The conductors that run from the service connection point with the electric utility to the service disconnect (main breaker) in the service panel are the service conductors. Service conductors are sometimes confused with feeders. Feeder conductors connect the load side of the service panel, or other downstream panel, to the final overcurrent protection device (breaker) for a branch circuit. So, for example, the cables connecting a service panel to a subpanel are feeder conductors. 

    It is important to know the difference between service conductors and feeder conductors, because a raceway/conduit with service conductors cannot be shared with feeder or branch service conductors. The reason for this is that service conductors do not have overcurrent protection, and a short between a service conductor and adjacent feeder or branch conductor in the same raceway may bypass any overcurrent protection for those circuits. Also, it is not allowed by the National Electrical Code (NEC 230.7).

    The example shown above, with cables coming into the panel to a main disconnect below and branch circuits cables exiting through the same conduit, would be wrong if it is a service panel, but alright if it is a subpanel under certain circumstances. See our blog post What are the requirements for NM-cables entering an electric panel box? for more on that.

    Also see our blog post Can you use an electrical panel as a feed-through raceway for wiring that is not connected it? 

    Please note that none of this information is meant to advise homeowners about how to open their panel and check for defects or repair them. We urge you to hire a licensed electrician.

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    Here’s links with answers to some Frequently Asked Questions (FAQ) about ELECTRICAL SERVICE:

• What is the minimum overhead electric service drop height/clearance to a house?

• Why is a leaning electrical service mast dangerous? 

• What is the fireman’s switch emergency disconnect requirement for residential electrical service?

• What are typical copper service entrance wire/cable sizes for the electrical service to a house? 

• What are typical aluminum service entrance wire/cable sizes for the electrical service to a house?

• What is the minimum clearance of overhead electric service drop wires above a house roof? 

• What is three phase electric service?

• What is a reliable way to tell if the electrical service is 3 phase or single phase? 

• What does it mean when I find buried yellow "CAUTION" tape when digging a hole in the yard?

• How can I find out the size of the electric service to a house?

• What is the difference between the electric service to a mobile home and a site built home? 

• What are the clearance requirements for an overhead electric service drop that is directly over or near a swimming pool?  

• What is the minimum size electric service to a mobile/manufactured home?

• Can anything else be attached to a service mast for overhead electric service besides the service cables? 

• What is the electrical "service point" of a house? 

• Why is there a 3-phase breaker in a single phase panel with only two bus bars?

• What is the difference between single-phase and three-phase electric service? 

• What is the minimum clearance under an electrical service drip loop of a house? 

     Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.