To what level should the bearing housing of an electric motor be filled with oil?

The bearing housing of an electric motor should be filled with oil to a level between 1/3 and 1/2. This range ensures that the bearings receive adequate lubrication while preventing overfilling, which can lead to excessive pressure and potential leaks, as well as the risk of foaming, which may impair the motor's performance.

Filling the housing too low may not provide sufficient lubrication, leading to increased wear and overheating of the bearings. Conversely, exceeding the recommended level can cause oil to overflow or become aerated, adversely affecting its lubricating properties. Maintaining the oil within the 1/3 to 1/2 range strikes a balance that promotes optimal functioning and longevity of the motor's bearings.