NEC 250.118 / 410.44

NEC 240.86 / high-rise office Specification

The high-rise commercial office specification explicitly prohibits series rating of overcurrent protective devices. All existing panels being re-utilized must use fully rated breakers — meaning each individual breaker must have an interrupting rating equal to or exceeding the available fault current at the panel (22kAIC in this case). Series rating is prohibited because in a multi-tenant high-rise, a fault that exceeds a branch breaker's interrupting rating could cause catastrophic breaker failure, arc flash, and damage to adjacent tenants' electrical systems. The branch breaker must be replaced with one rated at minimum 22kAIC.

NEC 250.102

Flexible metal conduit in this size/length is not a reliable ground path; an equipment bonding jumper or an EGC must be run to bond the motor.

NEC 250.118 / 250.122 / 406.4(C)

Even though UF cable includes a grounding conductor, if individual conductors are run in conduit underground, an equipment grounding conductor of a recognized type must be included and sized with the circuit so the receptacle has an effective ground-fault current path.

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 250.32(B)

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).