For those of us that employ NFPA 70, National Electrical Code (NEC) on a regular basis we understand the importance the NEC plays when it comes to the installation of safe electrical systems. In the early pages of the standard its purpose is clearly stated as the practical safeguarding of persons and property from hazards arising from the use of electricity. The purpose of the NEC could never be accomplished without the proper application of Article 250 – Grounding and Bonding.
While all of Article 250 is crucial to a safe installation, many installation errors evolve from incorrectly using the tables that size grounding electrode conductors, bonding jumpers, and equipment grounding conductors. Whether you are an engineer designing the job, and electrician doing the installation, or an inspector verifying a correct installation, applying these tables in Article 250 is paramount to ensuring the safety of both persons and property.
To help workers understand the crucial role these tables hold in a safe electrical system, NFPA created a new fact sheet that walks you through the proper application of the following tables within Article 250:
- Table 250.66 - Grounding Electrode Conductor for Alternating-Current Systems
- Table 250.102(C)(1) - Grounding Conductor, Main Bonding Jumper, and Supply-Side Bonding Jumper for Alternating-Current Systems
- Table 250.122 – Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment
For more information on grounding and bonding within Article 250, join us on the NEC Facebook page this Friday, July 17th at 3:30PM EST as the NEC goes live (#NECLive) to discuss: The Top 10 Grounding and Bonding Questions. Additional information about grounding and bonding is available on our website.
For more information related to the NEC, please visit NFPA’s electrical solutions webpage.