NEC Questions Based on the 2008 NEC

January

 

Here is the follow up to yesterday’s newsletter. This includes all of the answers to the questions sent yesterday so you can see how you did.

 

By Mike Holt for EC&M Magazine

 

Q1. What are the termination requirements where NM Cables enter a panel?

A1. All cables must be secured to the enclosure with fittings designed and listed for the cable [312.5(C)].

 

Q2. The code uses the term “readily accessible” in a few areas, but I don’t know what that means. Please help.

A2. Article 100 defines readily accessible (accessible, readily) as capable of being reached quickly without having to climb over or remove obstacles or resort to portable ladders.

 

Q3. For a townhouse situation, can we run the feeder circuits for one unit through the attic of the neighboring units?

A3. The NEC doesn’t prohibit this, but there may be local rules (such as real estate law) that prohibit the practice.

 

Q4. Would receptacles installed in a boathouse require in-use covers?

A4. Only receptacles installed in a wet location require in-use covers [406.8]. Article 100 defines a damp location as locations protected from weather and not subject to saturation with water or other liquids, as well as locations partially protected under canopies. A boathouse is probably a damp location, not a wet location.

 

Q5.Does the code require GFCI type receptacles anywhere, or can you use GFCI breakers for all required GFCI locations?

A5. The only place the NEC requires GFCI protection of the receptacle type is for elevator pits, hoistways, elevator car tops, or escalator and moving walk wellways [680.85].

 

Q6. Does the NEC require a specific “color code” for switch legs and travelers?

A6. No.

 

Q7. What are the AFCI protection for dwelling units and what about smoke alarms?

A7. All 15A or 20A, 120V branch circuits in dwelling units supplying outlets (including smoke alarms) in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas must be protected by a listed AFCI device of the combination type [210.12(B)].

 

Q8. For a 400A service, what size wire do I need to run for my ground rod?

A8. The grounding electrode conductor that is the sole connection to the ground rod is never required to be larger than 6 AWG copper [250.66(A)].

 

Q9. What is the minimum height that a panel can be installed?

A9. There is no minimum, other than for mobile homes, which is two feet [550.32(F)].

 

Q10. Can we install a panel in the same room as an air handler and a water heater?

A10. Sure, assuming that all clearances required by 110.26 are complied with.

 

Q11. When does the code require plastic bushings over raceway fittings?

A11. Where raceways contain insulated conductors 4 AWG and larger that enter an enclosure, the conductors must be protected from abrasion during and after installation by a fitting that provides a smooth, rounded insulating surface, such as an insulating bushing  [300.4(G)]. Where IMC or RMC conduit enters an enclosure without a connector, a bushing must be provided, regardless of the conductor size [342.46 and 344.46].

 

Q12. Can I have low voltage lighting for the stairs next to my hot tub? The lights would be about three feet from the water’s edge.

A12. No, low-voltage lighting systems must not be installed less than 10 ft from the edge of the water [411.4(B)].

 

Q13. Does hard-wired equipment in a commercial kitchen require GFCI protection?

A13. No, only 15A and 20A, 125V receptacles in the kitchen must be GFCI protected [210.8(B)(2)].