Rack PDUs and whips.
The last metre of the power path is handled daily by the least electrically trained people in the building. The standard scopes in at 50 volts — which puts every rack feed in the room on the right side of that line, and everyone touching one inside the standard's reach.
208 V is in scope. All of it.
110.2(B) applies to circuit parts operating at 50 volts or more, or wherever an electrical hazard exists. A 208 V rack whip, a 240 V busway drop, a 415 V feed to a high-density row — all of it sits above the scope line, full stop. 'It's just rack power' is not a category the standard recognises. What keeps daily rack work routine is not an exemption from scope; it is that plugging and unplugging listed connectors, used per their listing, on healthy equipment, is normal operation under Exception No. 1 — the task is operation, and the seven conditions describe the equipment state.
That framing carries a discipline with it: a scorched receptacle, a whip with damaged jacket, a connector that resists seating — any evidence of impending failure — collapses the normal-operating-condition case, and the task stops being routine at the moment the evidence appears.
The population is the hazard multiplier
Racking servers and dressing power in live rows is done overwhelmingly by unqualified persons in 70E's sense — capable technicians with no electrical safety training at all. The standard's machinery for them is blunt: keep them outside the limited approach boundary of any exposed energized parts, restrict access where a permit exists, and train the awareness tier under 110.4 so they can recognise what they are looking at. In a data hall that machinery translates to three concrete things: closed dead-fronts on every energised panel in the rows, a rule that no cover comes off while unqualified staff are in the aisle, and awareness training for IT and remote-hands staff — which is precisely the audience of the 4-hour awareness course.
An open RPP with a contractor inside it, in an aisle full of server techs, is two populations sharing one boundary — and only one of them knows it exists.
Under the floor
Whip work under a raised floor concentrates the classic conditions for contact: cramped reach, poor sight lines, live and dead circuits sharing tray, and connectors that get disconnected under load when a decommission order and a power order cross. Disconnecting under load is an interruption task, not a plug event — a listed locking connector tolerates it; the practice still belongs inside a procedure that verifies which whip, which receptacle, and whether the load is actually off first. The absence-of-voltage habit scales down: verify the whip you are about to handle is the whip on the order.
A decommission crew unplugging whips by circuit ID from a spreadsheet last reconciled two refresh cycles ago. Three whips in, the IDs and the receptacles no longer agree, and nobody on the crew is qualified to open the RPP and trace. The spreadsheet is the finding — power path records are safety documents in a building where unqualified staff execute power changes.
Power change in the rows? If the task is anything beyond plug-and-unplug on healthy gear, it left 'normal operation' — walk it.
This is the material of the 8- and 16-hour NFPA 70E classes — taught on the 2027 edition, against data center topology, about 55 times a year. Private onsite days run against your one-lines.