heirloom hamlet
life my way
Is it necessary to drive a long copper grounding rod into the ground and connect it to a small system? For instance, a 24v MPPT, connected to max 1500w 110v 20a in the panel array.
Grounding Rod Necessary
- Thread starter heirloom hamlet
- Start date
svetz
Works in theory! Practice? That's something else
Yes, the grounding rod will bleed off the static electricity generated on a fixed structure as wind flows past it. ref
Small arrays will build up as much static voltages as a big one, but they won't have as much current.
But since you're outside the US check your local codes, not sure but static discharges usually aren't a problem in areas with a high humidity. (I have high humidity, but grounding rods are still code here).
Most homes will already have one, you just need to tie into it. Usually (not always) it's around where the electrical service entrance is. If not there, check around where the water main enters. Code in the U.S. is generally 8', but some places with little moisture or high soil resistivity need a whole lot more.
Small arrays will build up as much static voltages as a big one, but they won't have as much current.
But since you're outside the US check your local codes, not sure but static discharges usually aren't a problem in areas with a high humidity. (I have high humidity, but grounding rods are still code here).
Most homes will already have one, you just need to tie into it. Usually (not always) it's around where the electrical service entrance is. If not there, check around where the water main enters. Code in the U.S. is generally 8', but some places with little moisture or high soil resistivity need a whole lot more.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
/s Why would anyone want to ground their electrical system, gee I wonder ? //s
A grounding Rod or Plate is pretty essential if you want a safe system. Vehicles are not grounded because they are isolated thanks to the rubber tires, but if your on land then you better ground.
A grounding Rod or Plate is pretty essential if you want a safe system. Vehicles are not grounded because they are isolated thanks to the rubber tires, but if your on land then you better ground.
Structure voltage imbalances HURT! Believe me... you may not get electrocuted... but mild shocks, or equipment damage are serious too... not to mention shocks causing you to otherwise injure yourself...
Ground it.
Ground it.
What environment is your system in? For example, my PV panels are mounted to my caravan, with the negative line earthed to chassis, which in turn gets an earth via a grid connection. I personally don't use a grounding rod. If I use my genset, then, yes, I do ground that.
jasonhc73
Cat herder, and dog toy tosser.
heirloom hamlet
life my way
Really helpful, everyone, thank you.
Right now, I have 3 separate MPPT systems functioning, really just for battery capacity testing, through my enclosed 24' trailer Big Red. So it seems grounding is being accomplished through the 4 tires.
Ultimately, though, the systems are for some micro cabins I will be building, so looks like I'll need to ground at that time.
The design will be the 3 systems staged in a sort of a "pumphouse" built just for them, so the panels can be placed in good sun but close proximity. Then I'll run a 10awg cord less than 100' to each cottage to provide the modest electrical needs.
I should be able to just run a single ground rod near the pumphouse and connect each system to it, correct? No need to ground individually at each building?
Right now, I have 3 separate MPPT systems functioning, really just for battery capacity testing, through my enclosed 24' trailer Big Red. So it seems grounding is being accomplished through the 4 tires.
Ultimately, though, the systems are for some micro cabins I will be building, so looks like I'll need to ground at that time.
The design will be the 3 systems staged in a sort of a "pumphouse" built just for them, so the panels can be placed in good sun but close proximity. Then I'll run a 10awg cord less than 100' to each cottage to provide the modest electrical needs.
I should be able to just run a single ground rod near the pumphouse and connect each system to it, correct? No need to ground individually at each building?
Attachments
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Rubber I san insulator it cannot conduct any electricity.
If you have a physical "PumpHouse" which has a Steel Well head in or near it, a Well Casing is allowed to be used as a Ground in many Jurisdictions. Check with your codes.
MichaelK
Solar Wizard
I believe in some jurisdictions, the code requirement is two 8' grounding rods, connected SERIALLY to each other. My understanding of the grounding code is that there may be multiple below-ground grounding points, and multiple above-ground attachment points, but all the above-ground points are connected to the below-ground points at one single junction only. If you do not do this, the grounding system becomes a lightning attractor! Let's say you pound a rod along side the foundation of the building on the right side of the house. You could then pound a second rod 10' out from the foundation, still on the right side, and connect the two rods via a solid copper wire. Your above ground grounding wire gets attached to the nearest ground rod only.
What you must NOT do is drive one rod on the right side of the building, and another rod on the left side of the building, connecting the two rods at two different places along the above-ground grounding wire.
What you must NOT do is drive one rod on the right side of the building, and another rod on the left side of the building, connecting the two rods at two different places along the above-ground grounding wire.
Actually, no.
The grounds MUST be connected to an unbroken grounding conductor. The water pipe, and BOTH ground rods spaced at LEAST 6 feet apart, must be connected to a single unbroken grounding conductor.
What you must not do is have individual grounding systems unconnected...
Earthing rules are a science in themselves. I've never really understood why current flows through the earth, I mean, it's just dirt and rock! Not the best conductors known to man! Why would anybody choose a TT earthing system? (rhetorical).
10awg wire at close to 100'? That's a small wire for such a long run. You did not specify DC or AC going to each location, or what the "modest loads" would be. If its AC, can you be sure that a sixteen year old girl won't sneak in a hair dryer? If its DC, and just for a few lights it should be ok, but anything more would be a problem. Lower current means higher amps...and melty 10awg...
GVSolar
Solar Enthusiast
- Joined
- Jan 6, 2020
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Could I get more detail on the minimum spacing for dual ground rods? I have two rods spaced 3 feet apart (due to only three feet penetration depth). What is the reasoning on the separation - and lightning attraction. These are equipment ground rods for a 3kw panel array.
Array ground is different.
The twin ground rods spaced minimum of 6' apart is for breaker panel grounding
offgriddle
"FOREVER BEGINNING"
As soon as I saw the statement, "grounding will be achieved through the tires", I dove into my foxhole knowing full well what was about to follow for responses to such a fundamental boo boo.
offgriddle
"FOREVER BEGINNING"
Sometimes I have dug down to the wet soil level and laid ground rods horizontally in a trench .. forgive me.
Yup, this is an acceptable alternative... as is driving the rods at a sharp angle when bedrock is encountered...
MichaelK
Solar Wizard
What is the definition of "an unbroken grounding conductor"?
