Polo star

Polopole. Tool that allows verifying if a certain cable or conductor presents a potential difference (voltage) with respect to the physical earth .


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  • 1 Description
  • 2 Use
  • 3 Classic conceptual error
  • 4 Consistency
  • 5 Sources


The pole finder is a tool that allows verifying if a certain cable or conductor presents a potential difference (voltage) with respect to the physical earth (for example, in household electrical outlets, it identifies which cable is the “phase” or “live” “). It consists of an open circuit consisting of one or more lamps, and has suitable contact tips for searching.


The correct way to use this tool is by making contact with the metal tip on the conductor to be analyzed, and at the same time touching the other end of the pole finder with your finger. If one is in contact with any surface that acts as earth (in any way, either by being barefoot or being worn by the capacitive reactance between our body and the earth), the circuit through our body is closed in this way and This turns the lamp on. It can be seen that it is not strictly necessary to be in direct contact with the earth for the search engine to light its lamp; if for example one climbs on an insulating material such as a chair, or directly “jumps” during the test, you can verify that the lamp does not go out during the time that one is not in contact with the ground.

There is no risk of receiving a dangerous discharge through the pole finder, since the resistance of the internal lamps is very high, and in this way a very small current circulates, harmless to our body, but enough to generate light.

Classic conceptual error

Concepts should not be confused; the pole finder does not individualize the positive pole, since it as such does not exist in an alternating current circuit. The polarity of a 50/60 Hz alternating current circuit (depending on the region), such as the home electrical network, changes the polarity exactly 50/60 cycles per second, so that one cable can never be positive and another the negative continuously. What happens is that the search engine identifies the cable called “phase”, which has, if continuously, a potential difference with respect to the physical earth. It thus differs from the other cable (in two-phase installations) called “neutral”, which, being grounded by electric power companies, has almost the same electrical potential as physical earth (actually,neutral wire and ground, but usually does not exceed 5V in the worst case).

The individualization of the phase is very useful when making new electrical installations or bypassing existing circuits, since the regulations foresee that the phase conductors differ from the ground and neutral conductors. In addition, this search is used to identify faults or malfunctions in the equipment and its metal cabinets.


They can be found in the form of a serial lamp, or in the form of a screwdriver , the latter being the most widely used.


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