Electric motor reaches thermal equilibrium when the maximum limit of its insulation class

The electric motor can be reversed Zo times for an hour or even the electric motor can achieve thermal equilibrium that is the limit of its insulation class when the electric motor operates in vacuum and is free at any time of inertia and external loads.

Thus, the Zo is called the frequency of reversals to empty and therefore, the electric motor reaches the balance when the electric motor of the empty time.

baldor single phase motor

Both Zo Za and values of the electric motor has a frequency matches the void and is greater than the reversals, but there may be a time when the inertia is added because of the electric motor brake disc.

The electric motor operating on a continuous basis with reversals that include electrical braking.