This article is about Permissible Body Current Limit as per international standard IEEE Std 80.
Permissible Body Current Limit as per IEEE Std 80
The duration and magnitude of current through human body that causes ventricular fibrillation should be less at 50 or 60 Hz.
Duration Formula for Body Current Limit
The duration for which a 50-60 Hz current can be tolerated by most people is related to its magnitude by Eq 3. Based on the results of Dalziel’s studies, it is assumed that 99.5% of all persons can safely withstand, without ventricular fibrillation, the passage of a current in magnitude and duration determined by the following formula:
where, in addition to the terms previously defined, for Eq 3,
Dalziel found that the shock energy that can be survived by 99.5% of persons weighing approximately 50 kg (110 lbs) results in a value of Sb of 0.0135. Thus, ks= 0.116 and the formula for the allowable body current becomes
Note that the above equation results in values of 116mA for 1second and 367 mA for 0.1 second. Since Equation 4 is based on tests limited to a 0.03-3.0 seconds range, it obviously is not valid for very short or long times, and some values of current can be tolerated indefinitely
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