230.7 Other Conductors.

Service conductors are NOT permitted to be installed in the same underground box as non-service conductors.
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Service conductors are NOT permitted to be installed in the same underground box as non-service conductors.

Code Change Summary: Revised code language on separating service conductors from other than service conductors.

For years Section 230.7 has prohibited service conductors from being in the same raceway or cable as non-service conductors. The intent is to limit situations where unprotected service conductors are in close contact with other conductors. An insulation failure could potentially supply the non-service conductors with way more current than they are rated for.

Section 230.7 does not prohibit service conductors and non-service conductors from occupying the same gutter space of a service panelboard cabinet.

In the 2023 NEC®, Section 230.7 has been expanded to prohibit service conductors from being installed with non-service conductors in the same raceway, cable, handhole enclosure, or underground box.

One would hope that even if the NEC® was silent on this that a good electrician would understand the intent of the code and avoid doing something like this whether or not code language specifically mentioned it.

Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC® edition of NFPA 70.

2020 Code Language:

230.7 Other Conductors in Raceway or Cable. Conductors other than service conductors shall not be installed in the same service raceway or service cable in which the service conductors are installed.

2023 Code Language:

230.7 Other Conductors. Circuit conductors other than service conductors, shall not be installed in the same raceway, cable, handhole enclosure, or underground box as the service conductors.

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230.7 Other Conductors.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Based on the 2023 NEC, which of the following is true in Section 230.7?

A: Service conductors and non-service conductors are permitted in the same underground box.
B: Service conductors and non-service conductors are permitted in the same cable.
C: Service conductors and non-service conductors are permitted in the same raceway.
D: Section 230.7 has been expanded to prohibit service conductors from being installed with non-service conductors in the same raceway, cable, handhole enclosure, or underground box.
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