If
electrical systems are not properly wired to remove dangerous voltage,
persons can be subjected to electric shock, which can result in injury
or death.
The National Safety Council estimates that approximately 300 people in the United States die each year because of an electric shock from 120 or 277V circuits. People become injured and death occurs when voltage pushes electrons through the human body, particularly through the heart.
An electrical shock from as little as 50V alternating current for as little as one second can disrupt the hearts rhythm resulting in death in a matter of minutes from ventricular fibrillation.
According to the American Heart Association, ventricular fibrillation (VF) is a life threatening condition in which the heart no longer beats but "quivers" or fibrillates very rapidly - 350 times per minute or more. To avoid sudden cardiac death, the person must be treated with a defibrillator immediately. Cardiopulmonary resuscitation (CPR) provides some extra time, but defibrillation is essential for surviving ventricular fibrillation.
What determines the severity of electric shock?
The severity of an electric shock is dependent on the current flowing through the body, which is impacted by the electromotive force (E) measured in volts and the contact resistance (R) measured in ohms, using the formula is I = E/R.
Electric Shock Values
Electrical Sensation. Tingle sensation occurs at about 0.25 to 0.5 mA for an adult female and between 0.50 and 1 mA for an adult male.
Uncomfortable Sensation. Current over 1 - 2 mA is very uncomfortable to both sexes.
Maximum Let-Go Level. The maximum Let Go Threshold level for a female is approximately - 9 mA and for a male it is about - 15 mA.
The "Let Go" Threshold is the current level where we lose control of our muscles and the electricity causes muscles to contract until the current is removed.
According to the IEEE Std. 80, the maximum safe shock duration can be determined by the formula Seconds = 0.116/(E/R), where R (resistance of person) is assumed to be 1000 ohms.
Article and Picture Credit :mikeholt.com
The National Safety Council estimates that approximately 300 people in the United States die each year because of an electric shock from 120 or 277V circuits. People become injured and death occurs when voltage pushes electrons through the human body, particularly through the heart.
An electrical shock from as little as 50V alternating current for as little as one second can disrupt the hearts rhythm resulting in death in a matter of minutes from ventricular fibrillation.
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| Electrical Shock - Explained |
According to the American Heart Association, ventricular fibrillation (VF) is a life threatening condition in which the heart no longer beats but "quivers" or fibrillates very rapidly - 350 times per minute or more. To avoid sudden cardiac death, the person must be treated with a defibrillator immediately. Cardiopulmonary resuscitation (CPR) provides some extra time, but defibrillation is essential for surviving ventricular fibrillation.
What determines the severity of electric shock?
The severity of an electric shock is dependent on the current flowing through the body, which is impacted by the electromotive force (E) measured in volts and the contact resistance (R) measured in ohms, using the formula is I = E/R.
Electric Shock Values
Electrical Sensation. Tingle sensation occurs at about 0.25 to 0.5 mA for an adult female and between 0.50 and 1 mA for an adult male.
Uncomfortable Sensation. Current over 1 - 2 mA is very uncomfortable to both sexes.
Maximum Let-Go Level. The maximum Let Go Threshold level for a female is approximately - 9 mA and for a male it is about - 15 mA.
The "Let Go" Threshold is the current level where we lose control of our muscles and the electricity causes muscles to contract until the current is removed.
According to the IEEE Std. 80, the maximum safe shock duration can be determined by the formula Seconds = 0.116/(E/R), where R (resistance of person) is assumed to be 1000 ohms.
Article and Picture Credit :mikeholt.com
Safety is always the best policy when it comes to handling electrical equipments and installations. It is very risky if one cannot implement a simple safety measure which could cost a life when not followed. That is why there are online electrician training programs created to provide a guide for those who are planning to enhance their skills in this field.
ReplyDeleteExactly Mark, That's the reason i believe this post will educate so many!!
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