Industrial Grounding Requirements You Didn’t Know Existed


Grounding is a critical aspect of any industrial electrical system. Proper grounding provides a safe path for fault currents to flow, ensures electrical noise is safely dissipated, and provides personnel protection. However, many electrical engineers and technicians are unaware of some key grounding requirements outlined in the National Electrical Code (NEC) and by organizations like IEEE. In this article, I'll cover several important industrial grounding requirements and best practices you may not know about. Adhering to these guidelines will help ensure your facility's electrical system is safe, reliable, and code-compliant.

Equipment Grounding Conductor Sizing

The NEC provides specific rules for sizing equipment grounding conductors in industrial applications. Here are some key takeaways:

Properly sizing grounding conductors is critical to ensure faults safely clear. Oversizing may be needed for large inductive loads. Consult NEC Article 250 for complete grounding conductor sizing requirements.

Grounding Electrode System

Industrial facilities require a grounding electrode system consisting of one or more grounding electrodes permanently connected to earth. This provides a low impedance path for faults and electrical noise. Here are some key grounding electrode requirements per NEC Article 250:

Properly installing multiple, redundant grounding electrodes ensures a low ground potential rise during faults. This is critical for personnel safety and protecting sensitive equipment.

Equipment Bonding and Grounding

In industrial settings, all exposed non-current carrying metal equipment must be bonded and grounded. This includes:

Proper bonding equalizes potentials and provides a low impedance path for faults. Use suitably sized bonding conductors per NEC Article 250 and common industry best practices.

Special Situations

Certain equipment requires special grounding consideration:

Consult manufacturers' recommendations and design guides like IEEE 142 for grounding these types of systems. Specialized grounding methods are often needed.


Grounding and bonding are complex but critical aspects of industrial electrical installations. This article reviewed several key grounding requirements related to conductors, electrodes, equipment, and special situations that you may not have been aware of. Following NEC guidelines, IEEE standards, and manufacturers' recommendations for your specific equipment will ensure a code-compliant, safe grounding system. Consult with an electrical engineer if you have any questions. Proper grounding is well worth the effort and prevents countless issues down the road.