Description of the laboratory bench

Research carried out on the simulator laboratory bench «Electrical safety of three-phase networks».

On the front panel of the bench there is a mnemonic diagram of the network and its elements, the human figure and other objects, and also has the indicator and switching devices, with which you can set the necessary types of three-phase networks and modes of their work.

Resistance R_АЕ, R_BE, R_CE, R_PEN, capacity С_АЕ, С_BE, С_CE, C_PEN   simulate distributed insulation resistance and capacitance conductors real network relative to earth. R ₀ element depicts the resistance neutral earthing transformer windings. S₁₃ switch allows discrete set these values R_h. Emergency mode, caused by the closure of the supply voltage for the land is realized to the bench by connection R _3M resistance to the phase conductor.

On the right side panel there is a digital display of the ammeter which can measure the current I_h toggle handle installed into the «A1» position and the upper limit of the measuring range set placed next to the switch, depending on the current value. Below is a voltmeter display panel designed for measuring the voltage between ground and the phases A, B and C at the corresponding position of the switch handle.

LED’s glow in the phase conductors indicates the presence of voltage and the LED’s glow in the image of man – the danger (for I_h > 10 mA).

Security measures

1. Connect the bench power supply only with the permission of the teacher.

2. After the end work the laboratory bench must be turned off by toggle switch S₂.

3. If there is a problem turn off the bench from the electricity power network and inform the technician or teacher.

Order of work realization

Carry out a comparative study of three-phase networks with voltage up to 1 kV, insulated and earthed neutral from the point of view of the danger of electric shock to persons.