It can happen to experienced engineers too. Stay carefull.

Injuries caused by electric shocks

The effect of electricity on the body depends on the amount of current and the length of time the body is exposed to it. The higher the current, the less time a human can survive the exposure.

The path of electricity through the body is also critical.

For example, current passing through the heart or brain is more life-threatening than current passing through the fingers. It takes approximately 1,000 milliamps (1 amp) of current to light a 100 watt bulb. Here are the effects you can expect from just a fraction of that current for a few seconds.

The figures illustrate that a small amount of current for a few seconds or more can be fatal (see figure 1).

When a victim is exposed to household voltages, he or she may suffer a muscle spasm and may be locked on to the electrical source until the circuit is turned off, or until the victim is dragged clear, often by the weight of his or her body falling clear of the contact.

Relatively long periods of contact with low voltage are the cause of many electrical fatalities in the home or at work.

At very high voltages (on power lines, for example), the victim is often quickly blasted clear of the circuit. This results in less internal damage, such as heart failure, but terrible surface burns on the body at the entrance and exit of the current.

Note:

All electrical shock and burn accident victims should receive prompt standard first aid treatment, followed by professional medical attention, regardless of the severity.

Notes:

• Electricity always seeks the easiest path to ground. If you touch an energized wire or another energized object and the ground at the same time, you may get killed or injured.
• It must be kept in mind that before any treatment can be given to the victim, the danger must be removed. In some cases, the circuit can be turned off. In other cases, it cannot.

How to Cope with Electrical Injuries

Situation 1:

Cardiac arrest. Heart action may stop if control centres of the heart are paralyzed.

Action:

Start cardiopulmonary resuscitation immediately.

Situation 2:

Ventricular fibrillation. This condition is more likely to be caused by a shock of relatively low voltage. The heart muscles lose the rhythm and throw the heart into spasms.

Action:

Start cardiopulmonary resuscitation immediately.

Situation 3:

Breathing stops. Electric shock often causes breathing to stop.

Action:

Start artificial respiration immediately and monitor the pulse to ensure that blood is circulating. If a flow of oxygen to the lungs can be maintained by artificial respiration until the paralysis wears off, normal breathing will usually begin again.

Situation 4:

Electrical burns. Current passing through the body generates heat and may cause blisters on the skin. If the current is strong enough, it may destroy body tissue and result in severe electrical burns. The outward appearance of electrical burns may not seem serious, but they are often very deep and are slow to heal.

Action:

Standard emergency procedure for burns. Prompt medical attention is required to prevent infection. Examine the victim for an exit burn as well as an entry burn.

Involuntary Muscular Reaction

Involuntary muscular reaction is an effect of electric shock that has been experienced by everyone who has made accidental contact with an electric circuit.

If the current is strong enough, this involuntary muscular reaction can be sufficiently violent to cause serious damage to muscles and bones. In addition to freezing the victim to an energized conductor, involuntary muscular reaction may cause a victim to jump or fall which could result in a more serious injury.

Reference: Electrical Safety Handbook for Emergency Personnel – Energie NB Power