An operating room in a hospital has been designated a wet procedure location by the governing body of the facility. What protection does the Code require for the receptacles and the fixed equipment installed in that room?
- AGround-fault protection of equipment on the feeder, set to open at not more than 30 milliamperes
That style of protection belongs to other occupancies such as marinas. Patient safety in a wet procedure location is addressed by devices that either open at personnel protection levels or avoid opening at all.
- BTwo grounding paths to every receptacle, one being the raceway and the other an insulated conductor
Redundant grounding is required for patient care spaces generally, but it is not the answer to the wetness hazard. A wet procedure designation adds a further requirement on top of it.
- CArc-fault circuit-interrupter protection on every branch circuit entering the room, located at the panelboard
Arc-fault protection addresses ignition of building materials by arcing faults and has nothing to do with shock hazard in a wet environment.
- Ground-fault circuit-interrupter protection, or an isolated power system where power cannot be interrupted
Why D is correct
Wet procedure locations must be protected either by ground-fault circuit interrupters or by an isolated power system, and where the interruption of power itself cannot be tolerated during a procedure the isolated power system is the required choice. Isolated power does not trip the circuit; it limits fault current and annunciates the fault instead.
What this question is testing
Tests whether you know the two permitted forms of protection for a wet procedure location and the condition that forces the choice, and whether you can separate that requirement from the redundant grounding rule that applies to patient care spaces generally.
On the job
Whether a room is designated wet drives thousands of dollars of equipment, so the decision is documented in the project design and the electrician builds to it. Operating rooms, some procedure rooms and certain therapy areas are the usual candidates. Standard patient rooms and corridors are not. The line isolation monitor panel in a surgery suite is the visible sign that an isolated power system was chosen, and its alarm means a first fault has occurred while everything keeps running.
Memory technique
Where the power must not stop, isolate it instead of tripping it.
Exam tip
Wet procedure location: interrupt the circuit, or isolate it. Where interruption is intolerable, isolate.
Where to look it up
Article 517 covers health care facilities; wet procedure locations are addressed in Part II along with the patient care space grounding requirements.