Stumped by the Code?
All questions and answers are based on the 2008 NEC.
Q. I have a 1,200A, 480V panel that has a working space of 3½ feet. The engineer says 7 feet is required. Is he correct?
A. Maybe. The working space, which is measured from the enclosure front, must not be less than the distances contained in Table 110.26(A)(1). If you have grounded metal parts on the other side of the working space, you would need 3½ feet. If you have equipment 1,200A or greater, more than 6 feet wide, you also must have an entrance to/egress from the working space at each end of the working space [110.26(C)(2)]. If you have double the required work space (7 feet in this instance) a single entrance/egress is allowed, if it is located at least the required working space distance(3½ feet) from the equipment [110.26(C)(2)(b)] (see Figure).
Q. What do I do with the little bare aluminum wire in hospital-grade AC cable?
A. The internal aluminum bonding strip within the cable serves no electrical purpose once it is outside the cable; therefore, it can be cut off. However, many electricians use it to secure the anti-short bushing to the cable.
Q. Does a motor disconnect require a 3-foot working space?
A. Equipment that may need examination, adjustment, servicing, or maintenance while energized must have sufficient working space in accordance with Table 110.26(A)(1). The phrase “while energized” is at the root of many debates. So, as always, check with the authority having jurisdiction (AHJ) to see what equipment he/she believes needs a clear working space.
Q. Is GFCI protection required for receptacles located in a walk-in freezer of a restaurant?
A. All 15A and 20A, 125V receptacles installed in an area with a sink and permanent facilities for food preparation and cooking [Art. 100], even those that don't supply the countertop surface, must be GFCI protected [210.8(B)(2)]. Many people would say that a walk-in freezer is not part of the kitchen “area,” but it is best to check with the AHJ.
Q. Do we have to add GFCI receptacles in our facility each time the Code changes and requires more of them?
A. No, the NEC is an installation standard, not a maintenance standard. However, when existing receptacles are replaced in locations where GFCI protection is currently required, the replacement receptacles must be GFCI protected [406.3(D)(2)].
Q. Do the conduit fill requirements apply to a raceway containing telephone wires?
A. No. See requirements in 800.110.
Q. Where in the NEC does it indicate how far away from a bathtub or shower a switch needs to be located?
A. Switches can be located next to (but not within) a bathtub, hydromassage bathtub, or shower space [404.4, 680.70, and 680.72].