8.) The non-use of a locking type disconnect for submersible well pump motors.
Section 430.102(A) requires the installation of a disconnecting means in sight from the motor controller location that disconnects the controller. In the case of the typical residential submersible well pump installation the controller would be the pressure switch on the water storage tank. Section 430.102(B) requires a disconnecting means to be in sight from the motor location to disconnect the motor. Article 100 defines "in sight from" to be visible and within 50' so there should be a disconnecting means that is visible and located no more than 50' from the pump motor. Normally it is impracticable to accomplish this so under the Exception to 430.102(B) you are permitted to eliminate the motor disconnect if the location is impracticable and the controller disconnect is capable of being locked in the open position. The provisions for locking or adding a lock to the disconnecting means shall be installed at the switch or circuit breaker used as the disconnecting means and shall remain in place with or without the lock installed.
Example: a submersible well pump has been installed to supply the domestic water for a dwelling unit. The pump cable runs from the well head to the dwelling unit basement where it connects to the load side terminals of the pressure switch located on the water storage tank. A branch-circuit has been run about 35' from a panelboard that is not visible from the water storage tank location, to a snap switch located next to the water storage tank. The conductors on the load side of the snap switch run to the line side terminals of the pressure switch. In this case the snap switch would be the controller disconnect switch required by 430.102(A). If the panelboard were visible for the entire 35' from the water storage tank location the circuit breaker could also serve as the controller disconnect. There is no disconnect within sight from the well head, in the installation described, so in order to meet the exception to 430.102(B) a device capable of locking the snap switch in the open position would be required. There are products available on the market that will allow a lock to be placed on a standard snap switch assembly or circuit breaker.