Most generally everyone fears receiving an electrical shock, quite simply because on the occasion th instance can be distressing, physically harming and in some cases fatal.
An electric shock in humans comes about when the human body or parts thereof become/act as an electrical conductor. Fundamentally, the human body comprises mostly a saline solution, i.e. salty water, and since salty water is a fairly good conductor of electricity, so is the human body.
The key parameter when evaluating the severity of an electrical shock is ‘electrical current’ since electrical current constitutes a flow of electric charge, i.e. the movement of subatomic particles.
A further key parameter to consider is electrical voltage, since akin to water flowing (electrical current) through a pipe, electrical voltage can be considered akin to water pressure that provokes water flow.
So given that the conductivity of the human body remains constant, electrical current flow will increase as electrical voltage increases.
Now the kinetics of physical movement of muscles within the human body comes about due to small electrical impulses (electrical current) conveyed and injected into muscles. So when the human body is inadvertently injected with ‘stray’ electrical current, as during the course of an electrical shock, muscles react in a way to oppose or override those electrical impulses conveyed by the human brain. In other more simple terms muscle movement becomes spasmodic.
IEC 60479.1 sets out the magnitude and format of electrical current, that when injected into a human body, those physiological effects that such electrical current over a period of time will bring about.
To simplify, an electrical current of 50 milli-amperes, i.e. 50 thousands of one (1) Ampere will over a period of one (1) second provoke patho-physiological effects such as cardiac arrest, breathing arrest, burns or other cellular damage.
Given analysis of the attached diagram and table we can also comprehend other patho-physiological effects relative to injected current and time.
In conclusion, no one wants to be the receiver/victim of an electrical shock, so I hope the latter may explain and indicate how dangerous electricity is.
Eur Ing Dr Robert Brown (Robert) is a Consultant Engineer in the fields Electrical Electronic and Control Engineering. Robert is also an accomplished professional Expert Witness having prepared and presented many court compliant reports and presented oral evidence within the High Court, Crown Courts and County Courts.For further information please contact Robert via;
Email,…robert.brown@frasergeorge.com or robertbrown@robertbrown.uk.com Tel Land: +44 (0)1709 739228 Tel Mobile: +44 (0) 7976250624