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Friday, January 20, 2023
Question:
The requirements found in Section 210.12(A) apply to ALL 120 volt, single-phase, 15- and 20-amp outlets in the specified areas. For example, in a dwelling unit bedroom the lighting outlets, receptacles outlets, smoke detector outlets, and even a baseboard heater outlet if its supply falls within the voltage and amperage parameters.
A
Answer:
Hi William, glad to hear you are enjoying the CQD. Section 250.52(A)(3) requires the use of a Concrete Encased Electrode by using one of two methods:
(1) Connting a Grounding Electrode Conductor to a conductive 1/2" steel reinforcing bar(s) 20' continuous, or multiple sections tied together.
(2) Bare copper condictor not smaller than #4 AWG.
When using either of the options given they are required to be encased in 2” of concrete and shall be located horizontally within a portion of the concrete foundation or footing that is direct contact with the earth.
There are two issues with using the slab for the concrete encased electrode. One (1) the slab is not foundation or footing level and two (2) typically the slab is floating on a layer or stone and plastic vapor barrier. This essentially insulates the slab from the earth rendering the slab ineffective as an electrode.