Code Explained
What the National Electrical Code and the California Electrical Code ask for, why, and where to read it yourself.
How California Adopts the NEC (and Why Your City Can Add Rules)
The National Electrical Code isn’t law until a state adopts it. Here is how the 2023 NEC became the 2025 California Electrical Code, and where local amendments fit.
Read article →2 min readGFCI and AFCI: What They Do and Where the 2023 NEC Wants Them
GFCIs protect people from shock. AFCIs protect homes from arcing fires. Here is how each one works and where the 2023 NEC (2025 CEC in California) calls for them in homes.
Read article →2 min readWhole-Home Surge Protection and NEC 230.67
Since the 2020 NEC, new and replaced dwelling services need a surge protective device. Here is what it does, what changed in 2023, and what it doesn’t do.
Read article →2 min readLoad Calculations: Does Your Panel Have Room? (NEC Article 220)
Before adding a heat pump, EV charger or shop, we check whether the service can handle it. Article 220 gives the methods, including one that uses a year of real meter data.
Read article →2 min readGrounding vs Bonding: What Article 250 Is Really Doing
Grounding and bonding are two different jobs that people often mix up. One connects to the earth; the other gives fault current a fast path home so the breaker trips.
Read article →2 min readWorking Space Around Panels (NEC 110.26)
Why we ask you not to put shelves, water heaters or the freezer in front of your electrical panel, with the depth, width and height the code calls for.
Read article →12 min readShared Neutrals and Multiwire Branch Circuits (NEC 210.4)
Two or three circuits sharing one neutral is normal and legal, until the hots land on the same leg, a breaker gets turned off for "just one circuit", or AFCI and GFCI breakers start tripping. How shared neutrals work at home and in commercial buildings, the code rules, and the field facts that catch people.
Read article →Local rules decide. These articles explain general ideas and point to the code sections we use. They are not legal or engineering advice and don’t replace the code itself. California adopts the NEC with its own amendments, cities and counties can add more, and the local inspector (the AHJ, or authority having jurisdiction) has the final say on any job. Read the code free at NFPA’s free access page.