Why we are Grounding? How do we know that we’re doing it the correct way? When we connect an Electrical System (Source of Voltage) to Earth through the Grounding Electrodes (Grounding Electrode System), we are Grounding. There are 2?? reasons why we do so.
The 1??st, to limit voltage induced by lightning, line surges or unintentional contact by higher voltage lines per 250.4(A)(1).
The 2??nd, to reduce voltage induced from lighting on metal parts of equipment & to reduce arcing within building or structure for Grounded Systems per 250.4(A)(2) & Ungrounded Systems per 250.4(B)(1).
Why we are Bonding?
The 1??st, to establish a low impedance ground-fault current path back to the (Supply Source) to clear a fault in accordance with 250.4(B)(5) on metal parts of raceways, cables, enclosures, equipment per 250.4(B)(3) & electrically conductive parts that can become energized such as water pipes, gas pipes & structural steel per 250.4(B)(4).
Know the difference between grounding and bonding!
The 2??nd, to minimize potential voltage differences between conductive metal parts so that all metal parts will be essentially at the same potential (no voltage difference). This is extremely important for the equipotential bonding grid for swimming pools in Article 680 & equipotential plane for agricultural buildings in Article 547
We understand that all of this is very complex.
Most importantly, electricians get it wrong all the time because of the complex nature of the 2 separate systems. They both serve very distinct purposes. Finally for us there are code experts that explain this to us and allow us to share that info just for you to help everybody understand the difference!
There are clear right and wrong ways of doing both. getting them wrong can be very dangerous Let our National Electrical Code expert team show you the difference!
Source:”Grounding vs Bonding”, March 17, 2020, Author: David Harsche