Safety Corner: Equipment Grounding
Electricity is a vital part of our daily lives, but it can also be deadly if not handled properly. That’s why it's crucial to understand equipment grounding and its importance in preventing electric shock deaths in the workplace. Today we will explore what equipment grounding entails, the effects of improper grounding, and some controls you can use to protect yourself from electrical hazards.
Before we dive in, I wanted to make a note about the dangers of electrical hazards. Everyone has received a handful of static shocks in their lives, be it from carpet, balloons, doorknobs, or any other number of things (and people) that can build up an electric charge. These give you a “zing” that pricks you but are otherwise harmless. The common misconception is that voltage or amperage alone is what kills you, but it’s more complicated than that. It’s the combination of voltage, amperage, and time that will do it. Voltage is the difference in electrical energy between two points, or the amount of pressure coming from one point to another. Amperage, on the other hand, is how much of that pressure can be released in a single moment. A large pressure difference coupled with a large conduit can result in injury and death. That’s why lightning strikes can kill. But that same difference channeled through a thread would be much less harmful because it can’t deliver the same voltage in the same amount of time. This brings up perhaps the most important aspect of electrical shock, time. The amount of time you are subjected to an electric shock is the real threat.
Assured equipment grounding ensures that all permanent and temporary electrical equipment is properly grounded to prevent electric shock to users and nearby workers. It’s the same While Ground Fault Circuit Interrupters (GFCIs) are often used to safeguard against electric shock, but they do not eliminate the risk entirely. Improper grounding can have severe consequences for human health, ranging from mild tingling sensations to cardiac arrest, internal organ damage, and even death. The severity of these effects depends on the amount of current flowing through the body, as outlined below. These are measured in milliamperes(mA), which is 1/1000 of an amp. These are measured as though the shock lasted 1 second.
1mA: tingling sensation that is dangerous when combined with water or moisture (due to the reduction in resistance).
5mA: Slight shock that can force involuntary action.
6mA – 16mA: painful shock that creates loss of muscle control.
17mA – 99mA: Excruciating shock that can cause muscles to lock, resulting in being unable to let go of a contact point.
100mA – 2000mA: Ventricular fibrillation and nerve damage.
2000mA+: Cardiac arrest, organ damage, 2nd-3rd degree burns, and death.
It's crucial to take measures to protect yourself from electrical hazards by using GFCIs whenever possible, following manufacturers' recommendations, opting for double-insulated tools and equipment, visually inspecting all electrical equipment before use, removing or repairing any defective items, and taking care around outlets wires, and other equipment that carries electrical loads. By prioritizing safety protocols and proper grounding techniques, you can minimize the risk of electric shock and ensure a safe working and home environment for everyone involved.