Hi from Germany! Just a heads up from an electrician, who did close to nothing else but safety measuring electric gear and buildings: During measuring of the resistance of the grounding, you need to absolutely ensure the measuring current is at or above 200mA. In machine building they recommend even 10A straight. Yes, you read that right. I don't believe your tester there does provide that amount of energy for that, so these testers you referred to do have their eligibility...
One of Andy's bench supplies could do it. 1 ohm, 1A = 1V drop. 1 ohm, 10A = 10V drop ... yah, a 5A or 10A CC/CV supply could do it. They can usually go up to 30-40V or so. That would be good for up to around 3 ohms. But he would have to make sure that the supply is isolated from the mains, otherwise there is an alternative path to ground through the neutral-ground bond. The voltage drop can be used to calculate the approximate resistance as well as double-check that the ground path is solid. And one can look at the junctions (wire meets screw, etc)... bad connections will have excessive heating.
@@junkerzn7312 Sorry, but I deem that a little bit dangerous. Professional testing gear does have some safety built in and that's one part of why that is so expensive (I'm talking about the real stuff, not the cheaper gear Andy referred to). The other part is brand naming. Only a little part of the price to pay is the actual hardware, the R+D or the marketing...
@@wiedapp Mmmm. Lets just say that alarm bells don't go off in my head when we're talking about < 50V and current that is already mostly flowing through a low-impedance path. I think it is low risk on both accounts. But I'll grant you that a dedicated tester will be safer since the bench supply more or less runs the current continuously while switched on and a dedicated tester does not. But again.... cost. And if you are testing junction temperatures at the screw terminals and so forth, you have to run a continuous current anyway. -Matt
Agreed. In the high voltage industry we normally use 100A current to test contact resistance, and the test is referred to as a ductor test. Check out the Megger MOM2. Very clever piece of equipment that fires up to 200A through to give you a reading in the microohm range, and it is surprising small and light.
Hi Andy Im from Adelaide SA according to NECA and Clean Energy Australia plus AS 3000 placing them washers under the panels is not enough. Thats only mechanical connection you need to have what is called electrical connection for that you need main Earth to the railing and from that Earth you need individual Earth to the each panel. That ruling came out December 21 also the Earth measuring is taken from the main Earth stake that way you know all the Earthing is correct. Love your videos keep up the good work kind regards from South Australia.
if you extend both wires of one probe the tester will measure the resistance from probe to probe without the cable resistance, thats the reason for the sense cables😉 greetings from sunny hot germany 😎
Andy, next time you get bit or feel a cold coming on use a cue stick cotton swab soaked in hydrogen peroxide. Use it to clean your nasal passages if you feel a cold coming on and your ears for an earache works great.
Sehr schön.. 2 Videos an einem Abend.. Und ich hab kein Netz auf meinem Parkplatz 😥 hab aber viele StandBilder von dir...😋 Ja Erdung is wichtig. Ich hatte Modulklemmen wo die höllische unterlegScheibe gleich dran war... Nach nem jahr hatte ich nochmal gemessen. Und die Ergebnisse waren fast identisch...schön das du es allen mal ganz genau zeigst. Jedoch wundert mich die konstanten 1, 77 Trotz der langen Wege.. Ich hatte Unterschiede zwischen ersten und letzten Modul.. Bei dir is ja alles quasi gleich.. Bisl komisch 😎
Das ist ja alles mite dem Dach und dem anderen Metall verbunden. Und wie genau das Geraet misst, weiss ich nicht, aber es war bisher kein Ausreisser dabei, der mir ueber 2Ohm angexeigt hat.
You could use your power supply set at 10 volts and 100 milliamps (on ground to test) and read the volt drop from point to point accurately as ohms with your meter.
Excellent Demonstration Andy.Well Done!. I'm thinking your internal resistance meter will give you a better idea of ground continuity than a low voltage OHM function on a Digital Multi-meter. As your system relatively low current I say your tests should be adequate. I've got a bit of experience installing and testing grounding systems and grids for large power generation and distribution systems, and actual ground impedance in a multi megawatt AC generation system in operation can be quite different than measuring static resistance, but in your case I Say good enough. In fact, I'm not really sure if a commercial High resolution earth tester would tell you anything meaningful if you used one. I've used industrial MEGGER units like the DET2 that could give you indications that your system is unacceptable if you did not understand what is was you were doing. Sort of like measuring resistance on a 100m of 18 gauge wire with 50amps seeing a lot of resistance. Conversely, you could measure 'good' ground connections for a 200 amp service with 5ma using a DVM, and read .5 OHM, and conclude you have a ground, but would it hold up to a 50amp or 200 amp fault to ground, or a 1,000 to 10,000 amp surge to ground without blowing or melting a ground connection apart? Safe and adequate grounding is about proper sizing and ability to handle shorts to ground that a system is capable of producing without creating voltages on any part of exposed metal that people could come in contact with when things go "Bang', 'Buzz', or 'Sizzle' Good Stuff Andy, Thanks! Btw, I just found this instruction on using the MEGGER DET2 for those are wondering about the use and purpose for using a professional earth tester: ua-cam.com/video/wXbtvJF-zyA/v-deo.html
Just wondering and not taking into account the regulations, WHY and WHAT is the purpose to ground the metal parts of a solar array? There is not a a hard connection possible between the metal parts and the live of the grid. It might even improve the change of lighting strikes when the metal parts are grounded….. regards
All metal parts need to be grounded for electrical safety. This has nothing to do with lightning protection. Two different things. If you have an inverter in your system, you have 230V (or 120V) somewhere. There is always the chance that something goes wrong...
OK, this could possibly be made up "theoretically". However, the aluminum frame of a solar panel is completely insulated from the cells with their connections, see the double insulated symbol on the panel. So if a live phase ends up on the DC cables from the panel, there is still no reason to ground the frame. Moreover, there are solar arrays for off-grid use (as the off-grid garage) and there is no determined live (phase) at all anymore. Moreover, grounding the frame (on the roof) gives a risk-increasing aspect with regard to lightning strikes. nice discussion and keep up your most appreciated channel!
@@OffGridGarageAustralia It's not possible, your home is earthed, and power returns to it's source...you are worried about AC power, not DC, so it returns to it's source which is already grounded/earthed. It accomplishes nothing, but do it if it makes you feel better about "safety".. Describe the scenario where grounding a PV system has any "safety". A ground rod is 25ohms with respect to earth and at 120Vac can carry 5amps tops, where does the rest go? It's rhetorical, we know where the rest goes....and it's not to earth.
@@iamblaineful On a different channel, one person earth grounded his solar panels which was about 1k worth. Lightning struck close by and fried everything he had. AC has to be grounded in order to complete the circuit. You are absolutely correct that there is no need to earth ground DC whatsoever otherwise they will have a Lightning Magnet.
Clip leads also create problems when trying to measure small resistances. And inductance too.... if any of the wiring is coiled, that creates problems as well. And fingers as well... all sorts of problems. What I do is use WAGOs to connect the probes to the wiring to get a really solid contact. Or a screw-down if connecting to rail or conduit. The thin wire will cause problems too.... I usually have thousands of feet of ethernet cable sitting around so I just use an ethernet cable and strip and bind all 8 wires together (or in two sets of 4 wires each which allows me to loop it if I want to), to make a long cable. And I zero the meter out on the cable. WAGOs are great for gluing everything together so the measurements can be made hands-off. A non-precision meter also tends to be inaccurate when trying to measure small resistances, particularly if you have to do a relative measurement from a non-zero 'zero point'. That's one of the few cases where I pull out the 8845A for 6.5 digit accuracy. But it will probably work reasonable well for what you are testing as long as the resistance isn't in the gutter. Just make sure you have solid connections and its hands-free... no holding wires OR probes with your fingers while taking a measurement. Continuity... like Continential... Contin - new - ity (at least in American English). Hahaha.... reminds me of a very embarassing moment once when I was doing a lecture on RPN expression parsing 30 years ago and I said "Urinary" instead of "Unary". I don't think its possible for anyone to top that one! -Matt
But even with a 8845A, the problem still remains, the need of a decent test current to do such measurements. So tools like e.g. the MPK-257 from Sourcetronic or the Megger DLRO10HD are the better choice.
@@Frost4 Well, its a lot of money for a tool most of us almost never need to use. The 8845A does have a 4-wire measurement mode, but it is true that it is only 100mA. Still, it does have it. I think it is acceptable to do the resistance measurement and the current validation separately. As long as the results are relatively close to each other. The current validation can easily be done with a relatively uncalibrated bench supply.
Next time you've been bitten use vinegar directly on the spot it will directly neutralize the bite and the itching and swallowing will stops directly, works also for other insect bites, even red ants
"Press HOLD to enable the ZR function to measure internal resistance as low as 0.30-0.50 milliohms. The ZR function measures below 5 ohms, and the internal resistance is more accurate."
I have been told that the best way to use those special washers is to have them on alternative corners of the panels, which works really well when you have a string of panels and can share a washer between two adjacent panels.
Should you turn the grounding washer around. That way the clamp and panel are grounded. I see the washers appear to be cut out possibly to allow for the mounting bolt? Also, looks like your meter does have a "Zero" function. Great videos!
You need some pointy probes to get past the anodized coating. Very interesting....almost no conductivity with that coating when you install the panels. You really do need the funky washers or equivalent new version racking clamps that can pierce the coating.
wow didn't realize the Anodized aluminum is basically insulated aluminum. Although, if that is the case what is the reason to ground it? A stray wire comes into contact with the Anodized alum frame rail and...nothing happens since the coating prevents the power from the wire transmitting to the aluminum interior? unless there is a heavy scratch or high enough voltage to bridge? I used Galv unistrut for my installation, although I can't say I did it this way deliberatly to avoid anodized aluminums' insulation effect, nor did I deliberately drill the PV frames for mounting to the strut to ensure good ground, it just worked out that way LOL. I also never bothered to test the resistance from Ground to the rails/PV panels (until today!) since it seemed "obvious" that it should all be 'good' - thanks for sharing Andy, now I know I am all good instead of assuming it. Interesting from the comments the various regulations across jurisdictions for the grounding requirements. Like Arc-fault and Disconnect requirements, these are all different depending upon where you live it seems, perhaps we will see a convergence over the next decade of code requirements for PV everywhere.
Hi great content, dose all this grounding effect the bi metal insulation between different metals! And Increase corrosion! Which is why the rail feet are insulated in the first place.
It really is fascinating to see my posts randomly never appear to the public, but I can still see them if logged on. I guess someone somewhere just doesn't like me asking questions and making valid observations :)
Couldn you use the 4 point probes method (Kelvin Probe, 4T sensing) of the yr1035+ for the extension line ? That means 2 wires for the extension line and the resistance of the cable will be cancelled out.
@@OffGridGarageAustralia Yes 2 wires to the "on site" probe on the roof remain unchanged. The other two wires of the other probe will be extended and stay isolated from each other until the main ground bar, where they both are connected the ground bar independently.
@@OffGridGarageAustralia maybe it's just the rail systems that are common in the US that have them. All the major ones that I looked at used bonding clamps.
The earth washers connect the single solar panels to the rail. And you connect the ground cable to the rails. Otherwise you would need to ground every single panel.
how would you solve it, if there would be potential risk from lightning/flash impact? Is better to have grounding connected or is better to have it connected to lightning rod/conductor/termination (i don't know exact name of it).
Grounding is for electrical safety. Lightning Protection is for... well lightning protection These are two different things. LP is nothing for a DIY job any more and needs proper installation and testing.
Earthing is to stop you being electrocuted if there is a short to the metal. You'll feel it but it will take the path of least resitance down to earth so won't kill you. You have effectively created a lightening rod so need a lightening arrestor in your combiner box.
be kind, please tell me, I have an electric bike, in cells, lifepo4, 16 s, there is a big difference in current, what is being charged, what is being discharged, now I can't decide which, good, active, load balancer to buy ,
Here in the uk the earthling requirements for solar have changed several times...from nothing to more and more. I personally dont see the need to ground the panels..that's why we have earth free zones, however you do have a metal building so its probably harder to keep it earth free than to earth every thing.😑
Not earthing at all is dangerous. Especially with solar and high DC voltages. Some people have reported they get a little tickle when touching some panels on their roof. I would not like this situation.
The issue with that is you won't know you have an earth fault until someone climbs up a metal ladder sitting in a puddle, to clean their solar panels, and gets a 400VDC shock then they touch the frame. With everything earthed, the inverter can monitor for earth faults and give an alarm as soon as it detects a low resistance path between + or - DC and ground.
Just installed the 200a jk bms I bought through your link with aliexpress. Tried starting it with 9v positive to b- and negative to p- as per your other video. The light is blinking on bms but inverter and charge contoller does not turn on. Only getting 2.2 v on p- side??? What is going on?
I have mixed feelings on grounding solar panels or even the metal roofing. I understand that if a panel shorts out, you want the current going to ground so you don't get electricuted when servicing. However, when grounding, you effectively turn the solar panels and metal roof into a lightning rod.
Hi Andy, ich machs mal schnell auf deutsch, sorry, baue gerade meine Victron Anlage in der Garage... hab wenig Zeit. (3x MP II 48/5000 2x 450/100 und Fronius 10kW mit 22kWp Solar und 31kWh Speicher) Kann es sein, dass du diese Unterlegscheiben (washers) mit den Spitzen falschrum montierst (also mit der Öffnung Richtung Modul, nicht Richtung Halter ? ich denke, die sind so gedacht, dass du sie 50% unter die Klemme /Halter und 50% unter das Modul legen sollst, deshalb haben die auch die Aussparung für eine Schraube... nur so ne Idee... Deine Werte sind ja so schon Okay Gruss aus dem Odenwald Michael.
Hallo Michael, das dachte ich mir auch und hab das probiert. Das hat leider gar nicht funktioniert, denn die Klemme sitzt nur ganz am Ende auf der Schiene und nicht mit der ganzen Flaeche. Am Ende hat sie nochmal so einen kleinen Vorsprung und nut dieser hat mit der Schiene Kontakt. Das ist so gemacht, das der Haltewinkel eine gewisse Hebelwirkung auf das Panel ausuebt. Ich denke, diese Erdungscheiben sind universal einsetzbar und je nach verwendetem System muss man sie unterschiedlich benutzen.
Did not appear to be a problem however I am concerned the large loop area of the wire and return path act as an antenna that can pick up radio waves, inducing current into the loop, and corrupt the resistance measurement that is actually measuring voltage and computing resistance as R=V/I. If the meter is a constant current source it may not be aware of any externally induced current. The external current should be AC and might be ignored by a DC measurement.
With a Lightning Protective system install in the solar system will you bond the Grounding of the solar to the Lightning Protective system ground together? or it should be separated?
In most of the Asian country complying their local codes, DC earthing should be separated from AC earthing. At least 3m apart. Lightning must not be bonded with any AC/DC earthing. This all I am talking about within one premises. I see BS and probably NEC recommends common earthing. Could you please address this issue.
Der Rahmen von den Panels muss nur in bestimmten Fällen geerdet werden. In meinem Fall muss ich das nicht. Keine Blitzableiter und flach auf Satteldach montiert.
By grounding the panels you are ,in a sense, raising the ground up to your your roof..if your idea is to remove static from the roof then break the ground with a diode to ground so you are not making the roof a lightning rod…or you could just put in a light switch to turn on before you go on the roof to remove the static…as we all know about magnetism and dc power, opposites attract and likes repel…if the roof is grounded always it will attract lightning….if it instead had a positive charge, or a static charge it would repel lightning…best idea is to put the switch to ground the roof before you go up then off when no one is on the roof…why do you think rvs or any vehicle with solar panels are so much less likely to be lightning struck?..
Andy, Just had a thought while watching your vid about faulty victron controller. I notice you have victron inverters... so do i and i had a bad experience not long after installation. Lots of sparks and smoke. The MP2 has a large opening in the bottom and a gecko got in. The boards dont have conformal coating and gecko got fried. I was told it was my fault because I have geckos. It was eventually replaced under warranty when I pointed out that it was installed by their installer to their specifications into an environment that has geckos. The replacement had a screen fitted by the supplier that keeps the geckos out. As you are in Queensland, you should think about screening out the geckos.
Hi Ron I heard more than once from this problem with geckos and lizards I live in Philippines now and you see them anytime ,I start soon with a offgrid build here and use Victron also Can you tell us how’s look the screen or can you make a photo of it Thanks Marc
@@marcvandaele1878 I dont think I can add photos, but its made of pressed plate steel maybe 1mm, with holes/slots pressed into it, maybe 2mm width. It it bent to conform to the shape of the bottom opening and held in place by the bottom cover. Also, ensure the cable penetrations are secure for i suspect a gecko crawled up inside a conduit at on stage - a generous squeeze of silicone solved that. I also put a generous silicone bead along the bottom of the board between the board and back of the case to stop anything that does get in, from squeezing between the high voltage terminals and case ground.
Messfehler durch Störspannungen oder Strömen im Erdreich von benachbarten Spannungsquellen mit den Frequenzen 16 2/3Hz, 50Hz, 60Hz und 400Hz werden ausgeschaltet, indem Messfrequenzen ungleich dem ganzzahligen Vielfachen der Netzfrequenz verwendet werden. Einige Messgeräte haben mehrere Messfrequenzen, die abhängig von den vorkommenden Störungen automatisch ausgewählt werden.
Some time ago, in another vídeo, about one battery cycle, I saw in one victron manual, that victron considers one cycle when: the SOC is below 65% and go above 90%. In 3 monthes, i have only one cycle. :) Only reach 65% one time. Bye.
Doesn't real;ly matter in the grand scheme of things. Lightning takes ALL paths of resistance. We arent dealing with 240 or even 500volts here, we are dealing with lightning at 1 million volts + and when things get that high it doesnt really matter how much resistance your ground path has. If it did then lightning would always goto earth ground and never destroy anything inside a grounded home during a strike.
I am just thinking blindly.... Is there a modern solution to detect thunderstorm so that it can shut off the whole system to avoid any loss apart from the earthing system..... Come on the electronics world..... Where are you ?
sir in all my installation I measure the voltage dc between positive end of the string and earth bar and. Then negative end of the string with the earth bar , the voltage will start with a high value like 300v DC and slowly come down to around 100v and stops there around 90 to 100v and. Doesn’t go below that what does that mean , is that still 100v is leaking through the. Earth body and we r loosing actual current , please help me to get the answer as I’m searching for a long. Time and keep doing installations but this pattern is always there
Hi from Germany!
Just a heads up from an electrician, who did close to nothing else but safety measuring electric gear and buildings:
During measuring of the resistance of the grounding, you need to absolutely ensure the measuring current is at or above 200mA. In machine building they recommend even 10A straight. Yes, you read that right.
I don't believe your tester there does provide that amount of energy for that, so these testers you referred to do have their eligibility...
Interesting. I guess they want to make sure the resistance is not all concentrated on one spot that will heat up if the current is flowing.
One of Andy's bench supplies could do it. 1 ohm, 1A = 1V drop. 1 ohm, 10A = 10V drop ... yah, a 5A or 10A CC/CV supply could do it. They can usually go up to 30-40V or so. That would be good for up to around 3 ohms. But he would have to make sure that the supply is isolated from the mains, otherwise there is an alternative path to ground through the neutral-ground bond.
The voltage drop can be used to calculate the approximate resistance as well as double-check that the ground path is solid. And one can look at the junctions (wire meets screw, etc)... bad connections will have excessive heating.
@@junkerzn7312 Sorry, but I deem that a little bit dangerous. Professional testing gear does have some safety built in and that's one part of why that is so expensive (I'm talking about the real stuff, not the cheaper gear Andy referred to). The other part is brand naming. Only a little part of the price to pay is the actual hardware, the R+D or the marketing...
@@wiedapp Mmmm. Lets just say that alarm bells don't go off in my head when we're talking about < 50V and current that is already mostly flowing through a low-impedance path. I think it is low risk on both accounts. But I'll grant you that a dedicated tester will be safer since the bench supply more or less runs the current continuously while switched on and a dedicated tester does not.
But again.... cost. And if you are testing junction temperatures at the screw terminals and so forth, you have to run a continuous current anyway.
-Matt
Agreed.
In the high voltage industry we normally use 100A current to test contact resistance, and the test is referred to as a ductor test. Check out the Megger MOM2. Very clever piece of equipment that fires up to 200A through to give you a reading in the microohm range, and it is surprising small and light.
Greetings from Poland!
superbe vidéo, j'adore l'extension pour le tests sur le toit de la terre 😅
Hi Andy Im from Adelaide SA according to NECA and Clean Energy Australia plus AS 3000 placing them washers under the panels is not enough. Thats only mechanical connection you need to have what is called electrical connection for that you need main Earth to the railing and from that Earth you need individual Earth to the each panel. That ruling came out December 21 also the Earth measuring is taken from the main Earth stake that way you know all the Earthing is correct. Love your videos keep up the good work kind regards from South Australia.
I wish you lot of fun a lot of sun :) from Czech Republic. I am glad to see you channel with Victron product. Nice. Please don't stop :)
Thanks, Petr! 😃
if you extend both wires of one probe the tester will measure the resistance from probe to probe without the cable resistance, thats the reason for the sense cables😉 greetings from sunny hot germany 😎
I know that but I cannot take the wires off the probe.
@@OffGridGarageAustralia But you could make an extension cable for the 4-pin connector - but that requires ordering the fitting connector.
For followers interested in low resistance measurement they can lookup Kelvin Connection.
Great find you already had perfect tooling for this with the resistance meter.
Probably not optimal but gives me a good understanding of the resistance and the quality of the job we have done.
Andy, next time you get bit or feel a cold coming on use a cue stick cotton swab soaked in hydrogen peroxide. Use it to clean your nasal passages if you feel a cold coming on and your ears for an earache works great.
Very interesting... didn't know the anodized coating was also electrically insulating.
Me neither 🤷♂️
Thank you Andy, this ia really illustrative
Thank you.
Wow, thank you for this platinum Information.
Glad it was helpful!
FYI In the States the grounding washers are called 'WEEB" wahsers. WEEB stands for "Washer, Electrical Equipment Bonding"
Thank you, I came across this term but this explains it now.
Sehr schön.. 2 Videos an einem Abend.. Und ich hab kein Netz auf meinem Parkplatz 😥 hab aber viele StandBilder von dir...😋
Ja Erdung is wichtig. Ich hatte Modulklemmen wo die höllische unterlegScheibe gleich dran war... Nach nem jahr hatte ich nochmal gemessen. Und die Ergebnisse waren fast identisch...schön das du es allen mal ganz genau zeigst. Jedoch wundert mich die konstanten 1, 77
Trotz der langen Wege.. Ich hatte Unterschiede zwischen ersten und letzten Modul.. Bei dir is ja alles quasi gleich.. Bisl komisch 😎
Das ist ja alles mite dem Dach und dem anderen Metall verbunden. Und wie genau das Geraet misst, weiss ich nicht, aber es war bisher kein Ausreisser dabei, der mir ueber 2Ohm angexeigt hat.
You could use your power supply set at 10 volts and 100 milliamps (on ground to test) and read the volt drop from point to point accurately as ohms with your meter.
Excellent Demonstration Andy.Well Done!. I'm thinking your internal resistance meter will give you a better idea of ground continuity than a low voltage OHM function on a Digital Multi-meter.
As your system relatively low current I say your tests should be adequate.
I've got a bit of experience installing and testing grounding systems and grids for large power generation and distribution systems, and actual ground impedance in a multi megawatt AC generation system in operation can be quite different than measuring static resistance, but in your case I Say good enough. In fact, I'm not really sure if a commercial High resolution earth tester would tell you anything meaningful if you used one. I've used industrial MEGGER units like the DET2 that could give you indications that your system is unacceptable if you did not understand what is was you were doing. Sort of like measuring resistance on a 100m of 18 gauge wire with 50amps seeing a lot of resistance. Conversely, you could measure 'good' ground connections for a 200 amp service with 5ma using a DVM, and read .5 OHM, and conclude you have a ground, but would it hold up to a 50amp or 200 amp fault to ground, or a 1,000 to 10,000 amp surge to ground without blowing or melting a ground connection apart?
Safe and adequate grounding is about proper sizing and ability to handle shorts to ground that a system is capable of producing without creating voltages on any part of exposed metal that people could come in contact with when things go "Bang', 'Buzz', or 'Sizzle'
Good Stuff Andy, Thanks!
Btw, I just found this instruction on using the MEGGER DET2 for those are wondering about the use and purpose for using a professional earth tester:
ua-cam.com/video/wXbtvJF-zyA/v-deo.html
Thanks Andy 👍
OK Rudolph, I believe you.
Just wondering and not taking into account the regulations, WHY and WHAT is the purpose to ground the metal parts of a solar array?
There is not a a hard connection possible between the metal parts and the live of the grid. It might even improve the change of lighting strikes when the metal parts are grounded….. regards
All metal parts need to be grounded for electrical safety. This has nothing to do with lightning protection. Two different things.
If you have an inverter in your system, you have 230V (or 120V) somewhere. There is always the chance that something goes wrong...
OK, this could possibly be made up "theoretically". However, the aluminum frame of a solar panel is completely insulated from the cells with their connections, see the double insulated symbol on the panel. So if a live phase ends up on the DC cables from the panel, there is still no reason to ground the frame. Moreover, there are solar arrays for off-grid use (as the off-grid garage) and there is no determined live (phase) at all anymore. Moreover, grounding the frame (on the roof) gives a risk-increasing aspect with regard to lightning strikes.
nice discussion and keep up your most appreciated channel!
@@OffGridGarageAustralia It's not possible, your home is earthed, and power returns to it's source...you are worried about AC power, not DC, so it returns to it's source which is already grounded/earthed. It accomplishes nothing, but do it if it makes you feel better about "safety".. Describe the scenario where grounding a PV system has any "safety". A ground rod is 25ohms with respect to earth and at 120Vac can carry 5amps tops, where does the rest go? It's rhetorical, we know where the rest goes....and it's not to earth.
@@iamblaineful On a different channel, one person earth grounded his solar panels which was about 1k worth. Lightning struck close by and fried everything he had. AC has to be grounded in order to complete the circuit. You are absolutely correct that there is no need to earth ground DC whatsoever otherwise they will have a Lightning Magnet.
Clip leads also create problems when trying to measure small resistances. And inductance too.... if any of the wiring is coiled, that creates problems as well. And fingers as well... all sorts of problems. What I do is use WAGOs to connect the probes to the wiring to get a really solid contact. Or a screw-down if connecting to rail or conduit. The thin wire will cause problems too.... I usually have thousands of feet of ethernet cable sitting around so I just use an ethernet cable and strip and bind all 8 wires together (or in two sets of 4 wires each which allows me to loop it if I want to), to make a long cable. And I zero the meter out on the cable. WAGOs are great for gluing everything together so the measurements can be made hands-off.
A non-precision meter also tends to be inaccurate when trying to measure small resistances, particularly if you have to do a relative measurement from a non-zero 'zero point'. That's one of the few cases where I pull out the 8845A for 6.5 digit accuracy. But it will probably work reasonable well for what you are testing as long as the resistance isn't in the gutter. Just make sure you have solid connections and its hands-free... no holding wires OR probes with your fingers while taking a measurement.
Continuity... like Continential... Contin - new - ity (at least in American English). Hahaha.... reminds me of a very embarassing moment once when I was doing a lecture on RPN expression parsing 30 years ago and I said "Urinary" instead of "Unary". I don't think its possible for anyone to top that one!
-Matt
But even with a 8845A, the problem still remains, the need of a decent test current to do such measurements.
So tools like e.g. the MPK-257 from Sourcetronic or the Megger DLRO10HD are the better choice.
@@Frost4 Well, its a lot of money for a tool most of us almost never need to use. The 8845A does have a 4-wire measurement mode, but it is true that it is only 100mA. Still, it does have it. I think it is acceptable to do the resistance measurement and the current validation separately. As long as the results are relatively close to each other. The current validation can easily be done with a relatively uncalibrated bench supply.
Next time you've been bitten use vinegar directly on the spot it will directly neutralize the bite and the itching and swallowing will stops directly, works also for other insect bites, even red ants
I hate vinegar but will keep this in mind. Thank you.
"Press HOLD to enable the ZR function to measure internal resistance as low as 0.30-0.50 milliohms. The ZR function measures below 5 ohms, and the internal resistance is more accurate."
I have been told that the best way to use those special washers is to have them on alternative corners of the panels, which works really well when you have a string of panels and can share a washer between two adjacent panels.
They won't be long enough to span across the gab between two panels, Trev.
@@OffGridGarageAustralia Ah okay, I guess it only works when you are butting the panels up against each other.
Should you turn the grounding washer around. That way the clamp and panel are grounded. I see the washers appear to be cut out possibly to allow for the mounting bolt? Also, looks like your meter does have a "Zero" function. Great videos!
A step in the right direction. Do you get much lightning there? Thanks for sharing
No, only rarely. But with the climate changing rapidly now, who knows.
This is grounding though, not lightning protection.
You need some pointy probes to get past the anodized coating. Very interesting....almost no conductivity with that coating when you install the panels. You really do need the funky washers or equivalent new version racking clamps that can pierce the coating.
Yes, I didn't know that either and wasn't aware that it is actually isolating.
wow didn't realize the Anodized aluminum is basically insulated aluminum. Although, if that is the case what is the reason to ground it? A stray wire comes into contact with the Anodized alum frame rail and...nothing happens since the coating prevents the power from the wire transmitting to the aluminum interior? unless there is a heavy scratch or high enough voltage to bridge?
I used Galv unistrut for my installation, although I can't say I did it this way deliberatly to avoid anodized aluminums' insulation effect, nor did I deliberately drill the PV frames for mounting to the strut to ensure good ground, it just worked out that way LOL. I also never bothered to test the resistance from Ground to the rails/PV panels (until today!) since it seemed "obvious" that it should all be 'good' - thanks for sharing Andy, now I know I am all good instead of assuming it. Interesting from the comments the various regulations across jurisdictions for the grounding requirements. Like Arc-fault and Disconnect requirements, these are all different depending upon where you live it seems, perhaps we will see a convergence over the next decade of code requirements for PV everywhere.
I didn't know this either as I never tested it but all my panels weren't grounded. I have now ordered more of these washers.
Rudolph the Rednose Rainfrog
Hi great content, dose all this grounding effect the bi metal insulation between different metals! And Increase corrosion! Which is why the rail feet are insulated in the first place.
Thank you, Lauri. Is that why? I thought the rubber is to prevent water from coming in...
Dissimilar metals can generate a small voltage which has the POTENTIAL to corrupt the resistance measurement.
It really is fascinating to see my posts randomly never appear to the public, but I can still see them if logged on. I guess someone somewhere just doesn't like me asking questions and making valid observations :)
If you have links or certain words in your comment, UA-cam will delete them.
Couldn you use the 4 point probes method (Kelvin Probe, 4T sensing) of the yr1035+ for the extension line ? That means 2 wires for the extension line and the resistance of the cable will be cancelled out.
The tester has 4 wires. I just could not take them off the probes.
@@OffGridGarageAustralia Yes 2 wires to the "on site" probe on the roof remain unchanged. The other two wires of the other probe will be extended and stay isolated from each other until the main ground bar, where they both are connected the ground bar independently.
Most rail end and mid clamps these days are "bonding". They'll have something sharp to pierce the coating on it.
Never seen them so far. It would make sense though.
@@OffGridGarageAustralia maybe it's just the rail systems that are common in the US that have them. All the major ones that I looked at used bonding clamps.
What’s the different between earth washes vs the grounding cable you use last time?
Are they interchangeable? Looks like you need both..
The earth washers connect the single solar panels to the rail. And you connect the ground cable to the rails. Otherwise you would need to ground every single panel.
how would you solve it, if there would be potential risk from lightning/flash impact? Is better to have grounding connected or is better to have it connected to lightning rod/conductor/termination (i don't know exact name of it).
Grounding is for electrical safety.
Lightning Protection is for... well lightning protection
These are two different things. LP is nothing for a DIY job any more and needs proper installation and testing.
Earthing is to stop you being electrocuted if there is a short to the metal. You'll feel it but it will take the path of least resitance down to earth so won't kill you. You have effectively created a lightening rod so need a lightening arrestor in your combiner box.
be kind, please tell me, I have an electric bike, in cells, lifepo4, 16 s, there is a big difference in current, what is being charged, what is being discharged, now I can't decide which, good, active, load balancer to buy ,
Here in the uk the earthling requirements for solar have changed several times...from nothing to more and more. I personally dont see the need to ground the panels..that's why we have earth free zones, however you do have a metal building so its probably harder to keep it earth free than to earth every thing.😑
Not earthing at all is dangerous. Especially with solar and high DC voltages. Some people have reported they get a little tickle when touching some panels on their roof. I would not like this situation.
The issue with that is you won't know you have an earth fault until someone climbs up a metal ladder sitting in a puddle, to clean their solar panels, and gets a 400VDC shock then they touch the frame.
With everything earthed, the inverter can monitor for earth faults and give an alarm as soon as it detects a low resistance path between + or - DC and ground.
@@cods41 ... which I think, is monitored by the new RS 450/100 MPPT chargers from Victron.. I have 2 of them... :)
@@mw9271 Yes, I think most modern solar inverters have earth fault monitoring. I think it is a requirement under the AS/NZS standards.
No earth pit impedance test?
Just installed the 200a jk bms I bought through your link with aliexpress. Tried starting it with 9v positive to b- and negative to p- as per your other video. The light is blinking on bms but inverter and charge contoller does not turn on. Only getting 2.2 v on p- side??? What is going on?
Does the app connect?
@@OffGridGarageAustralia No it does not connect or show up. I think the caps in my inverter spiked the current when I turned on the bms frying it.
I have mixed feelings on grounding solar panels or even the metal roofing. I understand that if a panel shorts out, you want the current going to ground so you don't get electricuted when servicing. However, when grounding, you effectively turn the solar panels and metal roof into a lightning rod.
Hi Andy, ich machs mal schnell auf deutsch, sorry, baue gerade meine Victron Anlage in der Garage... hab wenig Zeit.
(3x MP II 48/5000 2x 450/100 und Fronius 10kW mit 22kWp Solar und 31kWh Speicher)
Kann es sein, dass du diese Unterlegscheiben (washers) mit den Spitzen falschrum montierst (also mit der Öffnung Richtung Modul, nicht Richtung Halter ?
ich denke, die sind so gedacht, dass du sie 50% unter die Klemme /Halter und 50% unter das Modul legen sollst, deshalb haben die auch die Aussparung für eine Schraube... nur so ne Idee...
Deine Werte sind ja so schon Okay
Gruss aus dem Odenwald
Michael.
Hallo Michael, das dachte ich mir auch und hab das probiert. Das hat leider gar nicht funktioniert, denn die Klemme sitzt nur ganz am Ende auf der Schiene und nicht mit der ganzen Flaeche. Am Ende hat sie nochmal so einen kleinen Vorsprung und nut dieser hat mit der Schiene Kontakt. Das ist so gemacht, das der Haltewinkel eine gewisse Hebelwirkung auf das Panel ausuebt.
Ich denke, diese Erdungscheiben sind universal einsetzbar und je nach verwendetem System muss man sie unterschiedlich benutzen.
Did not appear to be a problem however I am concerned the large loop area of the wire and return path act as an antenna that can pick up radio waves, inducing current into the loop, and corrupt the resistance measurement that is actually measuring voltage and computing resistance as R=V/I. If the meter is a constant current source it may not be aware of any externally induced current. The external current should be AC and might be ignored by a DC measurement.
I don't always ground my solar panels...but when I do I wear my comfortable SLIPPERS... Hahahahahahahahahahahahaha
Heya have to see what the regulation tels me here in Holland but that's a easy way of testing yes
With a Lightning Protective system install in the solar system will you bond the Grounding of the solar to the Lightning Protective system ground together? or it should be separated?
To make what work?
In most of the Asian country complying their local codes, DC earthing should be separated from AC earthing. At least 3m apart. Lightning must not be bonded with any AC/DC earthing. This all I am talking about within one premises. I see BS and probably NEC recommends common earthing. Could you please address this issue.
Contin-yooitty
Der Rahmen von den Panels muss nur in bestimmten Fällen geerdet werden. In meinem Fall muss ich das nicht. Keine Blitzableiter und flach auf Satteldach montiert.
A few more Mossie attacks on the old nose Andy, and people might start calling it the "off-Grid Clown Garage"
By grounding the panels you are ,in a sense, raising the ground up to your your roof..if your idea is to remove static from the roof then break the ground with a diode to ground so you are not making the roof a lightning rod…or you could just put in a light switch to turn on before you go on the roof to remove the static…as we all know about magnetism and dc power, opposites attract and likes repel…if the roof is grounded always it will attract lightning….if it instead had a positive charge, or a static charge it would repel lightning…best idea is to put the switch to ground the roof before you go up then off when no one is on the roof…why do you think rvs or any vehicle with solar panels are so much less likely to be lightning struck?..
Is earthing really a word in Ozz or is that your Germanish? It rolls up my toe nails reading it 🙂
This is a word everywhere, not just down here. Is it earth or ground?
Andy, Just had a thought while watching your vid about faulty victron controller. I notice you have victron inverters... so do i and i had a bad experience not long after installation. Lots of sparks and smoke. The MP2 has a large opening in the bottom and a gecko got in. The boards dont have conformal coating and gecko got fried.
I was told it was my fault because I have geckos. It was eventually replaced under warranty when I pointed out that it was installed by their installer to their specifications into an environment that has geckos.
The replacement had a screen fitted by the supplier that keeps the geckos out.
As you are in Queensland, you should think about screening out the geckos.
Hi Ron
I heard more than once from this problem with geckos and lizards
I live in Philippines now and you see them anytime
,I start soon with a offgrid build here and use Victron also
Can you tell us how’s look the screen or can you make a photo of it
Thanks
Marc
@@marcvandaele1878 I dont think I can add photos, but its made of pressed plate steel maybe 1mm, with holes/slots pressed into it, maybe 2mm width. It it bent to conform to the shape of the bottom opening and held in place by the bottom cover.
Also, ensure the cable penetrations are secure for i suspect a gecko crawled up inside a conduit at on stage - a generous squeeze of silicone solved that.
I also put a generous silicone bead along the bottom of the board between the board and back of the case to stop anything that does get in, from squeezing between the high voltage terminals and case ground.
Das geht aber so nicht mit der Messung ... Messstrom und Spannung zu niedrig ... AC nicht DC
Messfehler durch Störspannungen oder Strömen im Erdreich von benachbarten Spannungsquellen mit den Frequenzen 16 2/3Hz, 50Hz, 60Hz und 400Hz werden ausgeschaltet, indem Messfrequenzen ungleich dem ganzzahligen Vielfachen der Netzfrequenz verwendet werden. Einige Messgeräte haben mehrere Messfrequenzen, die abhängig von den vorkommenden Störungen automatisch ausgewählt werden.
no, that is the moskitoo beer you did not wanna tell us.
Some time ago, in another vídeo, about one battery cycle, I saw in one victron manual, that victron considers one cycle when: the SOC is below 65% and go above 90%. In 3 monthes, i have only one cycle. :) Only reach 65% one time. Bye.
5th!
You soon will have 100 amps outside!
I will have 140A outside when all the panels are installed. But only in summertime.
Thanks Andy now all I notice is your nose lol
Don't!
CONTI - NU - ITY 🤣
there is a 'd' missing 😂
@@OffGridGarageAustralia you know us English don’t embrace that kind of thing 🤭😂🤣
@@Timmy_DC I thought by now it is hot enough over there for the extra 'd' 😁
Doesn't real;ly matter in the grand scheme of things. Lightning takes ALL paths of resistance. We arent dealing with 240 or even 500volts here, we are dealing with lightning at 1 million volts + and when things get that high it doesnt really matter how much resistance your ground path has. If it did then lightning would always goto earth ground and never destroy anything inside a grounded home during a strike.
I am just thinking blindly.... Is there a modern solution to detect thunderstorm so that it can shut off the whole system to avoid any loss apart from the earthing system..... Come on the electronics world..... Where are you ?
This method is for grounding, not lightning protection. Two different things.
Rudolph the red nosed reindeer ... sorry der musste jetzt raus
1 lol
UA-cam kick me off your channel 😒
You're here!?
sir in all my installation I measure the voltage dc between positive end of the string and earth bar and. Then negative end of the string with the earth bar , the voltage will start with a high value like 300v DC and slowly come down to around 100v and stops there around 90 to 100v and. Doesn’t go below that what does that mean , is that still 100v is leaking through the. Earth body and we r loosing actual current , please help me to get the answer as I’m searching for a long. Time and keep doing installations but this pattern is always there