The year 2020 provided me with the unique opportunity and the time to produce a series of videos on topics that you told me were of interest to you. I recorded them from my house, and livestreamed them over the course of several months. There were a lot of you that might not have been able to tune in, and others who did, but would enjoy the chance to see them again. We'll be sending them out monthly in a newsletter series. Enjoy and feel free to share!
 How do you size the grounding electrode conductor? A grounding electrode conductor connects the electrical system or equipment to a conductive object that establishes a direct connection to the earth, known as a grounding electrode. There are eight types of allowable electrodes in the National Electrical Code and sizing the grounding electrode conductor may vary for a given type.
A grounding electrode conductor to an electrode is required at services [250.24(A)], at separate buildings or structures [250.32(A)], and for transformers and generators that are separately derived systems [250.30(A)(5)]. Table 250.66 for sizing grounding electrode conductors is based on the largest phase conductor or equivalent area of parallel conductors, pay close attention to 250.66(A) through (C) before taking a look at the Table 250.66.
Grounding electrode conductors that only connect to ground rods are not required to be larger than 6 AWG copper [250.66(A)] and similarly grounding electrode conductors that only connect to concrete encased electrodes (rebars) are not required to be larger than 4 AWG copper.
It’s crucial to understand that the grounding electrode conductor is not sized for the purpose of clearing faults. So then when do we use Table 250.66? For example, if the electrode type is structural steel and if there is any combination of grounding electrodes that are not solely the ground rod or concrete encased rebar.
Enjoy this “LIVE” video series covering the details on how to size grounding electrode conductors!
Click here or on the image to watch the video [14min:46sec].
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