7 hours ago, Chris_S said:

1. Earthing your panels to your DB is no good as the panels are not in the AC system. Breakers won't trip. That's why we use DC over current breakers or PV fuses.

To the AC DB maybe, but to a ground rod, yes, in a fault where a DC conductor touches a piece of metal, it will allow the current to get back to the source in a parallel path, increasing current flow (because less resistance) and increasing the chances of the breaker / fuse doing its job and turning it off, making it safe.  

You may want to watch the video from start to end again, it's a lot to take in and I watched it at least 3x before everything made sense to me. I even made the list! 😁

Edited February 6, 20233 yr by YellowTapemeasure

18 minutes ago, YellowTapemeasure said:

To the AC DB maybe, but to a ground rod, yes, in a fault where a DC conductor touches a piece of metal, it will allow the current to get back to the source in a parallel path, increasing current flow (because less resistance) and increasing the chances of the breaker / fuse doing its job and turning it off, making it safe.  

You may want to watch the video from start to end again, it's a lot to take in and I watched it at least 3x before everything made sense to me. I even made the list! 😁

Getting a crazy headache thinking about this. Just say your PV wires or panels create a short to your rails and you touch your panels/rails or even climb on your metal roof you in trouble. So do you want that current to flow to your DB earth or to a ground rod? 

Most of us have fuses at the DC DB and not as close to the panels as possible. Is that current really going to go into the soil and not your body? 

28 minutes ago, Chris_S said:

Getting a crazy headache thinking about this. Just say your PV wires or panels create a short to your rails and you touch your panels/rails or even climb on your metal roof you in trouble. So do you want that current to flow to your DB earth or to a ground rod? 

Most of us have fuses at the DC DB and not as close to the panels as possible. Is that current really going to go into the soil and not your body? 

Take the human shock aspect out of it, and think about it as a fault only. Current returns to the source. It does not go into the soil / earth. It may use the earth /ground path to get back to the source. It will use anything that it can to get back to source.

In a fault, the current will use the ground to get back to the source, creating a secondary path. Because there is two paths, there is less resistance (Ohm's law) and greater current, which hopefully trips the breaker / fuse.

You honestly need to watch the video, from start to finish, and I say this respectfully. Get a notebook and a pen, and watch it from the beginning. You will thank Mike Holt later, I did.    

Edited February 6, 20233 yr by YellowTapemeasure

23 hours ago, BritishRacingGreen said:

@coffeedogsjujitsu while this is a public forum where opinions and informal comments are most welcome, I do feel you should have done a slight more homework and research before making a bold statement this.

Let me help you here, you are not dealing with the reticulated neatral connection in your residential bounds. The frame substructure of pv has no reference to your live and earth-bonded neatral. We are trying to earth these frames against lighning surges and plus minus nothin else. 

And no, the roof will only blow off  in the Netflix movies. 

A very long time ago, when I was involved with selling millions of lightning arrestors and varistors and were involved in helping with insurance claims and arguments for customers, I came to a different conclusion. Lighting is 95 % from cloud to earth and while the earth potential is the greatest the lightning is "slowly" searching for the best voltage potential and is not just one line of the shortest distance between your solar panel and the lightning striking cloud. We came to the conclusion that if there is a better route for the lightning to go to earth, around your solar panels and other very good earth connection, it will go there. Thus a lightning pole close by, could be a better solution for a badly earthed solar panel system than the best earthing in the area, you definitely will attract your lightning strike. With the 50.000 to 60.000 Ampere flowing close to your electronics it will be fried potatoes. have a look around your house, is there a better point for the lightning to dispose of the charge or are you the best conduction earth. I personally will earth my solar panels very badly, but ensure that there is a much better route close by for the lightning strike to go to earth. There is a pole close to my hose much higher than my roof and that I make a good earth. Or as an alternative I have a 200 KV plus potential low current pointer above the panels and protect my panels in that way. Only over the sea there are lightning strike from the sea to the clouds . I will take my chance a have a bad earth and protect my electronics. Bert 

By the way the lightning just passed our house at the coast. 

40 minutes ago, BertKu said:

A very long time ago, when I was involved with selling millions of lightning arrestors and varistors and were involved in helping with insurance claims and arguments for customers, I came to a different conclusion. Lighting is 95 % from cloud to earth and while the earth potential is the greatest the lightning is "slowly" searching for the best voltage potential and is not just one line of the shortest distance between your solar panel and the lightning striking cloud. We came to the conclusion that if there is a better route for the lightning to go to earth, around your solar panels and other very good earth connection, it will go there. Thus a lightning pole close by, could be a better solution for a badly earthed solar panel system than the best earthing in the area, you definitely will attract your lightning strike. With the 50.000 to 60.000 Ampere flowing close to your electronics it will be fried potatoes. have a look around your house, is there a better point for the lightning to dispose of the charge or are you the best conduction earth. I personally will earth my solar panels very badly, but ensure that there is a much better route close by for the lightning strike to go to earth. There is a pole close to my hose much higher than my roof and that I make a good earth. Or as an alternative I have a 200 KV plus potential low current pointer above the panels and protect my panels in that way. Only over the sea there are lightning strike from the sea to the clouds . I will take my chance a have a bad earth and protect my electronics. Bert 

By the way the lightning just passed our house at the coast. 

I get what you saying. I can take it even  further by stating that arrestors place in a wrong position can and will invite surges to actually enter a power supply  and burn thru the electronics to find the low earth impedance of that arrestor. 

In the case of pv panels unfortunately we have the situation where the pv dc wires are actually switched  onto  live and neatral on a per 50hz cycle basis. This is courtesy of the fact  that most inverters are transformerless. And you know how close that pv wires are to the frames as it is routed. So here we would rather have a deterministic good quality earth on the frame, as opposed to be  subjected to flashover to the pv minus or plus. 

This is what can happen when lightning strikes.. the molten mass at the bottom is the remains of a 3-phase professional lightning surge arrestor. 

Did it work? Well, nothing in the house got fried so you could say that yes, it did it's job.

These two videos explain everything in detail and are really well presented. 

23 hours ago, BritishRacingGreen said:

I get what you saying. I can take it even  further by stating that arrestors place in a wrong position can and will invite surges to actually enter a power supply  and burn thru the electronics to find the low earth impedance of that arrestor. 

In the case of pv panels unfortunately we have the situation where the pv dc wires are actually switched  onto  live and neatral on a per 50hz cycle basis. This is courtesy of the fact  that most inverters are transformerless. And you know how close that pv wires are to the frames as it is routed. So here we would rather have a deterministic good quality earth on the frame, as opposed to be  subjected to flashover to the pv minus or plus. 

Yes, it is one of the most difficult subjects and the CSIR some 40 years ago did some incredible nice research conclusions. Somebody mentioned, can he use 5 mm2 cable. Let say he is good and get a resistance of 0,1 Ohm. With a lightning strike of 60.000 Ampere, you looking at still 0,1 x 60000 = 6000 Volt on your panel. Not ideal. Thus if you earth it, the thickest copper cable you can afford.   The CSIR figured out that the best way in protecting thatched roof house is by two or 3 very high poles with excellent earthing, which created a neutral 45 degrees field, and with the thatched house in the neutral zone, no fires were recorded.  One thing is for sure, one should try to create a Faraday cage around his electronics. .

I love to put some very high poles around my house, but how long will it take before a neighbor is complaining at the municipality and I have to take it down? For me the best is that my neighbors have better lightning protection than me, then I will only have to worry about surges. One has to obey with the law, but how good were the people who propose the rules? if I was on a farm, i would put some  good high lightning poles up and have the solar panels in the neutral field  Bert

On 2023/02/04 at 11:06 AM, Chris_S said:

Can I use 1 spike for all strings? And do you know if I must use bare copper cable or will insulated 6mm2 house wire be OK? 

I fully agree, I have been speaking to 4 electricians and I am very concerned, that many people will have problems with their endurance, should it be hit by lightning. I personally am busy t put a separate spike into the ground as deep as possible 2 feet away from the building wall, with a 10 mm2 copper cable in a protection pipe going up to my roof and then at 45 degrees to the top of the solar panel frame,  then with a spike to be higher (+/- 80 cm) than the top of the solar panels, ( IF I have the money I will gold plated, but sadly I don't have the money for that..  and then with a small, thin wire or lightning arrester from panel frame to spike on top of the solar panels, to ensure it is also earthed. What do you think about this way I am going to do it?     Bert . 

5 minutes ago, BertKu said:

I fully agree, I have been speaking to 4 electricians and I am very concerned, that many people will have problems with their endurance, should it be hit by lightning. I personally am busy t put a separate spike into the ground as deep as possible 2 feet away from the building wall, with a 10 mm2 copper cable in a protection pipe going up to my roof and then at 45 degrees to the top of the solar panel frame,  then with a spike to be higher (+/- 80 cm) than the top of the solar panels, ( IF I have the money I will gold plated, but sadly I don't have the money for that..  and then with a small, thin wire or lightning arrester from panel frame to spike on top of the solar panels, to ensure it is also earthed. What do you think about this way I am going to do it?     Bert . 

sorry my mistake not 10 mm2 but 10 mm thick copper cable like welding cable . 10 mm z 10 mm x 0,785 = 78,5 mm2 

21 minutes ago, BertKu said:

sorry my mistake not 10 mm2 but 10 mm thick copper cable like welding cable . 10 mm z 10 mm x 0,785 = 78,5 mm2 

This represent approx 0,0085 Ohm per 10 meter of 10 mm copper and that at 60.000 Ampere lightning strike (measured in Joburg a number of times) gives you a potential of 500 Volt. I can live with that.  But there will be connection resistances and that is very difficult to measure.

Did anyone attend the Segen presentation on Hubble batteries?

Anyway, the item that fascinated me was on earthing and bonding given at the end of the presentations given by a learned man whose name I cannot remember at present.

He was pointing out that earthing and bonding were not the same thing. Bonding is where each item it connected together so that no potential can exist between components, This is important to prevent human harm as well a electrical damage to electronic equipment.

Then there is earthing. This should be done at only one point in a system. He gave examples how cows have been electrocuted at a distance from  distance from the lightning strike. The strike creates a spreading pool of potential as it dissipates into the ground.  There is a difference in potential created between the legs which electrocutes them.

If we put multiple earths in the ground a nearby lightning strike will do the same thing. It will create potential differences between the earth rods causing damaging currents to flow between components .

The point he then made was that we bond the equipment only to the incoming utility earth. South Africa has violent electrical storms on the highveld and I remember and years back Escom built a new national control centre. While the structure was securely earthed, all electrical equipment was bonded to an earth "mecca".

More strikes occur to nearby objects than directly to panels. If there is a direct strike, everything is fried anyway. Rather protect using appropriate lightning conductors direct to ground.

1 hour ago, IanO said:

Then there is earthing. This should be done at only one point in a system.

Correct. Those that are not using a proper earth neutral bridge relay on Sunsynk / Deye installs, and instead creating a permanent earth are courting disaster.

On 2/4/2023 at 11:06 AM, Chris_S said:

What is the SANS rules on this? 

Can panels be connected to house earth or must they have a dedicated earth spike. 

My home earth is connected to utility earth and a ground spike. Can I just use this existing ground spike? 

The SANS (South African National Standards) 10142-1 regulations dictate the electrical installation requirements in South Africa. According to these regulations, electrical panels must be connected to an earth electrode system that is separate from the earth electrode system used for the main earthing of the building. This separate earth electrode system must consist of one or more electrodes, such as ground spikes, that are driven into the ground.

Regarding your question, if your home's earth is connected to the utility earth and a ground spike, you can use this existing ground spike to connect the electrical panel. However, it's always advisable to consult with a qualified electrician to ensure that the installation meets the relevant safety regulations and standards.

On 2023/02/04 at 4:10 PM, Dylboy said:

Not quite as you would require to do an earth resistance test but the result required is not published, anything around 12ohms is good but to get that you may have to drive a 59meter rod... 

From what I have been reading and learning with other sparks and documents is that if you use an earth spike you need to still bond it with the installation earth, so with that just run the earth cable to the earth of the DB. So if you want run a spike but also a cable to the DB. 

 

The honest answer is there is no answer and it is what ever that spark is happy to sign. 

 

Thing is bonding is done to 2ohm, and minimum of 2.5mm cable, lighting protection is 16mm and 6mm depending. 

At the end of the day ask the spark who is going to do the CoC.

 

The honest truth is any installation done DIY should not get a CoC at all as it was not done under the general controll of a wireman... Only if property is sold would a CoC then be conducted.

There are loop holes galore and no public knowledge and the industry as a whole is confused and it's the wild west. 

 

So do what ever the spark wants who will sign it off for you. Insurance also don't care and just want the paper as a tick box. 

Well said. Saw a R2m solar installation explosion. No COC. Not done by an electrician but a PV greencard installers. Everybody think thy can do a DIY. Case 

On 2023/02/12 at 6:43 PM, Vernonstanley said:

The SANS (South African National Standards) 10142-1 regulations dictate the electrical installation requirements in South Africa. According to these regulations, electrical panels must be connected to an earth electrode system that is separate from the earth electrode system used for the main earthing of the building. This separate earth electrode system must consist of one or more electrodes, such as ground spikes, that are driven into the ground.

Regarding your question, if your home's earth is connected to the utility earth and a ground spike, you can use this existing ground spike to connect the electrical panel. However, it's always advisable to consult with a qualified electrician to ensure that the installation meets the relevant safety regulations and standards.

What section, page number is that on ? 

According to me and my understanding is all earth rods need to also be joined to the main earthing terminal so to keep same equipotential.

But I want to double check, I spoke with an engineer at a Segen event and he too said if you spike for panels that too must be bonded to your main earthing terminal.

But if you can let me know the section I can go back and read as we all human

Sans 60364,  Section 712.542.102 (page 49) .... If a separate earth electrode is provided for the PV array, it shall be connected to the main earthing terminal of the electrical installation......

11 minutes ago, Superfly said:

I was also under the impression a separate spike was required for the high voltage PV strings but this from SANS 

I have a second spike (from panels) in close proximity to the house's spike which is beneath the meter box - I'm thinking maybe I should put it on one?

 

 

My electrician also said I must use the main house earth. 

Real truth is nothing can stop the mighty power of a lightning strike. To cover yourself against your insurance wanting to dodge paying out for replacement & any other regulatory bodies just ensure your panels are connected to a copper earth rod via a pvc pipe and that from the panels, no wiring goes through your roof/ceiling for added measure & comfort. Anything else, I’ll have to say, “God’s case, no appeal”🙆🏾

On 2023/02/05 at 7:23 PM, BritishRacingGreen said:

@coffeedogsjujitsu while this is a public forum where opinions and informal comments are most welcome, I do feel you should have done a slight more homework and research before making a bold statement this.

Let me help you here, you are not dealing with the reticulated neatral connection in your residential bounds. The frame substructure of pv has no reference to your live and earth-bonded neatral. We are trying to earth these frames against lighning surges and plus minus nothin else. 

And no, the roof will only blow off  in the Netflix movies. 

First of all correct your spelling errors. what is a neatral?

   When lightning strikes a building, it produces an enormous high voltage in the grounding conductors due to the inherent fast rise time of the discharge. Hence the high potential is developed between the system earthing and lightning protection earthing, which leads to cause unsafe situations for both personnel and other equipment connected.

     Another problem with an isolated ground is that the ground resistance of a system, which uses one or more electrodes, could be much higher than the common ground ratings. So lightning Protection earthing and system earthing should get bonded together in a ground level to make a low resistive path for all forms of grounding within a building.

17 minutes ago, coffeedogsjujitsu said:

First of all correct your spelling errors. what is a neatral?

   When lightning strikes a building, it produces an enormous high voltage in the grounding conductors due to the inherent fast rise time of the discharge. Hence the high potential is developed between the system earthing and lightning protection earthing, which leads to cause unsafe situations for both personnel and other equipment connected.

     Another problem with an isolated ground is that the ground resistance of a system, which uses one or more electrodes, could be much higher than the common ground ratings. So lightning Protection earthing and system earthing should get bonded together in a ground level to make a low resistive path for all forms of grounding within a building.

Mike Holt also explains this and has pictures of roofs that are destroyed

Edited April 1, 20233 yr by coffeedogsjujitsu

12 hours ago, coffeedogsjujitsu said:

First of all correct your spelling errors. what is a neatral

To be direct but fair, if you are focussing on a stupid small spelling mistaik  and not the semantics behind the sentence, then its not worth for us to rub shoulders on this subject. Sarcasm is not my forte. 

Edited April 2, 20233 yr by BritishRacingGreen

How many installations are done using a separate earth rod for the frame of the panels yet the PV SPD Earth is connected to utility earth. 

All I can say to this subject is that if your electrician is required to perform earth measurements for the purposes of issuing a COC, I would recommend doing so after you had some good soaking rain.  That should make the figures pass with flying colours.  Otherwise you might need some very long earth spikes.  Not so?

30 minutes ago, Leshen said:

How many installations are done using a separate earth rod for the frame of the panels yet the PV SPD Earth is connected to utility earth. 

Plenty. And to me it makes sense. The pv dc becomes part of the buildings electrical system, mainly due to the inverter being transformerless (Sunsynk / Axpert). So it make sense to protect this system using equipment grounding on the SPD. 

But the frame is a floating mechanical island with no reference to system ground (neutral) or equipment ground (earth).  So a seperate earth does not comprimise system/equipment grounding routes. 

Edited April 2, 20233 yr by BritishRacingGreen