Effects of current on human beings and livestock – Part 5: Touch voltage threshold values for physiological effects
|Publication Date:||1 November 2007|
|ICS Code (Electrical engineering in general):||29.020|
|ICS Code (Accident and disaster control):||13.200|
IEC/TR 60479-5, which is a technical report, provides touch voltage-duration combination thresholds based on analysis of information concerning body impedances and current thresholds of physiological effects, as given in IEC/TS 60479-1. Such threshold combinations relate to specific environmental and contact conditions that determine body impedance for particular current pathways.
This technical report considers only
(i) 50/60 Hz sinusoidal alternating voltage having no other frequency components and no significant direct voltage component, and
(ii) direct voltage with no significant alternating component.
This technical report provides thresholds as a result of calculations based on values from IEC/TS 60479-1, with uncertainties. Therefore thresholds proposed in this report also correspond to values with uncertainties.
This technical report does not consider immersion of body parts and medical application.
Touch voltage-duration combination thresholds are for use by technical committees as guidance for the determination of limits for touch voltage and touch voltage durations in various environmental situations.
Determination of limits needs to be based on risk assessment. Factors that are part of risk assessment include voltage threshold values (taking into account contact area, skin moisture condition, body current pathway) provided by this technical report, as well as other factors not covered such as:
- reduction of the likelihood of contact (by obstacles, barriers, warnings, placing out of reach, training, etc.); or
- reduction of touch voltage compared to the fault voltage (such as by equipotential bonding); or
- additional resistance in series with the human body (such as gloves, shoes, carpet, etc.).