(A) All generating units must be equipped with short-circuit interrupting devices consisting of thermal-magnetic overcurrent devices on each phase as well as undervoltage release and solenoid tripping accessories.
(B) Over and under voltage and frequency protection shall be provided to effectively isolate the distributed generation from the utility’s facilities should its power output not be within the utility’s normal operating tolerances. The normal tolerances for under and over voltage are 80% with ten-second time delay and 120% with no time delay of normal. Under and over frequency limits are 58 Hz and 62 Hz with one-second time delay. Frequency relays are not required for solid state inverters which are line commutated.
(C) For distributed generation facilities, primary, ground-fault sensing equipment shall be required to isolate the distributed generation from the utility’s facilities unless otherwise specified by the utility.
(1991 Code, § 14-5-3)