Please Review my ground and lightning protection system

Thread Starter

meowsoft

Joined Feb 27, 2021
116
Please review my ground and lightning protection, also give some advice

Question 1, can my lightning counter also count lightning came from lightning rod 2 ?
Question 2, is auxiliary ground that bonded to grounding grid is a good idea ?, that use steel rod (building residual material), not standard rod
Question 3, if lightning occurs can lightning surge enter electricity wire ?, if soil was fail to absorbs spike voltage from lightning, is this can happen ?

All Bare Copper Conductor (BC) is made from pure copper, lightning rod 1 is copper bonded, lightning rod 2 is pure copper
Lightning rod 1 and 2 is also pure copper 3/4" 60cm, water table is only 70cm under soil surface, so soil can absorbs lightning current very good, earth resistance is only 0.192 ohm
Lightning arrester used is SPD type T2, and SPD type T3 in special branch circuit
 

sagor

Joined Mar 10, 2019
394
If BC stands for standard round copper wire, not the best choice for lightning protection, though better than nothing. For better protection you should be using copper strapping, at least 2" wide (50mm) or even wider if possible. Copper strapping has lower inductance than equivalent area copper wiring (round). Remember that lightning is not just DC voltage, it contains lots of RF frequencies up into the MegaHertz ranges.
A ground rod only 0.5M deep is also a rather poor choice. It should be deeper/longer into the ground. Water table has little effect in dissipating a lightning hit, as most water has high resistance unless heavily doped with minerals/salts.
A resistance of 0.192 ohms with an average 20kA lightning hit will produce 3840 volts across where you measured the 0.192 ohms. That is enough voltage to do some serious arcing. An open arc can easily cause a fire. Some lightning can produce 30kA and up to 100kA or more. You do the math...
 

Thread Starter

meowsoft

Joined Feb 27, 2021
116
If BC stands for standard round copper wire, not the best choice for lightning protection, though better than nothing. For better protection you should be using copper strapping, at least 2" wide (50mm) or even wider if possible. Copper strapping has lower inductance than equivalent area copper wiring (round). Remember that lightning is not just DC voltage, it contains lots of RF frequencies up into the MegaHertz ranges.
A ground rod only 0.5M deep is also a rather poor choice. It should be deeper/longer into the ground. Water table has little effect in dissipating a lightning hit, as most water has high resistance unless heavily doped with minerals/salts.
A resistance of 0.192 ohms with an average 20kA lightning hit will produce 3840 volts across where you measured the 0.192 ohms. That is enough voltage to do some serious arcing. An open arc can easily cause a fire. Some lightning can produce 30kA and up to 100kA or more. You do the math...
NOT 0.5M, 0.5M DEEP UNDER SOIL SURFACE, BUT IS HAVE 12M LENGTH, about 31 foot, better than NEC 8 foot requirements
 

Thread Starter

meowsoft

Joined Feb 27, 2021
116
If BC stands for standard round copper wire, not the best choice for lightning protection, though better than nothing. For better protection you should be using copper strapping, at least 2" wide (50mm) or even wider if possible. Copper strapping has lower inductance than equivalent area copper wiring (round). Remember that lightning is not just DC voltage, it contains lots of RF frequencies up into the MegaHertz ranges.
A ground rod only 0.5M deep is also a rather poor choice. It should be deeper/longer into the ground. Water table has little effect in dissipating a lightning hit, as most water has high resistance unless heavily doped with minerals/salts.
A resistance of 0.192 ohms with an average 20kA lightning hit will produce 3840 volts across where you measured the 0.192 ohms. That is enough voltage to do some serious arcing. An open arc can easily cause a fire. Some lightning can produce 30kA and up to 100kA or more. You do the math...
It even was make inspection personnel very shocked, because normal house residence is only 4 feet to 8 feet length, BUT THIS IS 31 feet, even there is no lightning protection needed in normal situation, that area is "LOW LIGHTNING RISK", even neighbor building that has 3 floor doesn't have lightning arrester, and this project building is only have one floor, and that make inspection personnel very very shocked, even more 95mm2 bare copper is very good in my area (even medium voltage (24kV) load break switch only use 50mm2 bare copper in my area), and requirements is only 50mm2, but I am very perfectionist, I want to develop system that very very perfect, also in China this home electrical installation cost about 1920% than average home, and I was lost many many project's because my concept is over over secure, residential home with factory grade installation, and in China copper strap is cost very high, I can lost my project again if I change that with copper strap
 
But....only 0.5M is in the ground? That would make it a 0.5M ground rod with long above ground conductor if I understand what you say.

Is your electrical system grounded? In most places they expect only one ground rod per electrical system. I'm no expert, just going by what I've heard and read informally.
 

Yaakov

Joined Jan 27, 2019
2,342
You might want to consider using spark gap arresters to prevent the conducting wires from becoming paths for the lightning.
 
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Thread Starter

meowsoft

Joined Feb 27, 2021
116
But....only 0.5M is in the ground? That would make it a 0.5M ground rod with long above ground conductor if I understand what you say.

Is your electrical system grounded? In most places they expect only one ground rod per electrical system. I'm no expert, just going by what I've heard and read informally.
No !, Is in 12m meters inside ground + 0.5m, 12.m
 

Thread Starter

meowsoft

Joined Feb 27, 2021
116
But....only 0.5M is in the ground? That would make it a 0.5M ground rod with long above ground conductor if I understand what you say.

Is your electrical system grounded? In most places they expect only one ground rod per electrical system. I'm no expert, just going by what I've heard and read informally.
Ground.png
 

Thread Starter

meowsoft

Joined Feb 27, 2021
116
Thick 0.5 meters line is 95mm2 bare copper wire, also local code only require 50mm2, and even 24kv load break switch system in utility's pole is also use 50mm2 bare copper
and burried copper wire nor down conductor is also permitted by local code, I don't know if doesn't permitted by NEC, so that electrode is placed 0.5 m under soil surface level, to prevent copper theft... copper theft rate is moderately high
 

Thread Starter

meowsoft

Joined Feb 27, 2021
116
and burried copper wire nor down conductor is also permitted by local code, I don't know if doesn't permitted by NEC, so that electrode is placed 0.5 m under soil surface level, to prevent copper theft... copper theft rate is moderately high
And BC wire is inside PVC pipe, so thief is think that is normal water pipe
 

Thread Starter

meowsoft

Joined Feb 27, 2021
116
You might want to consider using spark gap arresters to prevent the conducting wires from becoming paths for the lightning.
OK... do you thing make zero resistance down conductor is possible ?, I add 8 meters more ground rods, now 20 meters, and resistance is only 0.01491 ohm, It is possible to reach 0.0 ohm resistance ?, is that 0.01491 ohm resistance is very good ?
 

Yaakov

Joined Jan 27, 2019
2,342
OK... do you thing make zero resistance down conductor is possible ?, I add 8 meters more ground rods, now 20 meters, and resistance is only 0.01491 ohm, It is possible to reach 0.0 ohm resistance ?, is that 0.01491 ohm resistance is very good ?
You can't have 0Ω resistance. The conductor has resistance per unit distance. But, you also aren't just concerned with DC resistance, lightning is pulsed and impedance is a concern, that's one reason for the geometry of grounding wire.
 
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