Magnetic starter: automatic switch for the command and protection of electric motors. The tripping curve of the thermal relay is especially designed for this type of load.
Measuring instrument: a set consisting of the measurement system, the casing and accessories fitted.
Mechanical protection: metal reinforcements are formed by wires or straps of steel or aluminum (unipolar cable).
Midpoint: This is the point of a system of alternating current or single phase, that the intended operating conditions, has the same potential difference, with respect to each of the poles or phases of the system.