National Electrical Installation Standards

Standards as High as Your Own

Wednesday, January 10, 2018


I have gotten different answers from city inspectors as to when an outside disconnect is required. 230.70(A)(1) says: "The service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance or the service conductors." Is there a limit on how far you can run conduit outside the building without an outside disconnect.

I have often run conduit 20’ from the meter outside the building and then when it enters the building it goes right into the main breaker panel. Most inspectors say there is no limit to how far the conduit can be run outside. However, one recently said I had to have an outside disconnect next to the meter.  Then I can run the conduit as long as I need.

I would appreciate your comments. Thanks, from Kent



Hey Kent thanks for your question. Service disconnecting means can be either outside a building or structure or inside. If inside, it must be located nearest the entrance point of the conductors - where they pass through a wall for example as stated in 230.70(A)(1). The word "nearest" only applies if the disconnecting is inside and no specific length is provided. Compare this wording with that of 225.32 for buildings supplied by feeders or branch circuits. For those the disconnecting means must be nearest the entrance point of the conductors for both outside and inside located disconnecting means. Some areas have local requirements or utility specifications regarding the maximum length of conductor but the NEC does not provide one so the AHJ has to determine what is meant by nearest. Your example of 20 ft of service conductor outside the building is not unusual but as mentioned it must terminate in the service disconnecting means nearest the point of conductor entrance if that disconnecting means is inside.

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