Pump Service Disconnects
Pool Design article by Paolo Benedetti, SWD Master
The National Electric Code (NEC) requires a means to disconnect any permanently mounted pump over 1/2 horsepower.
Breakers are known as a branch circuit over-current protection device. According to the NEC 430.109(B) , breakers shall not be used as the disconnection means for motors greater than ½ horsepower. Breakers can wear out over time and lose their overload protection. For motors between ½ and 2 horsepower you cannot rely on the breaker, and you need a seperate means to disconnect the power [NEC 430.109(C)] . This switch or level is called a service disconnect. And for some reason service disconnects are routinely omitted from swimming pool pump owner's manuals and physical installations.
Variable speed pumps are a perfect example as to why a service disconnect is needed. Because they are wired to have power 24/7 and they turn themselves on and off internally through a signal on a low voltage data cable. As is, the only way to turn off the power to the pump is with an NEC approved service disconnect.
To remain in compliance with the NEC, you must install an approved disconnection switch in the line between the circuit breaker panel and the pump - regardless if it is a variable speed pump or a regular fixed speed. The service disconnect does notneed to be expensive. It can be an appropriately rated double pole, double throw switch in a weather resistant box or a lever style disconnect for larger motors.
Paolo Benedetti, SWD Master
Aquatic Technology Pool & Spa
PO Box 130
Morgan Hill, CA 95023
T (408) 776-8220