when it shuts down, how does it restart? do you have to manually reset something such as a breaker or GFCI? As you know, or should know, powering a high current draw device such as a pool pump with an extension cord is not a good idea. Most orange extension cords are only good for about 10 amps of current flow. Te longer the cord gets, the higher the amp draw becomes due to the voltage drop. This voltage drop can cause motors to overheat. The best option for you is to have a proper outdoor receptacle installed near the pool pump following NEC 680 guidelines for pool electrical installations.