Medium voltage distribution feeders are generally not loaded to their nominal rating because of redundancy considerations. During repair of a faulted feeder the loads will be switched to another feeder to limit the customer interruption time. This spare capacity needs to be reserved on each of the concerned cables. To make some of the spare capacity available for increased loading the application of a series controller is proposed. This paper shows simulations of cable distribution systems both with and without series controllers, and compares the results. It is shown how series controllers can increase the maximum loading of distribution systems.