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Touch voltage and Step voltage | Touch potential and Step potential

Touch voltage (or Touch potential) and Step voltage (or Step potential) are the significant term of electrical power system and mainly in electrical substations.

Touch potential (Touch voltage):-

As shown in above figure, suppose there is a structure which is faulted and fault current flowing towards ground through that structure. If a person standing on ground raises finger and touches that faulted structure than potential or voltage difference between that person’s finger and feet known as Touch potential or touch Voltage.

Step potential (Step voltage):-

At the time of fault suppose one person is moving on substation ground, at that time potential (voltage) between two steps of that person is known as Step potential (Step voltage).
This Touch potential (Touch voltage) and Step potential (Step voltage) should be below 45V. so that a person working in electrical substation does not get shock.

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