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diy solar

electrical help please

chrisw5

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I'm in the process for planning out my DIY install. I have 400 amp service at my house. See below for a view of how the power enters my house. I have two 200 amp service lines coming in that terminate in a utility room inside the house with two breaker panels. Instead of creating a new critical load panel, I am thinking about disconnecting one of the 200 amp service lines and moving a breaker or two around to make one of the breaker panels (Panel 2) my critical load panel. Can you all please take a look and see if I'm on the right track with this? Am I overlooking anything with this approach? I intend to also install a 100amp transfer switch in the event I would ever need to take the Sol-Ark offline.
meter.jpg
schematic.jpg
 
I'm in the process for planning out my DIY install. I have 400 amp service at my house. See below for a view of how the power enters my house. I have two 200 amp service lines coming in that terminate in a utility room inside the house with two breaker panels. Instead of creating a new critical load panel, I am thinking about disconnecting one of the 200 amp service lines and moving a breaker or two around to make one of the breaker panels (Panel 2) my critical load panel. Can you all please take a look and see if I'm on the right track with this? Am I overlooking anything with this approach? I intend to also install a 100amp transfer switch in the event I would ever need to take the Sol-Ark offline.
View attachment 59286
View attachment 59287
That seems like a reasonable approach. The only potential issue I see is overpowering panel 1. The easiest way to check is to add up the actual current of all the devices and see if it is over 200A. If it is under 200A, you are good to go. If it is over 200A you may still be ok. In household system design there are formulas that allow for the fact that not everything is on at once and the result allows for smaller panels. Unfortunately, I can't seem to find a link to a good calculator so you might have to do some research. However, in the calculators, certain types of high current items are counted as always on so it may not give you much relief.

Note: The reason I even bring this up is that I was surprised that you have a 400A feed. My main breaker box is only 200A and that is more than I need.... but I have gas hot water, Gas stove, Gas Cloths dryer, no pool and no hot tub. You have a lot more high current loads than I do.

BTW: You want to make sure you are OK with the Electric Dryer on Panel 2. Will the Solark handle that? It will certainly drain your batteries quickly.
 
That seems like a reasonable approach. The only potential issue I see is overpowering panel 1. The easiest way to check is to add up the actual current of all the devices and see if it is over 200A. If it is under 200A, you are good to go. If it is over 200A you may still be ok. In household system design there are formulas that allow for the fact that not everything is on at once and the result allows for smaller panels. Unfortunately, I can't seem to find a link to a good calculator so you might have to do some research. However, in the calculators, certain types of high current items are counted as always on so it may not give you much relief.

Note: The reason I even bring this up is that I was surprised that you have a 400A feed. My main breaker box is only 200A and that is more than I need.... but I have gas hot water, Gas stove, Gas Cloths dryer, no pool and no hot tub. You have a lot more high current loads than I do.

BTW: You want to make sure you are OK with the Electric Dryer on Panel 2. Will the Solark handle that? It will certainly drain your batteries quickly.
the diagram seems a little confusing. I think i understand what he intends to do. he intends to power panel2 with the solark(and batteries) but the way the diagram is drawn, it's connected to panel1.

@op The transfer switch needs to sit between panel2's grid feed and panel 2. Then, the solark will feed the transfer switch on its ups/secondary input.
 
That seems like a reasonable approach. The only potential issue I see is overpowering panel 1. The easiest way to check is to add up the actual current of all the devices and see if it is over 200A. If it is under 200A, you are good to go. If it is over 200A you may still be ok. In household system design there are formulas that allow for the fact that not everything is on at once and the result allows for smaller panels. Unfortunately, I can't seem to find a link to a good calculator so you might have to do some research. However, in the calculators, certain types of high current items are counted as always on so it may not give you much relief.

Note: The reason I even bring this up is that I was surprised that you have a 400A feed. My main breaker box is only 200A and that is more than I need.... but I have gas hot water, Gas stove, Gas Cloths dryer, no pool and no hot tub. You have a lot more high current loads than I do.

BTW: You want to make sure you are OK with the Electric Dryer on Panel 2. Will the Solark handle that? It will certainly drain your batteries quickly.
Thanks FilterGuy. I actually plan to pull the breaker out for the electric dryer and move it over to Panel 1. Definitely not a critical load. :) If household energy goes over 200A what would happen? Main breaker trip?
 
the diagram seems a little confusing. I think i understand what he intends to do. he intends to power panel2 with the solark(and batteries) but the way the diagram is drawn, it's connected to panel1.

@op The transfer switch needs to sit between panel2's grid feed and panel 2. Then, the solark will feed the transfer switch on its ups/secondary input.


interesting..... I read the diagram differently. The OP seems to be doing something very similar to what I am considering with a SolArk. The manual transfer switch is only there for maintenance. In normal operation the automatic transfer switch in the solark will be decideing between grid and inverter. You can think of it like this:

1628470994610.png

However, the OP wants to be able to isolate the solark and still drive panel 2 from the grid, so he added the manual transfer switch.

Edit: Modified schematic to avoid crossing lines (easier to read/understand)

1628530322657.png
 
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the diagram seems a little confusing. I think i understand what he intends to do. he intends to power panel2 with the solark(and batteries) but the way the diagram is drawn, it's connected to panel1.

@op The transfer switch needs to sit between panel2's grid feed and panel 2. Then, the solark will feed the transfer switch on its ups/secondary input.

interesting..... I read the diagram differently. The OP seems to be doing something very similar to what I am considering with a SolArk. The manual transfer switch is only there for maintenance. In normal operation the automatic transfer switch in the solark will be decideing between grid and inverter. You can think of it like this:

View attachment 59331

However, the OP wants to be able to isolate the solark and still drive panel 2 from the grid, so he added the manual transfer switch.

View attachment 59332
Correct. Sorry, I should have included arrows... Kudos for the photoshop correction!
 
If household energy goes over 200A what would happen? Main breaker trip?
If the load on panel 1 goes over 200A, the main breaker in panel 1 will pop and the Transfer switch in the Solark will switch to battery mode.

Notice that in normall operation *all* of your power will be going through the 200A breaker of Panel 1. It seems unlikely that the original electrition put in two 200A boxes if only one would do it.... and that is why I advise figuring out if one 200A panel is enough for your total load.
 
interesting..... I read the diagram differently. The OP seems to be doing something very similar to what I am considering with a SolArk. The manual transfer switch is only there for maintenance. In normal operation the automatic transfer switch in the solark will be decideing between grid and inverter. You can think of it like this:

View attachment 59331

However, the OP wants to be able to isolate the solark and still drive panel 2 from the grid, so he added the manual transfer switch.

View attachment 59332
I see. I didnt know the solark had a transfer switch, as well. My mistake.
It still confuses me, though. I don't understand the desire to feed the solark from panel1.
Shouldn't it go inline with the leg that feeds panel2? You can still add a transfer switch to bypass(and isolate) the solark.
 
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I see. I didnt know the solark had a transfer switch, as well. My mistake.
It still confuses me, though. I don't understand the desire to feed the solark from panel1.
Shouldn't it go inline with the leg that feeds panel2? You can still add a transfer switch to bypass(and isolate) the solark.
Yup. The SolArk 6K and SolArk 12k are some pretty impressive pieces of kit. (And rather pricey)
  • Inverter-charger
  • 240V Split Phase
  • Auto Transfer Switch
  • Multiple MPP solar inputs
  • Battery free or with batteries
 
Yup. The SolArk 6K and SolArk 12k are some pretty impressive pieces of kit. (And rather pricey)
  • Inverter-charger
  • 240V Split Phase
  • Auto Transfer Switch
  • Multiple MPP solar inputs
  • Battery free or with batteries
So why feed it from panel1?
 
The OP has two breaker panels, both driven from the grid
The standard Solark setup has a critical load panel that is fed by the solark. This panel is separate from the non-critical load panel.
The OP wants to rewire the system to make one of the panels grid fed (non critical load panel) and one SolArk driven Critical load panel
Meanwhile, The SolArk needs to be driven from grid power.

That leaves two choices for feeding the Solark:
1) Feed the SolArk (and the Manual transfer switch) from Panel 1.
2) Feed the SolArk (and the Manual transfer switch) directly from the grid.

Either will work, but #2 probably requires installing a 3rd small panel to deal with the breakers that need to be between the grid and the solark & Manual Transfer Switch.

If panel 1 can handle all the load, then having panel 1 feed the SolArk is the easiest solution. If Panel 1 can not handle all the load, one possible mitigation is to feed the Solark from the grid.
 
The OP has two breaker panels, both driven from the grid
The standard Solark setup has a critical load panel that is fed by the solark. This panel is separate from the non-critical load panel.
The OP wants to rewire the system to make one of the panels grid fed (non critical load panel) and one SolArk driven Critical load panel
Meanwhile, The SolArk needs to be driven from grid power.

That leaves two choices for feeding the Solark:
1) Feed the SolArk (and the Manual transfer switch) from Panel 1.
2) Feed the SolArk (and the Manual transfer switch) directly from the grid.

Either will work, but #2 probably requires installing a 3rd small panel to deal with the breakers that need to be between the grid and the solark & Manual Transfer Switch.

If panel 1 can handle all the load, then having panel 1 feed the SolArk is the easiest solution. If Panel 1 can not handle all the load, one possible mitigation is to feed the Solark from the grid.
I see now. If I would have stepped through hooking things up in my mind, I may have caught that. It would be a mess attempting to do it any other way. Thanks for your explanation!
 
I see now. If I would have stepped through hooking things up in my mind, I may have caught that. It would be a mess attempting to do it any other way. Thanks for your explanation!
If I had not done some previous design work involving the SolArc I would probably have been scratching my head as well.
 
BTW:

1) The breakers in the diagram will be dual/240Volt breakers.
2) you should consider feeding the critical loads panel through a 60A breaker.
* If there is an existing 200A main on the pannel it is too big for anything but a disconnect.​
* There really should be a main breaker between the SolArk and the rest of the circuits.​
3) Be careful about creating ground loops or Neutral loops
Edit: removed the following line:
4) If the neutral on the Solark is just pass through from the input to the output, the neutral from the Solark to the manual transfer switch in the diagram below below should be removed.

EDIT: Corrected Neutral in following diagram.

1628622344319.png
 
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Thanks for the suggestions. Concerning item 4) above:
4) If the neutral on the Solark is just pass through from the input to the output, the neutral from the Solark to the manual transfer switch in the diagram below should be removed.

I am a bit confused at what you mean as pass through from input to output. Since the neutrals have a bus on the transfer switch could that cause a neutral loop? My original plan was to run neutral and ground directly from Panel 1 to Panel 2, bypassing the transfer switch.

ts1.jpg
 
I am a bit confused at what you mean as pass through from input to output.
What I am calling 'pass through' is If the neutral line of the input is connected directly to the neutral line of the output. So, as an example, the manual transfer switch in the picture you provided has a neutral that is 'pass through'

Edit: After looking at the Solark Manual more closely, I concluded there should be no neutral from the Sol-Arc to the Transfer switch. I have corrected the diagram in my previous post.


BTW: you have a typo on the switch picture. The Solark Output Phase X in the lower right should probably be Phase Y.

Grounding is a bit hard to advise without knowing more about what is already set up for your system.

My *guess* is that the earth ground ties into your system at the 400A service entrance on the outside of your house. I am also guessing there is a neutral-Ground Bond at the service entrance as well. From the main service entrance, it looks like you have a separate 200A feed to each of the breaker panels inside. These feeds probably each have a ground wire to a ground bus in the breaker panel. I am also guessing that there is *no* connection between Neutral and Ground in either of the breaker boxes. (These guesses are based on what the most likely thing the electrician did to meet code)

Assuming the above is correct, you will notice that from any point along the ground wire, there is one and only one path back to the earth ground point at the service entrance. That means there is no ground loops.... and you want to keep it that way. One way to do that would be to leave the existing ground connection on both panels but not have ground from panel one or the Solark go to panel 2. This would be a bit weird because ground is not being routed with the power. (This may not even be to code)

The other way to rout ground is to completely disconnect the ground from the 400A Feed to Panel 2 and feed ground from panel 1 to panel 2 (This is what I tried to show in my diagram above)

The reason I show the ground coming from Panel 1 to the transfer switch and not from the solark is
1) doing both would create a ground loop and
2) this allows the solark to be totally removed without disturbing the ground path to Panel 2).

Your transfer switch does not appear to have connections for ground wires.... but it is a metal box so the box should be grounded. Your ground wire should be 6AWG between the two boxes, so traditional wire nuts for connecting the ground inside the transfer switch are probably not viable. You may want to purchase a grounding busbar to mount inside the switch box. (Just make sure the mount grounds the box as well)
 
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In the SolArk manual I see this:

1628621174008.png
In this picture the middle box is a combination load center and transfer switch. For the OPs plan this is broken out into two separate boxes.

Notice that the neutral in the Sol-Ark is tied to the Grid (non-critical) load center. Furthermore the neutral for the load *also* comes from the load center. So.... in my original diagram I showed a neutral from the Solark to the transfer switch and ultimatly to the critical loads distribution box... but it should not be there. (I should have known better than to do the drawing by memory.) Here is an updated version of the drawing with everything corrected. (I will also update the previous post)

1628621742407.png

Notice that I show the neutral and ground still going from Panel 1 to the transfer switch and then to Panel 2. It could also be done like this:
Edit: corrected following diagram:

1628622771406.png
(The remaining ground wire to the transfer switch is to tie the metal box to ground.)

The choice between the two comes down to whatever is easiest. If you are using conduits, it may be easier to rout the neutral and ground through the transfer switch rather than adding a conduit from panel 1 to panel 2.
 
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In the SolArk manual I see this:

View attachment 59567
In this picture the middle box is a combination load center and transfer switch. For the OPs plan this is broken out into two separate boxes.

Notice that the neutral in the Sol-Ark is tied to the Grid (non-critical) load center. Furthermore the neutral for the load *also* comes from the load center. So.... in my original diagram I showed a neutral from the Solark to the transfer switch and ultimatly to the critical loads distribution box... but it should not be there. (I should have known better than to do the drawing by memory.) Here is an updated version of the drawing with everything corrected. (I will also update the previous post)

View attachment 59571

Notice that I show the neutral and ground still going from Panel 1 to the transfer switch and then to Panel 2. It could also be done like this:
Edit: corrected following diagram:

View attachment 59577
(The remaining ground wire to the transfer switch is to tie the metal box to ground.)

The choice between the two comes down to whatever is easiest. If you are using conduits, it may be easier to rout the neutral and ground through the transfer switch rather than adding a conduit from panel 1 to panel 2.
Question: Don’t you needneutral feeding the panel from the inverter? Without it how will 120 volt circuits work?
 
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