Beginning installation of Schneider XW Pro/EG4ll batteries V1/MPPT 100A 600V OFF-GRID only questions

[BentleyJ]

If I am using 1 string of panels that equal about 329V (8 panels) in series, would a breaker that goes to 240V still work?

No

But the instructions show a second 125A breaker that goes between the pv coming in from the array to the charge controller. #2 on the diagram page (3rd photo)

I'm confused. Why would you need a 125A breaker between the PV array and the charge controller? Its high voltage but low amperage. What Is the Isc of those 8 panels in series.

 

[SniperX]

No

I'm confused. Why would you need a 125A breaker between the PV array and the charge controller? Its high voltage but low amperage. What Is the Isc of those 8 panels in series.

Was just going by the wiring diagram (2nd photo #2 step) Could only process one step at a time so now looking at the pv end. The Isc is 11.61A

 

[SniperX]

Schneider offers those breakers. I thought they even included part numbers in the manual.

I'm it sure if this is the right one, this might be wider.

Schneider Electric 865-DCBRK-125 125 Amp DC Breaker

Schneider Electric 865-DCBRK-125 125 Amp DC Breaker

www.solar-electric.com

I am trying to connect the pv array positive (coming from outside) to the 125A breaker they want installed and then the other end goes out to the pv + on the charge controller. The one you have listed is for the battery connections which I already have so I just need a second one? It is only 125v and that is what I am wondering since I have over 300V coming in on that pv wire...

 

[BentleyJ]

So that is Short Circuit current, lets assume worst case scenario the array can produce 11.6A x 392V = 4,547Watts which translates to 81A of battery charging current at 56V. What you need is a breaker rated for 400V and 12A. 15A may be the closest size.

In this case I'm not sure the mini PDP is helping. Typically a 2 pole breaker is used for the PV array to charge controller since neither + or - PV wire is grounded so either or both could have potential compared to ground.

 

[SniperX]

I would suggest that you power your load panel directly from the inverter out terminals. Hook the generator into AC2 (Gen input). The Schneider can switch between inverter and AC2 fast enough that it is like you don't lose power. Also, you can run the generator into your loads panel in "Pass Through" mode. In addition, you will be able to charge your batteries from the generator. As far as the Grid wires you should probable just hook them up between the PDP breaker and the inverter. Yes, they won't actually carry and current for now. I seem to recall that not all A / C paths include a neutral, so make sure that if AC1 has a neutral wire from the inverter to the PDP, that you actually hook that wire up. I think all the neutrals are tied together in the inverters, so as long as there is a neutral path from the Load panel to the PDP and from the PDP to the Inverter, you should be OK. It just seems more fool proof to go ahead and wire up everything as designed so far as the PDP to inverter connections.

What I have done is install a Generator Inlet box on the outside wall, but you could put that box where ever you want. It's just that there is no reason to not take advantage of the built in generator switching the inverter provides. Think about it. If you wire this as you are thinking, once your batteries are low you will need to run the Gen 24*7. If you wire it to the inverter, you can charge up the batteries for a couple of hours. Far less noise and fuel.

Rereading things a year later, do you have photos of your set-up when your were wiring it up? I would like to see what you are describing? Appreciate it.

 

[BentleyJ]

Just looked through the mini PDP installation guide, section B lists only 1 breaker for the PV input side. Its a 160V, 60A DC breaker. Nothing listed at all for the Conext 80/600 or 100/600 charge controller.

Looks like you may need to look into using a generic breaker which will be mounted outside the mini PDP. Although a simple disconnect switch would probably be sufficient just so the mini PDP termianls could be deenergized if needed.

 

[SniperX]

So that is Short Circuit current, lets assume worst case scenario the array can produce 11.6A x 392V = 4,547Watts which translates to 81A of battery charging current at 56V. What you need is a breaker rated for 400V and 12A. 15A may be the closest size.

In this case I'm not sure the mini PDP is helping. Typically a 2 pole breaker is used for the PV array to charge controller since neither + or - PV wire is grounded so either or both could have potential compared to ground.

So that is Short Circuit current, lets assume worst case scenario the array can produce 11.6A x 392V = 4,547Watts which translates to 81A of battery charging current at 56V. What you need is a breaker rated for 400V and 12A. 15A may be the closest size.

In this case I'm not sure the mini PDP is helping. Typically a 2 pole breaker is used for the PV array to charge controller since neither + or - PV wire is grounded so either or both could have potential compared to ground.

Just realized that there is a fuse outside in the midnite solar box, although the fuse may be too big. I originally thought I would have 2 strings in parallel, so they sent a 32A fuse. So, I need to get a 15A fuse instead. My brain said it should be in the pdp like the diagram, but the string will go through the midnite solar box first where this fuse is and then go into the charge controller, so same thing. My brain... Would this work then? https://www.currentconnected.com/pr...eBXcdNcqMnwJ7p_ERTMTfXkExl5k7zgxoCNHMQAvD_BwE

Separately, so since neither the + or - pv wire is grounded is this what is called a floating array?

 

[SniperX]

Just realized that that breaker is outside in the midnite solar box, although the breaker may be too big. I originally thought I would have 2 strings in parallel, so they sent a 32A breaker. So, I need to get a 15A breaker instead. My brain said it should be in the pdp like the diagram, but the string will go through the midnite solar box first where this fuse is and then go into the charge controller, so same thing. My brain... Would this work then? https://www.currentconnected.com/pr...eBXcdNcqMnwJ7p_ERTMTfXkExl5k7zgxoCNHMQAvD_BwE

Just looked through the mini PDP installation guide, section B lists only 1 breaker for the PV input side. Its a 160V, 60A DC breaker. Nothing listed at all for the Conext 80/600 or 100/600 charge controller.

Looks like you may need to look into using a generic breaker which will be mounted outside the mini PDP. Although a simple disconnect switch would probably be sufficient just so the mini PDP termianls could be deenergized if needed.

I have this (4th and 5th picture) before it comes into the building on the outside. NO fusing/breakers, just a square D disconnect. I have a midnite solar combiner box that will be at the array (2nd and 3rd photo) . I was going to have 2p strings but now only going with 8 panels in series. Could I use the midnite solar combiner box and order 15A fuses instead of the supplied 32A (1st photo)

 

[BentleyJ]

Yes, that fuse holder will work as it has the necessary ratings

EDIT: The 15A fuse will be fine. Note that the fuse holder is NOT a suitable means of disconnect since it says DO NOT SWITCH UNDER LOAD.

However, the Square D disconnect does have DC ratings listed under the HP table so should be acceptable.

 

[SniperX]

Yes, that fuse holder will work as it has the necessary ratings

EDIT: The 15A fuse will be fine. Note that the fuse holder is NOT a suitable means of disconnect since it says DO NOT SWITCH UNDER LOAD.

However, the Square D disconnect does have DC ratings listed under the HP table so should be acceptable.

Should I just go ahead and get this and call it a day? This would serve as a disconnect inside somewhere near the PDP/charge controller since the mini fuses cannot disconnect under load.

MidNite Solar MNEPV Circuit Breakers – 600Vdc 15A~20A

The MidNite MNEPV 600V Breaker is good for high-voltage systems that need a two-pole breaker. With two versions, the 15A and 20A, these are ideal for any 600VDC system. Specifications: Width: 1 inch (26mm) Environmental Rating: Type 1 (Indoor) Listed for US & Canada Din Rail Mount 2-pole

www.currentconnected.com

 

[BentleyJ]

Yes, the 2 pole breaker would be an excellent solution.

 

[SniperX]

Yes, the 2 pole breaker would be an excellent solution.

Yes, the 2 pole breaker would be an excellent solution.

You are the absolute best! Thank you so much for your help.

ONE last question: there are 2 fuse holders on the MPPT charge controller. One for pv + if the pv+ is grounded. One for pv - if pv- is grounded and you leave both fuses out for an ungrounded (floating array) a few discussions back you mentioned ungrounded so both the neg. And pos. Pv would go through the double pole circuit breaker I am getting. Should I then leave both fuses out?

 

[SniperX]

Yes, that fuse holder will work as it has the necessary ratings

EDIT: The 15A fuse will be fine. Note that the fuse holder is NOT a suitable means of disconnect since it says DO NOT SWITCH UNDER LOAD.

However, the Square D disconnect does have DC ratings listed under the HP table so should be acceptable.

I just checked their fuses they sent with that Midnite solar combiner box fuse holder. The holder is rated for 32A but the fuse is 20A. Can I just use the 20A fuse with the holder as planned and not change that for out at the array? I know you said really 12A and 15A would work, and 15A is 1.25 times 12. Would it be ok to go with the 20A fuse or should I buy 2 15A fuses and put them in the fuse holder?

 

[BentleyJ]

The solar panel frames, racking, metalic enclosures, metalic conduit etc. are considered "Equipment Grounds" and are always required to be tied to Earth.

The other type of ground is a "System Ground" which is referring to having Earth Ground tied to one of the active, current carrying conductors. Example would be the Neutral-Ground bond so often mentioned here. Most all modern inverters do not require or recommend grounding either of the PV wires or battery wires. So in this particular example, it is considered an Ungrounded System, System being the operative word.

EDIT: Sorry didn't even answer the question. Yes, leave the fuses out of the Charge Controller if neither the + or - PV wire is attached to earth ground.

Lastly, With solar there is a tendancy to think of DC, both the PV panels and the battery, in terms of automotive. This is a completely different circumstance where the Negative side of the battery is connected to the chassis which forms one of the conductive paths. Using the term "ground" in this sense is misleading because it is NOT Earth Ground. It is simply that by convention, the negative terminal is considered 0 potential compared to positive terminal. This is actualy not true, a battery (cell) has an anode and cathode each with its unique half cell potential that when combined equals the total voltage of the cell.

 

[BentleyJ]

If you are planning on installing the 2 pole breaker then just use the 20A fuse as a conductor to complete the circuit.

 

[wheisenburg]

Rereading things a year later, do you have photos of your set-up when your were wiring it up? I would like to see what you are describing? Appreciate it.

In looking at this, it looks like the questions are specific to a mini-PDP panel. I used the full PDP panel.

When I wrote this I believe the issue had to do with what to do with the grid wires from the PDP to the inverter if you were not planning to actually connect the system to the grid. I believe my advice was go ahead and hook them up anyway. They wouldn't actually do anything, but why leave them hanging around loose? It looks like there were some other questions about how to hook up the charge controllers and what circuit breakers to use.

I pretty much followed to installation manual exactly for my two inverter setup.

The only unusual thing I did was to add a contactor to provide mutual exclusion between the generator inputs and the AC coupled solar. AC coupled solar is connected to the Inverter Out. The generator is connected to the AC2 Input. There is a contactor sitting inline on both of these connections. The contactor control coil is hooked to the incoming generator feed. If there is no voltage on incoming feed the contactor will not activate. The AC coupled solar feeds through the normally closed contacts and the generator is on the normally open contacts. It cannot feed through to the inverter. When the Generator is on, the incoming voltage is apply to the contactor coil. The will activate the contactor.

When the contactor is activated the AC Coupled solar will be disconnected from the Inverter Out. The generator will be connected to the AC2 Input.

The reason this is done is that Micro Inverters are designed to push as much current as possible unto the system they synchronize with. When this system is the grid, the unused power will back feed into the grid which is fine. If the micro inverters synchronize with a generator, they will attempt to back feed unused power into the generator. So Schneider says that this switching contactor is absolutely required to avoid damage to the generators and microinverters.

AC coupled solar solar can work off grid in a pinch, but the fact is that it is really not the best way to do an off grid system. I wanted to add emergency backup to my grid tied micro inverters. I have put together a system that works, but it took some manufacturer updates and a lot of work to get a system I feel can properly manage the battery charging speed and level.

I have some photos of that work here:

https://diysolarforum.com/threads/building-a-pv-shedding-controller-for-ac-coupled-solar.80666/

 

[SniperX]

In looking at this, it looks like the questions are specific to a mini-PDP panel. I used the full PDP panel.

When I wrote this I believe the issue had to do with what to do with the grid wires from the PDP to the inverter if you were not planning to actually connect the system to the grid. I believe my advice was go ahead and hook them up anyway. They wouldn't actually do anything, but why leave them hanging around loose? It looks like there were some other questions about how to hook up the charge controllers and what circuit breakers to use.

I pretty much followed to installation manual exactly for my two inverter setup.

The only unusual thing I did was to add a contactor to provide mutual exclusion between the generator inputs and the AC coupled solar. AC coupled solar is connected to the Inverter Out. The generator is connected to the AC2 Input. There is a contactor sitting inline on both of these connections. The contactor control coil is hooked to the incoming generator feed. If there is no voltage on incoming feed the contactor will not activate. The AC coupled solar feeds through the normally closed contacts and the generator is on the normally open contacts. It cannot feed through to the inverter. When the Generator is on, the incoming voltage is apply to the contactor coil. The will activate the contactor.

When the contactor is activated the AC Coupled solar will be disconnected from the Inverter Out. The generator will be connected to the AC2 Input.

The reason this is done is that Micro Inverters are designed to push as much current as possible unto the system they synchronize with. When this system is the grid, the unused power will back feed into the grid which is fine. If the micro inverters synchronize with a generator, they will attempt to back feed unused power into the generator. So Schneider says that this switching contactor is absolutely required to avoid damage to the generators and microinverters.

AC coupled solar solar can work off grid in a pinch, but the fact is that it is really not the best way to do an off grid system. I wanted to add emergency backup to my grid tied micro inverters. I have put together a system that works, but it took some manufacturer updates and a lot of work to get a system I feel can properly manage the battery charging speed and level.

I have some photos of that work here:

https://diysolarforum.com/threads/building-a-pv-shedding-controller-for-ac-coupled-solar.80666/

I will have to take a look. Thanks for the information.

 

[SniperX]

A year later, lol.
I am getting ready to install my panels. Long process.
Now, I am working on the outside near the array.
I have a Square D cut-off switch on the right. The positive pv wire from the panels in series and the negative pv wire from the panels will go straight into the cut-off switch on the top portion. Then, they will go out of the cut-off switch into the midnite solar fused breaker. Then out to the cut-off switch on the side of the building.

SEVERAL QUESTIONS:
I found this on AltE's videos I was watching. They say the negative wire should be white? Do I wrap the black negative wire with white tape? (photo 11)
Does my negative battery cable coming from the batteries going to the inverter need to be taped white too? Right now, positive is red and negative is black.

The liquid tight going between the two boxes should have a weep hole for condensation. Should I just attach a T fitting of some type to achieve this? (1st, 2nd photo and the rule in 3rd photo)

Does it look like I wired this correctly?
I did tape the negative wires white in the midnite solar combiner box but thought to ask if this was correct before I do it in the square D cut-off switch which has not been taped white (yet). (photos 4-6)

I haven't put the panels on so those wires coming from the panels will enter the top of the square D cut-off switch through the weather head. I know I should not have come in from the top, but I will put a meyer's hub there to weatherproof it. 8 panels wired in series.

The 7th photo shows where the midnite solar wiring will go from the array back to that cut-off switch which then goes through the wall and into the chase way and into the metal pipe out to the CC. (photo 12)

The last two photos are so you can see how those go back to the power shed.

Anything else I should know or change?
THANKS! @BentleyJ @GXMnow @400bird @hwy17
@timselectric

 

[hwy17]

(As always, don't take my word alone for anything)

I found this on AltE's videos I was watching. They say the negative wire should be white?

Weird. Sounds like more negative grounded array stuff. White = grounded conductor. I only use black red and green for my PV wiring.

The liquid tight going between the two boxes should have a weep hole for condensation.

I've never heard of the NEC calling for that. The water in the conduit keeps the wires from drying out! But if you really wanted to you could put an outdoor box on the post so the conduit goes disconnect > box > combiner with the box at the lowest spot and then the box will act as a weep.

Does it look like I wired this correctly?

Everything looks correct to me. I've never used a combiner box though. Whenever I see them I get the feeling they come from the negative grounding area because of the way they treat the negative block like a neutral block. But your wiring looks correct for how I imagine a combiner box should be used with a modern floating array.

 

[SniperX]

(As always, don't take my word alone for anything)

Weird. Sounds like more negative grounded array stuff. White = grounded conductor. I only use black red and green for my PV wiring.

I've never heard of the NEC calling for that. The water in the conduit keeps the wires from drying out! But if you really wanted to you could put an outdoor box on the post so the conduit goes disconnect > box > combiner with the box at the lowest spot and then the box will act as a weep.

Everything looks correct to me. I've never used a combiner box though. Whenever I see them I get the feeling they come from the negative grounding area because of the way they treat the negative block like a neutral block. But your wiring looks correct for how I imagine a combiner box should be used with a modern floating array.

The video I watched from AltE is quite old and you are probably right. I forgot all about it until I saw a guy say the same thing on a 2 year old video. This is why I am asking. Everyone knows black is negative.

Only thinking about the weep because of the mike holt thing but not sure if it applies to solar due to it being DC. I will go back and tag Tim and see what he says. Thanks for answering my questions!

 

[hwy17]

Only thinking about the weep because of the mike holt thing but not sure if it applies to solar due to it being DC.

Oh I haven't seen that, I'd take his advice on anything. But I know that my 150ft underground run of conduit to my array sits there full of water for most of the year.

 

[SniperX]

Finally installed my panels! This is what we got installed so far. Waiting for the bright mounts to come back in stock. So happy to have this done!
Just have to install my cut-off switch and then connect the wires on the panels, bring to the box and flip the switches.
Do I commission the Charge controller (Schneider 100 600) before I power on the panels or do I do it when I turn everything on? (the two little panels on the ground are 12v for my dometic electric coolers. I use these to charge a SOK 206A lithium battery) I am completely off-grid.

 

[BentleyJ]

You should be able to set up the user menu on the charge controller if the Xanbus cable is connected and powering up the circuit board. Doesn't seem like the panels would need to connected. If that were the case, none of the settings could be viewed or changed at night.

 

[SniperX]

@timselectric Can you check this for me? I think I may have wired the FUSE holder wrong on the midnite solar combiner box.
The panels PV wire comes in to the large Square D disconnect box on the right. Then it goes out through the liquid ream toward the left into the midnite solar combiner box. Should the PV + array (input) wire go into the BOTTOM of the fuse holder and then the Positive wire for PV output go into the top of the fuse holder which then goes out toward the charge controller? I think I have it backwards in photo 1.

 

[Offthewall]

@timselectric Can you check this for me? I think I may have wired the FUSE holder wrong on the midnite solar combiner box.
The panels PV wire comes in to the large Square D disconnect box on the right. Then it goes out through the liquid ream toward the left into the midnite solar combiner box. Should the PV + array (input) wire go into the BOTTOM of the fuse holder and then the Positive wire for PV output go into the top of the fuse holder which then goes out toward the charge controller? I think I have it backwards in photo 1.

Doesnt matter. Its a fuse so power is just passing through it.