The motor has to have good voltage in order to operate. Improper voltage or voltage surges are the most common causes of electrical heat. The first thing to do is make certain the voltage coming in matches the motor you’re using. The larger the tank, the less the pump starts and stops. Starting and stopping is bad for every component of the system.
Submersible motor manufacturers size wire per the recommended voltage loss in the United States National Electrical Code. You also need to make sure the proper voltage is reaching the motor through good connections, contacts, and proper wire sizing. It’s important to follow all state, local, and national electrical requirements and guidelines.