SolArk Install Plan

Hedges

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I emailed the county about the setback from the ridge to the panels. They replied 36 inches.
It's probably better for me to have some space so I don't fall on the panels. 🤕
That is most recently adopted code.
Next revision of code is 18" on either side of ridge

Earlier code was 36" on both edges as well, walkways from eaves to ridge. Sometimes interpreted to include eaves, sometimes inside supporting wall.
Next revision of code is a walkway only on the side firemen would use to access the ridge (typically street side.)

But it doesn't look like you're trying to cover the whole roof, so may not care about more lenient rules coming.

What about that 15' x 43'? Is that a patio roof that would provide a huge amount of almost horizontal area? (except where shaded by trees.)

How about the South slope? I see one decent area, although partially shaded. The East/West arrays will produce considerably less in Winter.
 
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ArthurEld

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I think since I have panels on both sides of the ridge I have to have 36" But every time I ask the building dept a question they give the answer I don't want to hear.
18" does seem a little tight. Especially for anybody carrying something. It would really suck to trip and fall on to the panels.
My ridge vent caps are sticking up too.

I will fill some of the other spots with solar panels later. Being in Florida, I need a lot less electricity in winter.
 
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ArthurEld

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I bought the Reliance transfer switch and figured out how to connect it.

But SolArk is showing the connections differently in the picture below.

I emailed SolArk about the odd neutrals in the picture and this is their answer-

"If you look closely at the photo the neutral wire will be shared from the main service panel to the Sol-Ark directly therefore you will not need to connect the transfer switch neutral. However, please wire nut the neutral to terminate it."

So, this is my understanding-

The picture shows the ground and neutral are connected directly from the main panel to the SolArk.
The ground is connected from the main panel to the transfer switch.

The transfer switch is between the 2 hot wires only.

Any neutrals going in or out of the transfer switch should be terminated with a wire nut.



1608648338330.png
 

Hedges

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That works - neutral only connected to main panel and SolArk.
But I would like hots and neutral from main panel to pass through Reliance transfer switch enclosure on the way to SolArk, hots from main panel connected to transfer switch passing through same conduit or knockout, and hots from SolArk to transfer switch passing through same conduit or knockout.
(I don't want a circuit that goes out a hot and back through neutral to wrap around a piece of steel; that forms an electromagnet and inductor which is an AC impedance causing voltage drop. The losses of that magnetic "core" are turned into heat.
But if pre-wired you probably can't stuff the wires from main panel to SolArk inside the conduit.

"Any neutrals going in or out of the transfer switch should be terminated with a wire nut."
Are there any neutrals? I get the impression it is pre-stuffed with wire. If you ran romex into it then you'd have white neutrals. But I'd use 2+ground and use the neutral for switched hot, just like in house wiring going to a switch. Tape the ends, maybe, to distinguish from neutral.

The SolArk provided drawing is incomplete in that while it has a 240V connection from main panel to SolArk, it only has a 120V load connected to transfer switch. It doesn't show how to wire 240V branch circuits.

Have a photo of what's inside the transfer switch?
Does it come with wires dangling off all switches/breakers?
At first I assumed it had a pair of wires for feed from main panel, and a pair of wires for feed from generator/inverter. Internal busbars or wiring would fan both of those out to all selection switches.
However, based on the below it appears each selection switch is to be fed by an existing branch circuit breaker in main panel. Probably generator/inverter input is ganged across those selection switches so all are fed from your inverter.

"1. Find the two red and the two black wires marked A & B.
2. Turn off the double pole breaker for the well pump in the load
center.
3. Disconnect the two installed wires on the double pole breaker.
4. Cut the two red wires from Switches A & B at a length
convenient for them to reach to the double pole breaker. Strip
5/8” from the end of each red wire. Connect both red wires to
the double pole circuit breaker in place of the wires you just
removed from that breaker. It doesn’t matter in what order."

I would use a red and a black for the two phases from a breaker. Also for two phases to load. Transfer switch documentation has two blacks from breaker and two reds to load. Guess that is the color wires the pre-installed inside. Your actual branch circuit with existing Romex will either have red and black (plus white), or will have red and white, each connected to one hot phase if no neutral required.
 

ArthurEld

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That works - neutral only connected to main panel and SolArk.
But I would like hots and neutral from main panel to pass through Reliance transfer switch enclosure on the way to SolArk, hots from main panel connected to transfer switch passing through same conduit or knockout, and hots from SolArk to transfer switch passing through same conduit or knockout.
(I don't want a circuit that goes out a hot and back through neutral to wrap around a piece of steel; that forms an electromagnet and inductor which is an AC impedance causing voltage drop. The losses of that magnetic "core" are turned into heat.
But if pre-wired you probably can't stuff the wires from main panel to SolArk inside the conduit.

"Any neutrals going in or out of the transfer switch should be terminated with a wire nut."
Are there any neutrals? I get the impression it is pre-stuffed with wire. If you ran romex into it then you'd have white neutrals. But I'd use 2+ground and use the neutral for switched hot, just like in house wiring going to a switch. Tape the ends, maybe, to distinguish from neutral.
There is a loose neutral wire with the kit that is meant to go through the conduit to the main panel. I could just take it out.
If the generator plug / cable was used there would be a neutral wire or like you say romex would have one.
The SolArk provided drawing is incomplete in that while it has a 240V connection from main panel to SolArk, it only has a 120V load connected to transfer switch. It doesn't show how to wire 240V branch circuits.
My drawing is being updated to show both red and black wires for 240V going from the main panel to the transfer switch.
Have a photo of what's inside the transfer switch?
Does it come with wires dangling off all switches/breakers?
Each red and black wire is marked with a letter.
White wire isn't connected to anything
1608658088964.png
Lose wires for generator connection
1608658143251.png
Behind bridged 240V breaker
1608658208124.png
At first I assumed it had a pair of wires for feed from main panel, and a pair of wires for feed from generator/inverter. Internal busbars or wiring would fan both of those out to all selection switches.
However, based on the below it appears each selection switch is to be fed by an existing branch circuit breaker in main panel. Probably generator/inverter input is ganged across those selection switches so all are fed from your inverter.

"1. Find the two red and the two black wires marked A & B.
2. Turn off the double pole breaker for the well pump in the load
center.
3. Disconnect the two installed wires on the double pole breaker.
4. Cut the two red wires from Switches A & B at a length
convenient for them to reach to the double pole breaker. Strip
5/8” from the end of each red wire. Connect both red wires to
the double pole circuit breaker in place of the wires you just
removed from that breaker. It doesn’t matter in what order."

I would use a red and a black for the two phases from a breaker. Also for two phases to load. Transfer switch documentation has two blacks from breaker and two reds to load. Guess that is the color wires the pre-installed inside. Your actual branch circuit with existing Romex will either have red and black (plus white), or will have red and white, each connected to one hot phase if no neutral required.
The black wires are attached to the wires taken out of the main panel breakers with a wire nut. The red wires go into the main panel breakers.
 

Hedges

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I thought the selector switches picked either main panel or generator/inverter to feed the breaker.
Instead, it is a breaker panel for the inverter/generator. The selector switches connect load circuits to either these breakers or the ones from main panel.
That works.

I still would rather the loop of any circuit did not wrap around a piece of steel.
I heard of 600A wiring wrapped around a steel leg which heated the steel red hot.
When I saw a separate ground wire through steel conduit, I though it could cause higher impedance.
I tried sending several amps through wire in steel conduit (actually several turns of a conductor through the inside and back on the outside), but couldn't measure any increased impedance at 60 Hz vs. bare wire.
So may not really be an issue.
 

ArthurEld

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I could ask Solark why they don't want the neutral wire passing through the transfer switch. It might not hurt but Solark doesn't seem to think it is needed.

I am still not sure if I will keep this transfer switch. I am fairly sure I will need more than 6 circuits someday.
At the rate I work it could be years before I connect more than 6 circuits.

If the 10 circuit becomes available I will have to decide if I want to buy it.
My main panel has more then 10 circuits 5 of them are 240V.

There is also a 50A version of the transfer switch. This one is 30A.
 

Hedges

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Two of these transfer switches could be connected to main panel and SolArk.
Same functionality could be accomplished with a sub-panel of any size after the SolArk, and each protected load connected to a switch - SPDT for 120V load, DPDT for 240V load.
Make sure those switches are break-before-make!
Typically a switch has a small gap between contacts. I wanted a large gap and completely reliable switch isolating inverter output from grid. Knife switch would be best. Breakers intended to interrupt 10kA fault current should be pretty good, but reliable interlock between them is required.
An extension cord so protected loads panel is fed by either main panel or inverter makes an even larger airgap.

I've seen some 3PDT knife switches.
Square-D used two DPST or 3PST switches with interlock:


 

ArthurEld

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When I was looking around I saw a lot of ways to make a transfer switch.
And a lot of them are really cheap.

But I had my permit plan changed to use the Reliance so I am going to just stick with this one until I get through the permit process.
I think those instructions from Solark confused AltE too. But they're fixing up the plan for me.

This was $279. And it is really simple. And kind of nice.

If I need more circuits later I can deal with it then.
I need to get through this permit process and start using solar. I've been changing my mind back and forth for over 2 years.

Thanks again for all of your help Hedges.
 

ArthurEld

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I have this pass through box between the PV strings and the inverter.


Do I need a way to disconnect the PV strings? Or can I use the rapid shutdown if I need to disconnect?
 
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Hedges

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Pass-through box is where wires change from MC4 to THHN?
Doesn't parallel them. Maybe you have busbar, also fuses, whatever somewhere else if needed?

It is good to have a switch or breaker as disconnect. Rapid Shutdown might do that, but I prefer mechanical switches I can see rather than electronics to protect myself. Thought deleting rapid shutdown was the plan.
 

ArthurEld

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That pass through was added by AltE and it does switch wire types. I don't know if I need the pass through. It's $200.
I have string leval RSD. According to SolArk I don't have to use PV fuses since I only have 2 strings per MPPT.

I will look for a mechanical switch.
Thanks again Hedges.
 

Hedges

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For 2 strings you can use an MC4 "Y" connector to join them. The home run could be an MC cable, or you could change to THHN in such a pass through or an electrical box with wire nuts or other connectors. Or two MC pigtails could enter a box and join to a single wire. $200 is a lot for just a box and electrical connectors.

A combiner box, 3R for raintight, could take in the pigtails, put each through a breaker as disconnect, join with a busbar. That would give a disconnect located at the panels. Not sure if we're supposed to have a separate disconnect at the inverter.

I have either a disconnect switch attached to the inverter or nearby. After I shut off switches I walk out to the array and disconnect MC connectors. Then check with DMM at switches (or fuse holders) to confirm no voltage present.

Here's a type of switch I use. 3 poles, 600VDC, 30A


At the time I was supposed to open the positive but not the negative, so this supported 3 inverters. Code has changed.
Better to open both positive and negative. A ganged 2-pole breaker, DC rated (e.g. Midnight or Schneider) could do that. Probably rated 250 or 300 VDC when two poles used.
 

ArthurEld

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For 2 strings you can use an MC4 "Y" connector to join them. The home run could be an MC cable, or you could change to THHN in such a pass through or an electrical box with wire nuts or other connectors. Or two MC pigtails could enter a box and join to a single wire. $200 is a lot for just a box and electrical connectors.

A combiner box, 3R for raintight, could take in the pigtails, put each through a breaker as disconnect, join with a busbar. That would give a disconnect located at the panels. Not sure if we're supposed to have a separate disconnect at the inverter.

I have either a disconnect switch attached to the inverter or nearby. After I shut off switches I walk out to the array and disconnect MC connectors. Then check with DMM at switches (or fuse holders) to confirm no voltage present.
I am trying to understand how to work with PV while the sun is shining. I read one suggestion to throw blankets over the panels. But I never noticed installers doing that. I need to do some reading and I have four 100W panels to play with on my small system. That will happen soon.
Here's a type of switch I use. 3 poles, 600VDC, 30A

That switch seems good but it is for 3 circuits. I think I need 4 circuits. My strings need to stay separate because the SolArk has 4 inputs.
Am I thinking correctly?
At the time I was supposed to open the positive but not the negative, so this supported 3 inverters. Code has changed.
Better to open both positive and negative. A ganged 2-pole breaker, DC rated (e.g. Midnight or Schneider) could do that. Probably rated 250 or 300 VDC when two poles used.
I will have two 360V strings and two 240V strings. I think that is correct. 40 VOC x 9 panels = 360V
 

Hedges

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Shading panels with cardboard or something will lower current enough that nothing can be powered by them, but they may still produce sufficient voltage and current to electrocute you.

The way to work with PV while the sun is shining is to use the touch-safe MC connectors to isolate them while you work on other things, then mate them. Only mate/unmate with no current flowing.

By cutting an MC extension cable in half, you have a pair of pigtails. Connect them to a single panel for relatively safe voltage, measure with DMM to get polarity and color-code. Then do all your wiring with MC disconnected from PV.

I check Voc of each string by sticking DMM probes in the ends of the connectors (keep fingers off the exposed metal of probes.)

By "4 inputs" so you mean two MPPT inputs, 2 positive and 2 negative terminals?
In that case, ideally 4 poles of isolation, which that knife switch doesn't provide. Midnight 2-pole circuit breakers (if correct voltage) can isolate both ends of one string. Looks like theirs aren't high enough voltage, 150V per pole.


"I will have two 360V strings and two 240V strings. I think that is correct. 40 VOC x 9 panels = 360V"
Nominal, higher for max Voc spec of inverter.

I guess you would join two 360Voc in parallel (check voltage between the is about zero before connecting both ends of string), and two 240V in parallel.

Disconnect for your 360V (or higher) string is a bit more difficult. Midnight's breakers are 150V each, so would need 3 ganged in series.
Here's 4-ganged for up to 600V (also has remote trip)


Four touch-safe fuse holders would open both ends of two circuits. Not for switching under load.


These fuseholders are cheaper than normal:


Schneider has some products:



(not cheap!)
 

ArthurEld

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Shading panels with cardboard or something will lower current enough that nothing can be powered by them, but they may still produce sufficient voltage and current to electrocute you.

The way to work with PV while the sun is shining is to use the touch-safe MC connectors to isolate them while you work on other things, then mate them. Only mate/unmate with no current flowing.

By cutting an MC extension cable in half, you have a pair of pigtails. Connect them to a single panel for relatively safe voltage, measure with DMM to get polarity and color-code. Then do all your wiring with MC disconnected from PV.

I check Voc of each string by sticking DMM probes in the ends of the connectors (keep fingers off the exposed metal of probes.)
It is embarrassing how ignorant I am about this process. I have zero experience. It would be so much more difficult without your help.
By "4 inputs" so you mean two MPPT inputs, 2 positive and 2 negative terminals?
In that case, ideally 4 poles of isolation, which that knife switch doesn't provide. Midnight 2-pole circuit breakers (if correct voltage) can isolate both ends of one string. Looks like theirs aren't high enough voltage, 150V per pole.
The Solark 12K has 2 MPPTs and each MPPT has 4 inputs for 2 strings. This picture is accurate for # of wires -

1609672080205.png
"I will have two 360V strings and two 240V strings. I think that is correct. 40 VOC x 9 panels = 360V"
Nominal, higher for max Voc spec of inverter.

I guess you would join two 360Voc in parallel (check voltage between the is about zero before connecting both ends of string), and two 240V in parallel.
This is from the manual -
"Sol-Ark 12K has 2 separate pairs of solar panel inputs. (Dual MPPT)
Max PV input: 13,000W(+/- 5%) per system (6,500W per MPPT) PV = 500Voc Max
Max Isc input per MPPT: 25A (self-limiting to 20A @450Voc/300Vmp or 18A @ 500Voc/400Vmp)"
Disconnect for your 360V (or higher) string is a bit more difficult. Midnight's breakers are 150V each, so would need 3 ganged in series.
Here's 4-ganged for up to 600V (also has remote trip)


Four touch-safe fuse holders would open both ends of two circuits. Not for switching under load.


These fuseholders are cheaper than normal:


Schneider has some products:



(not cheap!)
I am going to have a bunch of disconnects and switches for PV, AC and batteries. This stuff is confusing. I want to set everything up so it looks good and makes sense. And everything will need labels in case someone else needs to use it and so it meets code requirements
.
Thanks again Hedges. Lucky for me I still have time to do more research. My system isn't going to match the permit paperwork exactly. I'm sure they are used to that and they will advise me if anything needs to be changed.
 
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Hedges

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OK, that's enough inputs for each PV string to go to its on pair of connections at the inverter.
Each MPPT input is to get two PV strings of same length so keep track of which is which. (long string parallel with short string would have voltage difference before connection, current flow when connected.)

Looks like RSD or "LSOB 600V Receiver" is the only disconnect in the design. Maybe that is good enough.

Various terminal blocks accomplish what's in that $200 box. Or just long MC pigtails. I used wire nuts in a waterproof conduit box.


 

ArthurEld

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I am not knowledgeable about wiring standards or codes which makes this difficult for me.
And my setup is pretty simple.
I have no idea what is standard but I like the big knife blade disconnects. And I could put it outside at about the same spot the passthrough box would go. Where the wires come down off the roof.
I don't think I need fuses or breakers though.

Edit: I don't know why but I am hesitant to use just RSD. But I will try to find out what is typical.

Found this too-
1609764343471.png
 
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