How dangerous is electrical power?
The effects of electric current on the vital parts of the human body depend on the following:
· Magnitude of the electric current in the body
· Duration of the exhibition
· Electrical resistance of the body.
With respect to the electrical resistance of the body, this varies according to the physical conditions of the subject and the state of his skin (dry or wet).
It is estimated that the resistance of dry skin can be 100 thousand to 300 thousand Ohms per cm2, but this same in a wet skin can be reduced to 1% of these values.
In all electrical installations it is necessary to guarantee the safety of the people who will use it; therefore, it is necessary to provide it with the corresponding protection mechanisms.
When it comes to electrical installations to feed many electrical devices - fixed and mobile - with structures susceptible to deterioration, it is essential to protect against faults in the insulation that cause the appearance of voltages by direct contact.
The stresses by indirect contact originate in the metallic structures of the electrical equipment, when an energized conductor, before the loss of insulation, establishes contact with the metallic structure energizing it.
To minimize the effects of these indirect contacts, every electrical installation must have a protection system. The most effective method for these cases is the grounding system.