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Dangers of Electricity

Kupriyanov I.D.

Russia, Vladimir 2017

Dangers of Electricity

Working with electricity can be dangerous. Engineers, electricians, and other workers deal with electricity directly, including working on overhead lines, electrical installation and circuit assemblies. Others, such as office workers, farmers, and construction workers work with electricity indirectly and may also be exposed to electrical hazards.

How Electric Current affects the Body

Electric Current affects the body when it flows through. The basic unit of current is the amp. This is the current which flows through a resistance of 1 ohm (?) when a voltage of 1 volt is applied across it. However, currents as low as thousandths of amps (milliamps) can have an adverse effect on the body. The table below gives an illustration of the types of effects various levels of currents can have on the body.

Effects of Amperage on Electrical Shock

Different amounts of amperage affect the human body in different ways. The following list explains some of the most common effects of electrical shock. To understand the amounts involved, a milliampere (mA) is one thousandth of on ampere or amp. A standard household circuit that supplies your outlets and switches carries 15 or 20 amps.

1-10 mA

The person will feel little or no electrical shock effects or sensation.10-20 mA The painful shock will occur like a jolt, but muscle control will not be lost at this amperage.20-75 mA

This shock is more serious. You'll receive a painful jolt and muscle control will be lost resulting in the inability to let go of something you may have grabbed that is shocking you.75-100 mA

As the current approaches 100 milliamperes, ventricular fibrillation of the heart occurs and damage is done.100-200 mA

Ventricular fibrillation occurs and death can occur if medical attention is not administered quickly. Over 200 mA

Severe burns and severe muscle contractions occur. Your heart can stop during a shock because the chest muscles put pressure on the heart. Internal organs can be damaged at this stage and in you survive, a painful recovery can be expected. What may surprise you about this level of shock is that through this clamping effect on the heart, ventricular fibrillation is avoided and the chances of a person's survival are good if the victim is removed from the electrical circuit.

Dangers of Electricity

Dangers of Electricity include a variety of hazards that include Electric Shock, Psychological Damage, Physical Burns, Neurological Damage and Ventricular fibrillation resulting in death. current shock electric

Any form of energy, when not properly controlled or harnessed, can result in serious danger to those who use it. The risks inherent with electric power can generally be divided into two categories: direct and indirect. The direct danger is the damage that the power itself can do to the human body, such as stoppage of breathing or regular heartbeats, or burns. The indirect dangers of electricity include the damages that can result to the human body as a result of something caused by electric shock, such as a fall, an explosion, or a fire.

Electricity at any voltage can be dangerous and should always be approached with caution. An electric shock can occur upon contact of a human or animal body with any source of voltage high enough to cause sufficient current flow through the muscles or nerves. The minimum current a human can feel is thought to be about 1 milliampere (mA). As little as 80 milliampere, can seize the heart muscle. The current may cause tissue damage or heart fibrillation if it is sufficiently high. A fatal electric shock is referred to as electrocution.

Psychological

The perception of electric shock can be different depending on the voltage, duration, current, path taken, frequency, etc. Current entering the hand has a threshold of perception of about 5 to 10 mA (milliampere) for DC and about 1 to 10 mA for AC at 60 Hz. Shock perception declines with increasing frequency, ultimately disappearing at frequencies above 15-20 kHz.

Burns

Dangers of Electricity include physical burns. High-voltage (> 500 to 1000 V) shocks tend to cause internal burns due to the large energy (which is proportional to the duration multiplied by the square of the voltage) available from the source. Damage due to current is through tissue heating. In some cases 16 volts might be fatal to a human being when the electricity passes through organs such as the heart.

Ventricular fibrillation

A low-voltage (110 to 220 V), 50 or 60-Hz AC current travelling through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60mA.

With DC, 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA, (AC or DC) can cause fibrillation. Fibrillations are usually lethal because all the heart muscle cells move independently. Above 200mA, muscle contractions are so strong that the heart muscles cannot move at all.

Neurological effects

Other Dangers of Electricity cause interference with nervous control, especially over the heart and lungs. Repeated or severe electric shock which does not lead to death has been shown to cause neuropathy.

When the current path is through the head, it appears that, with sufficient current, loss of consciousness almost always occurs swiftly.

Arc Flash

Arc flash and arc blast will always be present on the job, but proper awareness, training and the development of arc flash safety personal protection strategies can minimize the likelihood of injury and fatality.

The leading standard governing the calculation and determination of explosive hazard is the NFPA 70E - Electrical Safety in the Workplace. This electrical safety standard covers the full range of electrical safety issues from work practices to maintenance, special equipment requirements, and installation. In fact, OSHA in the United States already bases its electrical safety mandates on the comprehensive information in this important Standard.

Electrical safety is the leading subject in the North American power industry. Electrical accidents, when they occur (and they occur every day) are extremely debilitating and often fatal, depending on the voltage and amperage involved, as well as the conditions of electrocution. As little as 80,illiamps of electricity is enough energy to put the hu.

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