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Verifying that the grounding conductor is correctly sized.

Question asked by mberzoza on Feb 4, 2019
Latest reply on Feb 4, 2019 by mberzoza

To whom it may concern,


Good morning from Texas, I would like to verify a decision that I have made with you all. Before I go into detail, allow me to give a brief overview of what I am trying to do. I have been tasked to verify and implement, where needed, grounding connections. I have chosen to start with Motors and would like for you to please confirm my decision.


By reading the National Electrical Code (NEC) 70E Article 430.245 and Part VI Article 250.110(4), it was deemed necessary to have the motor connected to a grounding conductor. The size of said conductor I have gotten from Table 250.122 of (NEC) 70E.


Here is where I would like to be double checked, I have a motor that has a nameplate rating of 1,150 amps, and according to Table 250.122 as well as the corresponding note below the table, please see attached, am I correct that I should use a Copper 3/0 wire to ground the motor.


Thank you for your time.