Normal operation mode of electrical network

Task 1. To investigate the dependence of the current passing through the human body with direct contact to the phase wire from the insulation resistance network with insulated wires, and then earthed neutral at a constant value relative to earth capacitance of wires, observing the condition: R_AE=R_BE=R_CE=R_PEN and C_AE=C_BE=C_CE=C_PEN.

Voltage U_ph = 220 V, R_h =1000 Ohms, the values of R should be taken in accordance with the nominal values indicated on the bench front panel near S₄ – S₁₁ switches. The measurements results should be recorded in the table 8.3 form of the report of the laboratory work (sample report form see in the table 8.3). Draw a graphs I_h = I(R).

Table 8.3.

The dependence of the current I_h, mA, on resistance R, Ohm,
 of insulation wire network when R_AE=R_BE=R_CE=R_PEN and C_AE=C_BE=C_CE=C_PEN .

RAE=RBE=RCE=RPEN, kOhm   IhmA,	∞	1.0	2.5	10	25	100
Isolated neutral mode
Earthed neutral mode

Task 2. To investigate the dependence of the current passing through the human body with direct contact to the phase wire from the wiring capacitance relative to earth in isolated and then earthed neutral at a constant value of insulation resistance of wires, observing the condition: R_AE=R_BE=R_CE=R_PEN and C_AE=C_BE=C_CE=C_PEN.

Voltage U_ph = 220 V, R_h =1000 Ohms, the values of R and C should be taken in accordance with the nominal values indicated on the bench front panel near S₄ – S₁₁ switches. The calculation results recorded in the table. 1 and 2 of the report of the laboratory work (sample report form see in the table 8.3). Draw the graph I_h = I (C).

Table 8.4.

The dependence of the current I_h, mA, on capacity C, μF,
 of insulation wire network when R_AE=R_BE=R_CE=R_PEN and С_AE=С_BE=С_CE=С_PEN

Task 3. To investigate the influence of the resistance of the human body circuit R_h on I_h current flowing through the person touching the network phase conductor with insulated and earthed neutral, during normal network operation.

The experiment results should be written in the report (table 8.5) of laboratory work and build graphs I_h = I (R_h) for both types of networks.

Table 8.5.

The dependence of the current I_h, mA, on voltage U_A, V
and resistance of human body R_h