Base - May 2004
The electric system is traditionally a single-pole system. The body, the frame, the metal container of electromechanical
components act as equipotential return conductor to the generator, as any point of their metal structure or any negative terminal
not isolated is at the same reference potential or EARTH. This is why the earth has been chosen as reference to the whole system,
conventionally giving it the value of zero.
vehicle in relation to the location of the components on the frame, engine and body.
for electronic devices, a clearly defined earth reference.
current intensity (> 1 A for electromechanical components), from the analogue earth, characterised by wave shapes at
determinate frequencies and very low current intensity (mA, µA) of electronic systems.
compatibility), as parasite signals emitted by the systems on board or outside the vehicle, induce failures and/or deterioration of
the systems themselves. The best solution for a signal earth is connection with the battery negative terminal.
importance to always bear in mind that the satisfactory efficiency of the reference plane or system earth depends on the excellent
conductivity characteristics (contact resistance tending towards zero) in each of its connection points.
electric/electronic components on board, is subdivided into system earth and analogue earth.
IDEAL EQUIPOTENTIAL EARTH NETWORK
Ba. Battery - R. Loads - Rz. Frame impedance - M