A method for connecting a second motor to a variable speed drive in parallel with at least one existing motor under load and controlled by the variable speed drive is provided. The method disconnects the existing motor from the variable speed drive and a state estimator calculates transient state of the existing motor including at least the speed of the existing motor based on a previously established load model. The method then connects the second motor to the variable speed drive and the second motor is operated using a suitable directive until the actual state of the second motor attains the calculated transient state of the existing motor at a given time. Upon attaining the calculated transient state, the existing motor is reconnected to the variable speed drive such that no current spike is generated in the aforementioned process.