Page 268 - Electrical Safety of Low Voltage Systems

Applications of Electrical Safety 251

FIGURE 15.8 Connection of ECPs at the running rails through a diode.

where I is the leakage current and r corresponds to the radius of the
generic spherical equipotential surface.
Equation (15.1) shows that the electrocution hazard decreases with
the square of the swimmer’s distance from the faulty item, and in-
creases with the square of the radius k, representing the person’s ex-
posed surface to the leakage current, which depends on her/his size. 7
Persons not in contact with the water may still be exposed to the
risk of electrocution when ground faults occur into the pool, as the
earth potential also develops outside of it. The hazard is greater if
persons, who may likely have minimal clothing and be dripping wet,
are in contact with EXCPs (Fig. 15.10).
In the case of Fig. 15.10, the contact with the shower water pipe,
which is at zero potential, exposes the person to a larger touch

FIGURE 15.9 Swimmer exposed to a current field in the water.