Service manual

STP 11-25R13-SM-TG
T - 2
Technical information and assistance in determining the advisability of granting waivers may be obtained
by communicating with COMMANDER, US ARMY COMMUNICATIONS-ELECTRONICS COMMAND
AND FORT MONMOUTH, ATTN: DRSEL-SF-E, FORT MONMOUTH, NJ 07703.
T-7. Reporting.
Accidents causing injury to personnel or equipment damage shall be reported by the local safety
office on DA Form 285. See AR 385-40 for specific requirements of accident reporting.
Section II. ELECTRICAL/ELECTRONIC EQUIPMENT
T-8. General.
The term HIGH VOLTAGE is used in many instructions without specifying where low voltage ends
and high voltage begins. It is important to note that voltage is only the electromotivating force pushing the
current. It is the current that kills, not the voltage. For the purpose of this technical bulletin, greater than
500 volts rms (root-mean-square) or greater than 500 volts direct current (DC) is defined as HIGH
VOLTAGE; and a current of 25 amperes or more is defined as HIGH CURRENT. Do NOT be misled by
the term LOW VOLTAGE. Under adverse conditions, much lower potentials may cause death, and
voltages as low as 30 volts can be considered dangerous.
T-9. Physiological Effect of Current Flow.
A detailed discussion of the physiological effects of electric shock is beyond the scope of this
bulletin; however, it is important to outline the key factors which play a role in determining the relative
hazards of shock from different types of electrical discharges through the human body. In various
studies, it has been determined that several factors are of importance in determining severity of injury
associated with electrical shock.
a. The current path through the body.
b. The frequency, if alternating current.
c. Susceptibility of heart in the different phases of the cardiac cycle.
d. Duration of the shock or discharge.
e. Repeated shocks in different phases of the heart action.
f. Current magnitude.
g. Skin resistance, and whether voltage is sufficient to break down skin resistance.
T-10. Levels of Effect.
a. It is well known that current, not voltage, determines the physiological effect. It is useful to
distinguish quantitatively between at least four levels of effects due to continuous current:
(1) Nonperceptible electrical current.
(2) Perceptible (perhaps painful) currents below the let-go-threshold.
(3) Currents above the let-go threshold.
(4) Currents that cause ventricular fibrillation (discoordinated heart action).