An important factor that must be considered in the losses is the resistance of the winding when it heats up, that is, when the electric motor starts to rotate in regime of greater power.

The types of losses of the electric motor are: losses in the bearings, by the contacts, in the iron, by friction and by short circuit.

– Losses in bearings occur because the wire has some electrical resistance. To overcome it the energy is converted into heat and not into mechanical force.

– Contact loss occurs because the brushes do not make perfect contact possible when the motor rotates. In fact, the efficiency of this contact decreases greatly as the engine speed increases.

– Losses in iron: When analyzing the operation of a DC motor with brushes, the characteristics of the iron magnetization as the core of the motors must be considered.

– Frictional losses are due to the mechanical characteristics of the motor which must rotate on bearings with the least possible friction. The losses occur because we can not reduce this friction to zero.

– Short-circuit losses occur when the brushes change contact, passing from one winding to another in the motor rotation. drive isolation transformer acme dthb 0145 4s