+1 310.318.7151

Mon - Fri: 9:00AM - 6:00PM

info@esgrounding.com

# What is the mathematical formula for calculating the resistance-to-ground of parallel electrodes? What is the mathematical formula for calculating the resistance-to-ground of parallel electrodes?

The simplified calculation for predicting the resistance-to-ground (earth) of a given length grounding rod is:

R=(p/(2*pi*L))*(ln*(4L/a)-1)) + (p/(2*pi*s))*(1-(L squared/3s(10X8)) + (2L(10×4)/5s(10×4)…)

Where:

• R= Resistance
• p= soil resistivity
• L = Length of the rod
• a= radius of the rod
• ln= natural log
• s = rod spacing

The above is the hand formula, however it does not take into account multi-layered soils.  We highly recommend using a computer program such as CDEGS.

The Engineering Experts at E&S Grounding Solutions

### Related Posts

#### What Are Some Typical Electrical Grounding Testing Procedures?

Mike asked:What types of preventative maintenance electrical grounding testing procedures do you recommend for electrical grounding systems and how often?

#### Grounding of metal buildings

PJ Asked:Inspector requires grounding of metal building, I plan to use a rebar in slab to tie to metal frame in another place?

#### What are the NEC Requirements for Grounding and Bonding Rebar?

Jake Asked:What are the NEC Requirements for Grounding and Bonding Rebar?