Bryan gives a quick overview of electrical safety basics, including the anatomy of electrocution, arc flashes, and an intro to personal protective equipment (PPE) and lockout/tagout. NOTE: We are not an official OSHA training facility!
Electrocution refers to death or severe injury caused by an electrical current flowing through the body. The electrical path through the body is an important variable in the likelihood of death by electrocution; a current moving across the heart, brain, or spine is most dangerous. Although amperage is indeed what causes death, the power supply type (limited or unlimited current) and voltage also play a role in electrocution; Ohm's law states that voltage is equivalent to amperage multiplied by resistance, and our bodies have high (typically fixed) resistance. The mere milliamps that may pass through our bodies upon electrical shock may be enough to kill or severely injure someone. The duration of the shock is another factor that will dictate the severity of the shock.
To prevent electrocution, work only on safe voltages (24v) without PPE and use proper PPE when working on live higher-voltage components.
Electrocution is not the only risk of working with electrical components. Arc flashes can cause fires, which are dangerous to people inside a building. To avoid being injured by an arc flash, keep a safe distance from the equipment; stay only as close to the equipment as necessary. If you must get close to the equipment, make sure you are wearing all of your required PPE.
Lockout/tagout is another safety strategy that requires you to lock a piece of equipment out at the disconnect while you work on it. Equipment that has been locked out can only start up again if every single person who locked the equipment out removes their lock. If locking out equipment isn't available, then you must tag it out, which alerts others that someone is working on the equipment.
Falling is one of the greatest risks of working on electrical equipment. When you get shocked in a high place, such as on a ladder, you can lose your footing, let go, or fall backward. So, you must also be properly tied off when you are working in high places.
AFCIs and GFCIs interrupt the circuit in cases of arc faults and ground faults, respectively. GFCIs look for imbalances between neutral and hot to protect human life directly, and AFCIs use a circuit board inside the breaker to detect arc risks to prevent fires, protect property, and protect human life indirectly.
The main source of electrical codes and proper installation practices is the NEC/NFPA70. These codes aim to protect human life and property by reducing the risks of electrocution and fires within buildings.
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