Click Here to Receive DIY Electrical Wiring Help from a Master Electrician
 


Top

Connecting The Grounding Electrode Conductor To Rebar

November 30, 2005

Q: Where reinforcing steel in a concrete slab that is in contact with the earth is used as a grounding electrode, may the grounding electrode conductor be clamped to a rebar within the concrete or must the connection be made on the outside of the concrete?

A: Generally, the connection of the grounding electrode conductor to the grounding electrode must be accessible. However, 250.68(A) has an exception to this requirement. “Exception – An encased or buried connection to a concrete encased, driven or buried grounding electrode shall not be required to be accessible.”

When the connection will be encased in concrete, an inspection should be made before concrete is poured, and the ground clamp must be marked to indicate that it is suitable for direct burial. A clamp that is suitable for concrete encasement is amrked “direct burial” or “DB.” I would recommend exothermic welding.

Normal practice is to have the general contractor turn up 6 to 12 inches of reinforcing steel rod on both sides of the proposed building if the location of the service is unknown to permit the electrical contractor to connect the grounding electrode conductor to the rebar when electricians arrive at the construction site.

Get the Tools and Guidance You Need to SAFELY and Successfully Complete ALL of Your “Do-It-Yourself” Home Wiring & Installation Projects from a Master Electrician with Over 20 Years Experience by visiting www.gilchrist-electric.com today.

Are Recessed Cans Installed Above Bathtubs Required To Be GFCI Protected?

November 28, 2005

Q: Are recessed lighting fixtures installed in the ceiling above a bathtub in a dwelling unit required to be protected by a ground fault circuit interrupter (GFCI)? The recessed cans are marked “Suitable for Damp Locations.”

A: The recessed cans are not required to be GFCI protected to comply with the NEC. GFCI protection in dwelling units applies only to 15- and 20-ampere , 125-volt receptacles. However, you must read your installation instructions; some manufacturers require GFCI protection in damp locations for their fixtures. If this is the case with your fixtures, GFCI protection must be provided to comply with 110.3(B); which states “Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.”

Get the Tools and Guidance You Need to SAFELY and Successfully Complete ALL of Your “Do-It-Yourself” Home Wiring & Installation Projects from a Master Electrician with Over 20 Years Experience by visiting www.gilchrist-electric.com today.

Water Heater Overcurrent Protection

November 27, 2005

Q: What is the minimum and maximum breaker size for an electric water heater? What is the minimum wire size for a 4,500 watt, 240 volt single-phase water heater?

A: Let’s calculate the minimum ampacity of the branch circuit conductors first. 422.13 states “Storage-Type Water Heaters. A branch circuit supplying a fixed storage-type water heater that has a capacity of 120 gallons (450 L) or less shall have a rating not less than 125 percent of the nameplate rating of the water heater.” (4,500 divided by 240 x 1.25 = 23.4 amps) This means you must use 10 AWG copper conductors.

The minimum size overcurrent protection for this water heater is 25 amperes. This is the next standard size circuit breaker, according to 240.6. Even though the NEC says this is a standard size, no one stocks this size.

If the water heater nameplate does not list a maximum size overcurrent device, 422.11(E) states “If the overcurrent protection rating is not marked and the appliance is rated over 13.3 amperes, not to exceed 150 percent of the appliance rated current. Where 150 percent of the appliance rating does not correspond to a standard overcurrent device ampere rating, the next higher standard rating shall be permitted.” (4,500 divided by 240 x 1.5 = 28 amperes) The next standard size circuit breaker is 30 amperes, according to 240.6.

 

Does A Wall Switch In A Bedroom, That Controls Outside Lights, Have To Be AFCI Protected?

November 26, 2005

Q: Does an arc-fault circuit-interrupter protected circuit have to be provided for a wall switch in a one-family-dwelling master bedroom that supplies outdoor lighting? The switch does not control any loads in the bedroom. What about a junction box that contains only splices? The branch circuit that supplies power to the box does not supply any load in the bedroom.

A: The answer is no to both questions.

Article 210.12 (B) states “All branch circuits that supply 125-volt, single phase, 15- and 20-ampere outlets installed in dwelling unit bedrooms shall be protected by an arc-fault circuit interrupter listed to provide protection of the entire branch circuit.”

A switch or a junction box is not an outlet.

Article 100 defines an outlet as ” a point on the wiring system at which current is taken to supply utilization equipment.”

Get the Tools and Guidance You Need to SAFELY and Successfully Complete ALL of Your “Do-It-Yourself” Home Wiring & Installation Projects from a Master Electrician with Over 20 Years Experience by visiting www.gilchrist-electric.com today.

How many receptacle outlets are required in a large Foyer of a home?

November 25, 2005

Q: Does the National Electrical Code require the installation of receptacles outlets in the walls of a large foyer in a single family home?

A: Foyers are not metioned in the NEC. However article 210.52(A) states “In every kitchen, family room, dining room, living room, parlor, library, den, sun room, bedroom, recreation room, or similar room or area of dwelling units, receptacle outlets shall be installed in accordance with the general provisions specified in 210.52 (A)(1) through (A)(3).”

Webster’s dictionary defines a foyer as an entrance hall. Article 210.52 (H) states “In dwelling units, hallways of 10 feet (3 m) or more in length shall have at least one receptacle outlet. As used in this subsection, the hall length shall be considered the length along the centerline of the hall without passing through a doorway.”

If your foyer has an unbroken wall length (no doors or openings) of 10′ (3 m) or longer, you are required to install at least one receptacle outlet.

We always install at least one receptacle outlet in all of the foyers of homes that we wire. We have learned that most homeowners place a table with a lamp in the foyer. This is also a great place to plug in a vacuum cleaner or floor polishing appliance.

Get the Tools and Guidance You Need to SAFELY and Successfully Complete ALL of Your “Do-It-Yourself” Home Wiring & Installation Projects from a Master Electrician with Over 20 Years Experience by visiting www.gilchrist-electric.com today.

Next Page »

Bottom