Health Care Facilities practice questions

Correct: C — At least two branch circuits, one from the normal system and one from the critical branch

517.18(A) requires at least two branch circuits at each Cat 2 bed location: one from the normal system and one from the critical branch. A single critical-only circuit or a multiwire circuit does not satisfy this, and three circuits across all three branches is not the stated minimum.

Correct: A — Eight

517.18(B)(1) sets the minimum at eight receptacles per Category 2 patient bed location. Four, six, and ten are not the code-specified minimum.

Correct: C — Task illumination only, with receptacles omitted

517.34(A)(2)(a) lists psychiatric bed areas among patient care spaces needing task illumination and select receptacles, but explicitly says receptacles are omitted for psychiatric bed areas. The 'same as other patient care spaces' choice ignores that carve-out; the other two options misstate that illumination is required at all.

Correct: C — Three — life safety, critical, and equipment

517.31(A) requires exactly three branches — life safety, critical, and equipment — regardless of how many transfer switches are used. Optional loads are not a fourth branch; they're loads not specifically named in the article, handled separately under 517.31(B)(1). Branch count is not tied to switch count.

Correct: B — When the enclosure is transfer equipment, or supplies exit/emergency luminaires fed from two sources

517.31(C)(1)(b) permits sharing only in transfer equipment enclosures, dual-source exit/emergency luminaires or their common junction box, or circuits fed from the same branch and same transfer switch. A barrier inside a shared raceway, an amperage threshold, and mere equipment-branch membership are not listed exceptions.

Correct: D — Class I, Division 1 up to 5 ft above the floor, with the space above considered above a classified location

Per 517.60(A)(1), a use location for flammable anesthetics is Class I, Division 1 only up to 5 ft (1.52 m) above the floor; the remaining volume to the ceiling is above the classified space, not part of it. The floor-to-ceiling option applies to storage locations under 517.60(A)(2), not use locations, and Division 2 and unclassified are both wrong since flammable anesthetic use always creates a Division 1 area.

Correct: D — At least two branch circuits, one or more from the critical branch and one or more from the normal system

517.19(A) requires at least two branch circuits per patient bed location, with at least one from the normal system and at least one from the critical branch. Using only the critical branch, or two critical circuits without a normal circuit, does not meet this dual-source requirement.

Correct: A — On the normal system branch circuit from 517.19(A)(2), or a critical branch circuit fed by a different transfer switch than the other bed receptacles

517.19(B)(1) requires at least one receptacle to be on the normal branch circuit required by 517.19(A)(2), or on a critical branch circuit supplied by a different transfer switch than the rest of the bed's receptacles. Feeding it from the same transfer switch as the others defeats the redundancy the rule is designed for, and isolated power systems and GFCI-only circuits aren't what this section requires.

Correct: B — It is never required — it's an optional additional protective technique

517.19(F) lists isolated power systems as something "permitted to be used" for Category 1 spaces — an optional additional protective technique, not a mandatory one. The anesthetizing-location and patient-care-equipment options describe other NEC scenarios, not a requirement triggered here.

Correct: C — 36, divided between at least two branch circuits

517.19(C)(1) requires a minimum of 36 receptacles per operating room, divided between at least two branch circuits. The 24 and 12 figures are the upper and lower bounds of a different subset — the receptacles tied to the normal or critical branch circuit — not the room's total minimum.

Correct: B — Enough to meet the maximum actual demand likely to be produced by the connected load

517.31(D) requires the essential electrical system to have capacity and rating to meet the maximum actual demand likely produced by the connected load. It doesn't mandate a flat 125% margin, full connected load with no demand factors, or matching the normal service — those describe unrelated sizing approaches.

Correct: A — Longer than 0.1 second

517.31(G) sets the threshold at fault durations extending beyond 0.1 second. Some candidates confuse this with the 1-second threshold used elsewhere in coordination discussions, or assume coordination applies universally, but the section also states two specific exceptions exist.

Correct: A — A connection point for a portable diesel generator

517.30(B)(3)(e) requires a connection for a portable diesel generator where life safety and critical portions of the distribution system are present. The code does not mandate a duplicate fuel cell system or a specifically 24-hour battery system for this purpose.

Correct: C — An additional step of ground-fault protection using overcurrent devices and current transformers to open that disconnect

517.17(B) requires an additional step of ground-fault protection at the next level feeder disconnecting means downstream whenever GFPE is provided at the service or feeder disconnect per 230.95 or 215.10. Assuming the service-level protection is sufficient ignores this added requirement, a surge protective device is an unrelated device, and the rule is not limited to feeders serving Category 2 spaces.

Correct: B — Within the patient care vicinity

517.16(A) prohibits isolated ground receptacles specifically within the patient care vicinity. Outside that vicinity, patient care spaces may still have them if wired per 517.16(B)(1) and (B)(2), so the blanket 'anywhere in a patient care space' option is too broad.

Correct: C — 1 mA

Per 517.160(B)(2), the line isolation monitor must have enough internal impedance that the maximum current it draws under a ground fault condition is 1 mA. 5 mA is a common GFCI-adjacent threshold from other contexts, not this rule; 2 mA and 0.1 mA are not the specified limit.

Correct: B — A waiting room in a medical office

517.10(B)(1) excludes business offices, corridors, and waiting rooms in clinics, medical and dental offices, and outpatient facilities. Operating rooms, recovery rooms, and general treatment/examination rooms are patient care spaces covered by Part II under 517.10(A).

Correct: C — Life safety, critical, and equipment branches

517.29 defines a Type 1 essential electrical system as comprised of three separate branches: life safety, critical, and equipment. The other options mix in terms like 'normal,' 'standby,' or 'feeder' that aren't the defined branch names under this section.

Correct: A — Restore its equipment automatically at appropriate time-lag intervals

517.44 requires the equipment branch to be installed so listed equipment is automatically restored at appropriate time-lag intervals following energizing of the life safety and critical branches — not instantaneously, and not by manual action.

Correct: A — 10 seconds

517.43 requires life safety branch functions to be automatically restored to operation within 10 seconds of a normal source interruption. The 60-second and 10-minute options confuse this with longer delayed-automatic timing used elsewhere in essential electrical systems, and 4 seconds is faster than the code requires.

Correct: D — It qualifies as an equipment grounding conductor per 250.118

Per 517.61(C)(1), the metal raceway system or cable armor/sheath assembly must itself qualify as an equipment grounding conductor under 250.118. Hazardous-location listing and wet-location listing aren't the requirement here, and a separate insulated grounding conductor isn't what makes the raceway/cable acceptable — the metal enclosure itself must serve as the grounding path.

Correct: C — It continues to operate through a single line-to-ground fault, inherently limiting the fault current to a low value.

517.20(A) requires isolated power systems to remain in operation through a first line-to-ground fault while inherently limiting the fault current to a low value. The GFCI-trip behavior belongs to the other permitted method, the therapeutic/diagnostic allowance is a separate exception for grounded services, and AFCIs play no role in either 517.20(A) protection method.

Correct: D — They must be listed for hospital use, 2-pole, 3-wire grounding type

517.61(B)(5) requires receptacles and attachment plugs above hazardous anesthetizing locations to be listed for hospital use and, for 120-volt single-phase service, to be of the 2-pole, 3-wire grounding type with provision for the equipment grounding conductor. A non-grounding device does not meet this requirement, and the section calls for hospital-grade listing, not GFCI protection or isolated-ground construction.

Correct: C — Standard Type MC cable without a continuous gas/vaportight sheath

517.61(B)(1) permits RMC, EMT, IMC, Type MI cable, or Type MC cable, but only if the Type MC cable has a continuous, gas/vaportight metal sheath. Ordinary Type MC cable without that sheath doesn't qualify.

Correct: D — 10 seconds

517.32(B) requires life safety and critical branch functions in a Type 2 EES to be automatically restored within 10 seconds of a normal source interruption. The 60-second and 150-second options are longer restoration windows used elsewhere for other equipment branches, not the life safety/critical branch requirement here, and 4 seconds is shorter than the code specifies.

Correct: C — They may be switched like normal lighting

517.34(B) permits control (switching) of task illumination on the critical branch. There's no requirement that it stay permanently energized, be switched only at the transfer switch, or use automatic timing only.

Correct: C — To prevent a single event from interrupting both sources simultaneously

517.30(C)(2) requires physical separation of the alternate source feeders from the normal source feeders specifically to prevent possible simultaneous interruption of both. Voltage drop, conduit fill, and working clearances are real NEC concerns elsewhere but are not the reason for this separation requirement.

Correct: A — Article 700, Emergency Systems

517.26 states the life safety branch shall meet the requirements of Article 700, except as amended. Articles 701, 702, and 708 are related but distinct standby/emergency power articles not referenced by 517.26.

Correct: C — Two or more independent sources

517.30(A) requires the EES to have two or more independent sources (or sets of sources). A single source, even on-site, does not satisfy the redundancy requirement.

Correct: D — The feeder GFPE opens and the service GFPE remains closed

517.17(C) requires full selectivity: the feeder device opens on a load-side fault while the service device stays closed. Tripping both devices, tripping the service first, or requiring manual isolation would all defeat the selectivity requirement and needlessly de-energize unaffected areas.

Correct: D — All conductive surfaces of the equipment are connected to an equipment grounding conductor

517.63(B)(2) requires all conductive surfaces of the equipment to be connected to an equipment grounding conductor. The isolated-power-system option is the alternative this rule lets you avoid, sharing a raceway with isolated wiring is explicitly prohibited by 517.63(B)(1), and the height requirement is a minimum of 2.5 m, not a maximum.

Correct: C — Luminaires are located at least 2.5 m (8 ft) above the floor

517.63(C)(1) requires luminaires to be mounted at least 2.5 m (8 ft) above the floor as one of the four conditions for using a normal grounded circuit. Wet-location rating, GFCI protection, and a 20 A limit are not among the conditions listed in this section.

Correct: D — Class I, Group C

517.61(A)(5) requires receptacles and attachment plugs in the hazardous location to be listed for Class I, Group C. Group D is a different (less restrictive) gas group and doesn't satisfy this rule; Class II covers combustible dust, not anesthetic vapors; and the listing requirement isn't conditioned on mounting height.

Correct: B — 517.61(A)(4)

517.61(A)(4) states that when a box, fitting, or enclosure is only partially within a hazardous (classified) location, the entire box, fitting, or enclosure is considered to be within that location. 517.61(A)(3) instead sets equipment requirements for devices operating above 10 volts, and 517.60(A)(1) just defines what makes a space a use location, neither of which addresses a boundary-straddling enclosure.

Correct: C — Not less than 50 percent of the momentary rating or 100 percent of the long-time rating, whichever is greater

517.73(A) sets the branch-circuit minimum at whichever is greater: 50 percent of the momentary rating or 100 percent of the long-time rating. Sizing at 100 percent of momentary rating or applying a 125 percent continuous-load-style factor to the long-time rating are not the rule this section states; 80 percent of momentary rating is also not the threshold given.

Correct: B — 18 AWG or 16 AWG fixture wire per 724.49

517.74(B) permits 18 AWG or 16 AWG fixture wire sized per 724.49. The 14 AWG and 12 AWG options are general branch-circuit minimums that don't apply to this control-circuit exception, and 22 AWG is smaller than the Code actually allows here.

Correct: B — 517.71(A)

517.71(A) covers fixed and stationary diagnostic imaging equipment and specifically permits a cord-and-plug connection when the branch circuit is rated 30 amperes or less. 517.71(B) instead addresses portable/mobile/transportable equipment and circuit requirements up to 60 amperes, not the wiring method for fixed units.

Correct: B — 517.78(C)

517.78(C) specifically requires non-current-carrying metal parts of diagnostic imaging equipment (controls, tables, transformer tanks, shielded cables) to be grounded per Part VII of Article 250 as modified by 517.13(A) and (B). 517.78(A) instead covers mounting of high-voltage parts within grounded enclosures, not the grounding connection method for non-current-carrying metal parts.

Correct: C — Connect the box and receptacle(s) to the equipment grounding conductor

Per 517.13(B)(1), for other than isolated ground receptacles, an insulated equipment bonding jumper that directly connects to the equipment grounding conductor is permitted to connect the box and receptacle(s) to that conductor. It doesn't replace the required green EGC, doesn't apply to isolated ground receptacles (which follow 517.16), and faceplates ground via their metal mounting screws, not a bonding jumper.

Correct: B — It must be ungrounded, with an approved overcurrent device in each conductor

517.160(A)(2) requires all circuits supplied from an isolating transformer's secondary to be ungrounded and to have an approved overcurrent device in each conductor. Solid grounding defeats the purpose of an isolated power system, and protecting only one conductor doesn't satisfy the each-conductor requirement.

Correct: D — Brown with at least one distinctive colored stripe other than white, green, or gray

Per 517.160(A)(5), Isolated Conductor No. 2 must be brown with at least one distinctive colored stripe other than white, green, or gray. The orange-with-stripe scheme is Conductor No. 1, and a stripe of white is specifically prohibited since white is reserved for grounded conductors.

Correct: C — Fire alarm systems

517.33(C)(1) requires fire alarm systems on the life safety branch with no alternative. Other alarm and alerting systems, under 517.33(C)(2), may go on either the life safety branch or the critical branch. Nurse call systems are essential electrical system loads that don't fall under this life safety branch mandate.

Correct: C — Only one of the two circuits can be selected at a time, and both can never be extinguished together

517.33(A) permits switching patient corridor lighting between general and night illumination circuits only if a single selection is enforced and both circuits can never be extinguished at the same time. Allowing simultaneous shutoff would leave the corridor dark, defeating the egress illumination requirement.

Correct: A — Task illumination at the generator set location

517.33(E)(1) requires task illumination at the generator set location on the life safety branch. The rule specifies only select receptacles, not general-purpose receptacles throughout the room, and does not extend to building HVAC or normal-power yard lighting.

Correct: B — Whether the load appears among the functions listed in 517.33(A) through (H)

517.33 makes the list in (A) through (H) the only test — a load either matches one of those enumerated functions or it cannot connect. Approval by staff, a current threshold, or sharing a transfer switch with critical care equipment are not the standard the section sets; those are all plausible-sounding but incorrect substitutes for the closed list.

Correct: B — 5 mA

517.160(B)(1) sets the standard alarm threshold at 5 mA total hazard current. The 3.7 mA figure is the minimum fault hazard current floor below which the monitor must never alarm, not the alarm-trigger point. '50% of rated capacity' misapplies the reduced-threshold provision for lower-threshold designs to a standard system.

Correct: A — An individual portable isolating transformer connected by cord and attachment plug

517.64(B)(1) permits an individual portable isolating transformer connected via cord and attachment plug, but explicitly states autotransformers shall not be used — ruling out every autotransformer-based option regardless of grounding or location.

Correct: C — An insulated continuous copper conductor not smaller than 10 AWG

517.14 requires an insulated continuous copper conductor, minimum 10 AWG, connecting the EG terminal buses of normal and essential panelboards serving the same patient care vicinity. This is a fixed minimum size, not one derived from Table 250.122, and it is required even though each panelboard already has its own equipment grounding path.

Correct: A — A Class 2 circuit that transmits power and data to a powered device

517.80 exempts Class 2 and Class 3 signaling and communications systems, Class 2 circuits that transmit power and data to a powered device, and power-limited fire alarm systems from 517.13 grounding requirements. Branch circuits, fixed lighting wiring, and essential electrical system feeders are all part of the electrical distribution system that 517.13 grounding requirements govern.

Correct: B — Permitted, but optional

517.19(D) states a patient care vicinity 'shall be permitted to have' a patient equipment grounding point — it's optional equipment, not a mandatory installation. The 'required everywhere' and 'required only in critical care' choices misstate this as mandatory, and there's no prohibition requiring special approval.

Correct: B — The metal raceway or metallic cable armor/sheath itself qualifies as an equipment grounding conductor under 250.118

517.13(A) requires the metal raceway system or metallic cable armor/sheath assembly itself to qualify as an equipment grounding conductor per 250.118, giving a redundant fault-current path. A separate insulated wire-type EGC alone doesn't satisfy this since it doesn't make the raceway or cable jacket itself the grounding path. Nonmetallic conduit with a separate ground wire fails the metal raceway/cable requirement entirely, and GFCI protection addresses shock hazard, not the grounding path redundancy this section requires.

Correct: B — Automatically, at appropriate time-lag intervals, after the life safety and critical branches are energized

517.35 requires the equipment branch to automatically restore the loads in 517.35(A) at appropriate time-lag intervals following energizing of the life safety and critical branches — not simultaneously, not manually, and not ahead of the critical branch.