Help economical for grounding rod

[Dongbites]

I want to study power system analysis to lessen the grounding rod from my different projects and also to add more credentials for every design i made, does anyone can help where i can start or what to focus to get the right calculation of it. From short circuit of the ground, settings of the time tripping of the breakers, and economical numbers of rod

 

[Master Nater]

grounding electrodes (including rods) are not installed to provide fault current of our electrical systems. they are installed to be a dump-path for static electricity to return to the earth.

equipment grounding conductors are installed to clear overcurrent devices.

 

[Dongbites]

grounding electrodes (including rods) are not installed to provide fault current of our electrical systems. they are installed to be a dump-path for static electricity to return to the earth.

equipment grounding conductors are installed to clear overcurrent devices.

Yup i want to know how many rods should i need and to compute it

 

[Master Nater]

ok. what electrical standard are you on in the phillipines?

here, i simply install a single 8' x 5/8" rod (or other grounding electrode), attach it to the utility neutral and then use a simple ground rod tester like this ... https://www.amazon.com/ETCR-ETCR2000A-Resistance-Measurement-0-010Ω-500Ω/dp/B0FBLWFSWT/

works great every time. just had one come out to 8.6 ohms today. but i'm not in a rocky terrain.

if the electrode is under 25ohms resistance, then you're done. if it's higher than 25ohms, install another at least 6' away. then, you're done. no need for more than 2 rods, by our code book.

if you don't have access to a clamp-on tester like this, you can isolate the ground electrode and apply a known voltage to the isolated rod. take a reading of the ampacity flowing through the rod, apply it to ohms law, and you can calculate the resistance through the earth using ohms law. disclaimer: beware of electrocution hazards. but you're a design engineer, so you know what you're doing. right?

ohms law ---> resistance = voltage / amperage

 

[Dongbites]

ok. what electrical standard are you on in the phillipines?

here, i simply install a single 8' x 5/8" rod (or other grounding electrode), attach it to the utility neutral and then use a simple ground rod tester like this ... https://www.amazon.com/ETCR-ETCR2000A-Resistance-Measurement-0-010Ω-500Ω/dp/B0FBLWFSWT/

works great every time. just had one come out to 8.6 ohms today. but i'm not in a rocky terrain.

if the electrode is under 25ohms resistance, then you're done. if it's higher than 25ohms, install another at least 6' away. then, you're done. no need for more than 2 rods, by our code book.

if you don't have access to a clamp-on tester like this, you can isolate the ground electrode and apply a known voltage to the isolated rod. take a reading of the ampacity flowing through the rod, apply it to ohms law, and you can calculate the resistance through the earth using ohms law. disclaimer: beware of electrocution hazards. but you're a design engineer, so you know what you're doing. right?

ohms law ---> resistance = voltage / amperage

Thank you sirr so much appreciated

 

[kwired]

Yup i want to know how many rods should i need and to compute it

Depends what the goals are. General use one is likely fine, NEC seems to think you need to prove it is 25 ohms or less or add a second one, but doesn't require you drive any more even if you don't achieve 25 ohms with the second one. Some specific items/situations may call for lesser resistance- usually by manufacturer or designer and not by general rules of the industry. specific i