Multiple grounding rods for solar panel install and electrical devices?

[timselectric]

Let's make sure we are not confusing people. Ground rod at the array required by code and inspection in San Diego County, CA where array is located about 200 feet from the home. In fact, all 3 arrays required by code to be grounded. Period, end of discussion on that.

Incorrect.
Not required by code.
Maybe it was your inspector that wanted it.

 

[Nonlin]

Use at least -15C.



VOC is the max voltage that can be supplied to the SCC before magic smoke appears.

The operating range is the voltage the MPPT will operate. This can be a problem as your MPPT is rated for max operating voltage of 115V. With 3S, you are over that voltage. It might work or it might not. It might read the voltage and not turn on.

I'm not a fan of running anything electrical at limits. I see enough electrical failures in my line of work, I don't need to fix my own stuff.



Correct.



Spend money once and be done with it. If you plan on any expansion down the road, be sure to size something like an EGC for any added expansion.



Bump your conduit size up. Have you ran your wire size and number thru a conduit fill calculator? 6 AWG is pretty big. If you want to add another string with 2 more wires in 1"SCH80 PVC conduit will exceed conduit fill according to NEC plus might be a bitch to pull.

If it was me, for what the 6AWG will cost, I'd go buy a higher voltage MPPT, use 10AWG and minimum of 1.25" conduit. Using 1" SCH 80 PVC will allow eleven 10AWG wires down the road. But 1.25" is much easier to pull. (plus up to twenty one 10AWG wires will meet NEC)

6AWG will cost twice what 10AWG will cost. I come up with $234 for 200 feet of 6AWG THHN/THWN plus you need a larger ground if you start paralleling strings. 200 feet of 10AWG THHN/THWN $102, however you would do better buying a 500 foot roll of 10AWG for $140 and a roll of red electrical tape or red heatshrink. That way you can run a few extra wires in the conduit for expansion.

You do have another choice and that is to combine strings right before the SCC. This allows running 10AWG for the 80 feet with less voltage drop and power loss. With just 2 strings you won't need the combiner box, just a disconnect such as the IMO, then combine both strings at the MPPT. No fuses/breakers needed but I would recommend a SPD on each string somewhere. This is your best option if you want to combine strings.

EGC to the battery case

Ok thanks for all this extra clarity. Also note I had a miss type of 1/2 inch conduit its actually 3/4 inch a chart stated for 6AWG max wires I can is 4 so I think I'm good with the 3, +,-, Ground.

I do not plan on expanding this system, its just to dip my feet into solar. We may move, and this isn't a total pain to move, 6 panels vs 6 + panels for a larger system. I totally hear you on volts over amps for the smaller cables and cheaper cost there. I did foolishly ignore that consideration when I was aiming for a cheaper inverter. But hey, at least if the magic smokes take this inverter it was only 650 (which still sounds like it will be very rare if ever that it happens in my location) but if the temp coefficient is too much for the MPPT and that trips it up then I may be forced to sell the inverter and get one that will work for my system and weather but that also seems like a wild card at the moment but one of those things where it seems like we can cross that bridge if we do in fact get there.

I just ordered me some 40 foot direct burial wire from https://www.wireandcableyourway.com/6-awg-xlp-use-2-rhh-rhw-2-building-wire

The rest from amazon. That should set me up for success assuming i install everything correctly.

 

[timselectric]

Not required by NEC.

Just because your AHJ is ill informed or ignorant does not change the NEC.

Didn't see your post, before I replied.
But they probably need to be told several times, anyway.

 

[stevenforti]

does the fact that my house has a ground already create a ground loop when I install one for this system I am building? Keeping in mind they will be completely independent?

I thought I heard this guy say something to that effect. I believe he's the owner here?

 

[stevenforti]

Something I still remain confused with. In my drawing I didn't have any breaker to trip when it comes to my solar array so if it's actually the breaker tripping which saves me (or anyone else) from burning to a crisp how is that going to work in the diagram I drew?

this is so confusing

 

[timselectric]

does the fact that my house has a ground already create a ground loop when I install one for this system I am building? Keeping in mind they will be completely independent?

No
Because they are not connected in any way.

Something I still remain confused with. In my drawing I didn't have any breaker to trip when it comes to my solar array so if it's actually the breaker tripping which saves me (or anyone else) from burning to a crisp how is that going to work in the diagram I drew?

this is so confusing

The fault current won't be coming from the solar panels. It will be coming from the AC side. And trip those breakers to clear the fault.

 

[Nonlin]

No
Because they are not connected in any way.

The fault current won't be coming from the solar panels. It will be coming from the AC side. And trip those breakers to clear the fault.

What is a controlled and safe way to test that things are wired in a safe way so we know we did things right?

 

[gotbeans]

What is a controlled and safe way to test that things are wired in a safe way so we know we did things right?

I do continuity check on multimeter and attach 1 end to the.. say ground and the other to a long wire and walk around and poke it against things to see if anything is beeping that shouldn't
can do it with pos, neg, load, neutral and ground

 

[JRH]

I think the anxiety, vagueness and variables on the topic of grounding, may cause drinking..…..

J.

 

[timselectric]

What is a controlled and safe way to test that things are wired in a safe way so we know we did things right?

All things that are bonded together should read continuity between them.

 

[Zwy]

Didn't see your post, before I replied.
But they probably need to be told several times, anyway.

CA is it's own "little world" which adopts NEC with CA Additions to the code.

Another reason not to live there, you have government mandating things that contradict proven good practices.

It is possible San Diego County has the requirements mentioned. If you want to find out, of course you will pay for the CA code to look at it. It should be free to anyone wanting to read it so requirements that actually create issues could be questioned and corrected.

Nothing like living in "your own little heavy government handed world". It really is fascism at this point where big corporations work with government to control the population. NEM 3.0 is another example.

 

[hwy17]

.

 

[hwy17]

NEM 3.0 is another example.

As if NEM 1 and 2 weren't an entirely government creation? I don't think a private operator would've said "hey, let's come up with a rate to lose money on solar customers".

 

[Nonlin]

I found this. My inverter is mounted above this. I'm tempted to drill a hole there since there is already a cut out on the dry wall to get my PV wires from outside to inside my garage. IDK if its unsafe/unwise to run the PV wires through that. It looks like maybe a grounding rod? If so can I just ground directly to that or still wiser to ground via the electrical panels bus bar?

 

[timselectric]

I found this. My inverter is mounted above this. I'm tempted to drill a hole there since there is already a cut out on the dry wall to get my PV wires from outside to inside my garage. IDK if its unsafe/unwise to run the PV wires through that. It looks like maybe a grounding rod? If so can I just ground directly to that or still wiser to ground via the electrical panels bus bar?
View attachment 184329

That looks like an Ufer ground. (Concrete encased electrode)
It is part of the grounding system. So technically you could connect there.
If you do, I would verify that it is still connected. And has not been abandoned at some point in the past.
But I would rather connect at the main ground bar.

 

[Nonlin]

That looks like an Ufer ground. (Concrete encased electrode)
It is part of the grounding system. So technically you could connect there.
If you do, I would verify that it is still connected. And has not been abandoned at some point in the past.
But I would rather connect at the main ground bar.

And there's no issue making a hole there to route the outdoor PV wires into the inside via that area right?

 

[timselectric]

And there's no issue making a hole there to route the outdoor PV wires into the inside via that area right?

No, that's fine. If you can make it work.
The PV wires must be in metal conduit once they enter the building. PVC is fine on the outside.

 

[Zwy]

As if NEM 1 and 2 weren't an entirely government creation? I don't think a private operator would've said "hey, let's come up with a rate to lose money on solar customers".

This is how things went here in Timbuktu. Government mandated a certain percentage of power a utility sold had to come from renewables.

Utilities were caught flat footed, so they promoted wind and solar grid tie and even paid $0.10/Kwh for the power and pocketed $0.06/Kwh. As more renewable generation was built, the contracts were null and voided, the utilities didn't need the little guy and put them on net metering.

Meanwhile, the federal government decided to hand out money like candy to corporations that were starting up to create large wind farms and solar fields at an industrial level. It is a lucrative handout, one you and I won't get. Many politicians are filling their pockets with your tax money and whatever the government can print with these handouts. It's a free for all to enrich the connected. Now that we see renewables in industrial size have come online, the little guy is getting the shaft. Letters have gone out, now they are capping banked Kwh to force you to give up excess for free. No payout at true up either.

What's the future hold? If you don't have storage, you will get hosed like NEM 3.0.

 

[hwy17]

Government mandated a certain percentage of power a utility sold had to come from renewables.

That's usually where all the problems start, whichever way it goes wrong from there.

 

[Zwy]

That's usually where all the problems start, whichever way it goes wrong from there.

I think it was possibly good legislation as far as mandating a certain percentage come from renewables. If it hadn't been done, you would most likely not have the opportunity to go off grid with a solar system of any size with today's prices.

The issue is those who pull the levers of power saw this as an opportunity for financial gain and tend to promote legislation where they will gain at taxpayer expense. The major problem for the US economy and dollar is at some point the system will implode. So the government and Fed Reserve create bubbles in an attempt to keep the economy moving. Housing boom of early 2000's, shale oil and gas boom, and now the renewables boom. Those who have the opportunity and the power position themselves to profit off it.