NEC 250.32(B)
What it means on the job
This is correct. In a sub-panel (whether in the same building or a separate structure with a 4-wire feeder), the neutral must be isolated from the equipment grounding conductor and the enclosure. Bonding neutral to ground at a sub-panel creates parallel paths for return current, which can put current on metal parts and create shock hazards. The bonding is done only at the main panel (service equipment).
Tested in 1 CraftIQ puzzle
- code-checkGrounding at Sub-Panel
Related NEC sections
NEC 250.118 / 410.44
Suspended ceiling support wires and grid members are not listed as equipment grounding conductors. A separate equipment grounding conductor or grounding path must be provided for all lighting fixtures.
NEC 250.118(5)
Flexible metal conduit over 6 feet in length requires an equipment bonding jumper. Even under 6 feet, the FMC connections must provide a reliable ground path, and many jurisdictions require a bonding jumper regardless of length.
NEC 250.146(D) / high-rise office Electrical Plans
Data rooms require isolated ground (IG) receptacles to prevent electromagnetic interference from the building's general grounding system from affecting sensitive electronic equipment. The high-rise office plans specifically call out IG receptacles for data room locations.
NEC 250.53(D)(2)
A metal underground water pipe electrode must be supplemented by an additional grounding electrode. It cannot serve as the sole grounding electrode because plastic pipe repairs can interrupt the path.
NEC 250.64(C)
Grounding conductor splices must use listed connectors such as split bolts, compression connectors, or exothermic welds. Electrical tape alone is not a listed grounding connection method.
NEC 314.16(B)
Box fill calculations per NEC 314.16 require each #12 conductor to have 2.25 cu in. An overfilled box causes conductor damage, overheating, and difficulty making proper connections.
CraftIQ explanations are original educational commentary written in trade language and verified against the cited standards. Always confirm requirements against the code edition adopted by your jurisdiction — this is training material, not a substitute for the code book or your AHJ.