What is a Good Ground Resistance Value?
What is a Good
Ground
Resistance
Value?
Answer:
The goal in ground resistance is to achieve the lowest ground resistance value possible, that makes sense economically and physically, when contacting the earth, also known as the soil/ground rod interface.
Ideally, a ground should be zero ohms of resistance².
However, there is not one standard ground resistance threshold recognized by all certifying agencies.
The NFPA and IEEE recommend a ground resistance value of 5 ohms or less while the NEC has stated to “Make sure that system impedance to ground is less than 5 ohms specified in NEC 50.56.
In facilities with sensitive equipment it should be 5ohms or less”.
