flying bits of metal, and toxic fumes that are generated from industrial activity.
Hand protection: high and low-voltage insulating gloves are made of rubber and provide the engineer’s hands with insulation from electricity. Low-voltage gloves are useful for voltages between 50 to 1,000VAC (volts alternating current), or 75 to 1,500VDC (volts direct current). High-voltage gloves, by contrast, are useful for anything above 1,000VAC and 1,500VDC.
Foot protection: steel-toe safety shoes or boots are special footwear that helps protect the feet from falling objects. While working in industrial environments, every engineer needs to wear a pair at all times to prevent foot injuries.
Understanding and applying basic safety rules at all times can help engineers stay safe, whether they’re working in personal workspaces or industrial environments.
Physical inspection: to prevent electric shock, bodily injuries, and other accidents in the workplace, engineers should perform a routine inspection of their workspaces. A routine physical inspection may include checking and acting on spilled liquids, loose connections, and poor housekeeping (consider the issue of unused tools and equipment that have been left on the shop floor, etc.)
Proving dead: To ‘prove dead’ means to verify that power is disconnected before working on electric equipment. It is vital to isolate or de-energise all energy sources to a piece of equipment and test it with a digital multimeter (rather than simply turning off a switch). At high-voltage installations, it is fairly common for leakage current to flow into a circuit, even when the corresponding switch is turned off.
Lockout-tagout hasps used to isolate energy sources at a power substation. Image credit: Bigstock.
Applying lock-out/tag-out (LOTO): LOTO is a standard safety procedure used to ensure that sources of electrical energy are properly isolated and unable to be restarted until maintenance activities are completed. A LOTO bag contains several lockout tools, such as safety locks, hasps, and seals, alongside their respective caution tags. EEs can use LOTO tools to prevent electrocution and other harm from occurring to themselves and/or other on-site employees.
Several factors can create hazardous working conditions for engineers. Some of the most common causes are human error and exhaustion.
Human error is the biggest cause of accidents in the workplace. EEs who perform repetitive tasks will naturally become familiar with the task after a while. When repetitive tasks are carried out mindlessly, safety rules may ultimately be ignored (or even forgotten), making accidents much more likely to happen. Accordingly, regardless of how often you perform a particular task, you should always give it your maximum concentration to prevent human error.
Working under stress and fatigue is a leading cause of near-misses and accidents in the workplace. According to a late 2018 safety report by the National Safety Council (aka the NSC), up to 69% of workers (including EEs) are exhausted at work. When a person is exhausted, it impacts their ability to concentrate, which can lead to impaired judgement. Sleep deprivation, long work hours, and hot or humid working environments are some frequent causes.
Accordingly, taking the time for short breaks and a healthy night’s sleep after work—alongside wearing the appropriate PPE, and ensuring the correct housekeeping and precautions are adhered to—are all vital measures that ultimately ensure you function at your best, and of course, most safe.
