High Voltage Hazards - Ford Electric Ranger 1998 Student Manual

LESSON 3: SAFETY AND EMERGENCY INFORMATION
3-6

HIGH VOLTAGE HAZARDS

This portion of the course will examine the three hazards associated
with high voltage. Later we'll discuss how to avoid mistakes that can
lead to electrical accidents. The three high voltage hazards are shock,
arcing and blast.
Hazard One: Electric Shock
People are affected by electric shock in three ways:
1. Muscle Contraction – A 10 ma, 60 hertz current can cause
muscles to contract. A hand exposed to sufficient electrical
current is unable to release its grip. Chest muscles paralyze and
respiration ceases if sufficient current passes through the chest.
2. Fibrillation – Fibrillation is the disruption of a body's normal
heartbeat. The heart beats because the brain sends it an electrical
signal to do so. Sixty (60) volts are enough to interrupt the
electrical signal from the brain and cause the heart to stop
pumping. The current must follow a path through the body
(hand-to-hand, etc.) in order for fibrillation to occur.
3. Tissue Damage – Tissues within the body and at the current exit
point can be damaged by electrical shock when the current
exceeds 5 amps. Damage to tissue is caused by heat generated
from the current flow. If the energy delivered by the electrical
shock is high, the heat cannot be dissipated and body tissue
is burned.
•
Susceptibility to electric shock varies from person to person,
depending on their physical attributes (skin thickness, etc.).
•
An open cut can reduce a person's natural resistance, and moist
skin will increase the chances of an electric shock taking place.
Even a relatively small electric shock can cause serious injury. A
person's involuntary muscle reaction to a current as low as 3 ma
can result in bruises, bone fractures, and possible death caused by a
collision or fall.
1998 Ranger EV New Model Training