Allowable values of current flowing through the person

These values I_h, U _c provide an opportunity to allow the assessment of the risk of injury and to develop means of protection (earth and neutral, protective earth, safety shutdown, etc.).

Hazard analysis of electrical networks is to determine the current flowing through the human body:

I_h =U _1,2 /R_h,                                                                             (8.3)

where U_1,2 – voltage between points 1 and 2, which touches people directly or through some intermediate elements; R_h – resistance in the electrical circuit of the human body.

When the two-phase touch U_1,2 = U_l  and

                                         I_h =U_l /R_h,                                                                (8.4)

In this case, the current is determined by line voltage and the resistance R_h and practically independent of the neutral network mode. A sufficient increasing R_h (for example, when using dielectric gloves) provides an opportunity to avoid injury. Otherwise R_h =1000 Ohms and U_l = 380 I_h reaches 380 mA, that when τ> 0.1 is very dangerous.

When you touch a single-phase, if a person is shod and on any basis:

R_h = R _h+ R _sh +R _b ,                                   (8.5)

where R_h, R_{s h} and R_b – the human body resistance, the shoe and the base, respectively.