Stumped by the Code?

Dec 1, 2006 12:00 PM, By Mike Holt, NEC Consultant

All questions and answers are based on the 2005 NEC.

Fig. 1 Hospital-grade receptacles are not required in locations such as treatment rooms of clinics, medical and dental offices, or outpatient facilities.

Q. Do I need to use hospital-grade receptacles in a chiropractor's or medical examining room?

A. No. Only receptacles for inpatient sleeping beds or procedure table beds used in a critical patient care area (patient bed location) must be listed as “hospital-grade” [517.18(B) and 517.19(B)(2)] (Fig. 1).

Q. Can I use low-voltage cable for 24V lighting supplied by a 1.5kVA transformer?

A. No. All wiring must be in accordance with Chapter 3 of the NEC, unless Chapters 5 through 8 modifies the general requirements [90.3]. Since there are no rules in Chapter 5 through 8 that modify the wiring method requirements for low-voltage lighting (over 100VA), you'll need to use a traditional wiring method, such as Type MC cable, EMT and wire, or where permitted, Type NM cable.

Fig. 2. There are exceptions that allow for the routing of normal wiring and emergency wiring in the same enclosure.

Q. Does the NEC require a building owner to have spare light bulbs and batteries for emergency lighting and exit signs?

A. No.

Q. What are the rules on mixing emergency circuits in the same raceway or enclosure with nonemergency circuits?

A. To ensure that a fault on the normal wiring circuits will not affect the performance of emergency wiring or equipment, all wiring from an emergency source, or emergency source distribution overcurrent protection device, to emergency loads must be kept entirely independent of all other wiring and equipment, except as permitted for [700.9(B)]: (1) wiring in transfer equipment enclosures (Fig. 2); (2) wiring supplied from two sources in exit or emergency luminaires; or (3) wiring from two sources in a common junction box, attached to exit or emergency luminaires.