Picture the whole run: a distribution pole, a service drop crossing the yard to a weatherhead on the house, a meter on the wall, and the breaker panel just inside. Two different codebooks govern this picture, and they hand off at exactly one spot. Before you read another word, name that spot. Where does the utility’s responsibility end and the customer’s begin?
The answer is the service point. Everything from the pole down to that point is the utility’s world; everything past it is the customer’s. Get that single boundary right and the rest of code triage falls into place. Get it wrong and you will cite the wrong standard, spec the wrong equipment, and lose the room with the first engineer who notices.
The NESC, the National Electrical Safety Code, is IEEE C2, and it governs the utility side of the service point. That means the overhead and underground supply and communication lines, plus the substations that feed them. When a lineman restrings primary on a pole, sets a pad-mount transformer, or works inside a substation fence, the rules of construction, clearance, and grounding come from the NESC. It is written for the people who own and operate the grid.
The NEC, the National Electrical Code, is NFPA 70, and it governs the customer side, the premises wiring. Its jurisdiction begins at the load side of the service point and runs through the service entrance, the panel, the feeders, and every branch circuit to the last receptacle. The electrician pulling wire inside a building is working entirely under the NEC. The two codes do not overlap at the boundary; one ends where the other starts.
The service point is the defined demarcation where NESC jurisdiction hands off to NEC jurisdiction, and it is the answer to almost every “which code applies” question on a service. In practice you will most often see that handoff realized at the meter or the weatherhead, where the utility’s drop or lateral lands on the customer’s equipment. The meter is the common physical marker, but the service point is the defined boundary, not a guarantee that the meter is always the exact point. The utility’s service rules and the local jurisdiction can place it elsewhere.
One distractor trips people who are new to this. NFPA 70E is workplace electrical safety, not an installation design code. It tells a worker how to protect themselves from arc flash and shock; it does not tell anyone how to build a line or a panel. When a question asks which code governs an installation, 70E is never the answer. Neither is IEEE C57, which is the transformer standard series and covers the device, not the boundary.
This is educational material, not engineering or procurement advice; confirm any jurisdiction boundary or code citation against the current editions of the NESC (IEEE C2) and the NEC (NFPA 70), your serving utility’s service rules, and a licensed professional before you rely on it.
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