Nec 690 10(e)

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wyboy

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I am confused about NEC 690 10(E). By definition in 690 .2, a Stand-Alone System is a PV system that supplies power independently of an electrical production and distribution network. NEC 690.10(E) requires breakers to be secured for stand-alone inverters on both stand-alone or utility-interactive systems. Is not a stand-alone inverter, by definition in 690 .2 not a utility-interactive system? Any thoughts?
 
Stand alone inverters can also be interactive. In other words, an inverter could operate as an interactive unit or operate as a stand alone unit when there is no utility power available and batteries are used as the source of power.

Ray
 
But what makes a stand-alone system a stand-alone system if it is utility-interactive?690.10(E) says, "Back-fed Circuit Breakers. Plug-in type back-fed circuit breakers connected to a stand-alone inverter output in either stand-alone or utility-interactive systems shall be secured in accordance with 408.36(D)." By definition in 690 .2, a Stand-Alone System is a PV system that supplies power independently of an electrical production and distribution network. How can a system or inverter be both stand-alone and interactive at the same time?
 
wyboy said:
But what makes a stand-alone system a stand-alone system if it is utility-interactive?690.10(E) says, "Back-fed Circuit Breakers. Plug-in type back-fed circuit breakers connected to a stand-alone inverter output in either stand-alone or utility-interactive systems shall be secured in accordance with 408.36(D)." By definition in 690 .2, a Stand-Alone System is a PV system that supplies power independently of an electrical production and distribution network. How can a system or inverter be both stand-alone and interactive at the same time?
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They are not stand-alone/utility interactive at the same time. This is an interactive system that has the ability to be a stand-alone...i.e. when you lose utility power the system switches over to the stand alone components [battery back up - direct PV usage, etc.].
 
If the inverter is only interactive, then 408.36(D) would not apply. The text reads "circuit breakers connected to a stand-alone inverter output". All the stand-alone systems I've had experience with on dwellings have incorporated the capability of being used as interactive when utility power is available. The only truly stand-alones I've seen are for dedicated pieces of equipment like gate operators.

Ray
 
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