block diagram for sol-ark 15k vendor install

[prometheanfire]

Hi all,

I've been lurking around and trying to figure things out for getting a vendor to install something both maintainable and expandable for the future (may need more than one 15k if I get an electric car or electrify more things around the house). Trying to do things by the book in Indiana...

Here's what I came up with.



The main question I have is if that load-shedding panel needs an exterior cutoff switch?
I also don't think I need the 15A fuses (panels can handle 25A as the max series fuse rating).
I should be able to fully isolate the sol-ark inverter from solar, ac input and ac output in case of failure. Helps to isolate strings on the roof as well.

The battery bank would be post-vendor install, probably 30kwh eg4-ll in a cabinet, possibly expand in the future as well.

As for roof layout I've photos here https://photos.app.goo.gl/Ly2vPfnm6zzJe4YT9
The main roof area faces about 200°S. The main thing I wonder is if I need optimizers due to clipping caused by the eastern roof ridge?

I'm heavily considering doing it myself, maybe permits with https://ignergy.com/ or another vendor, not sure, would still need to sub out an electrician for at least the main breaker install.

 

[zanydroid]

load-shedding panel needs an exterior cutoff switch?

What do you mean by load shedding panel — critical loads panel? The emergency shutoff should power off that panel. I don’t believe jurisdictions typically require everything to shut off with one throw. This is the kind of thing that plan review will flag.

I should be able to fully isolate the sol-ark inverter from solar, ac input and ac output in case of failure. Helps to isolate strings on the roof as well.

Your fusing is overkill on the strings. 2p does not require fusing on individual substrings, there’s a special case allowance for it.

You sure 10AWG can carry the parallel current? You need to apply a 1.56 derate factor to account for continuous load and cloud lensing. 30/1.56= 19.2A max ISC on #10, which not enough for most 400W strings. I expect you will need #8 after the combiner.

The string calculation will be done for you by your plans service and then checked again during plans check.

The battery bank would be post-vendor install, probably 30kwh eg4-ll in a cabinet, possibly expand in the future as well.

Are these UL9540 listed with the SolArk?

If the PowerPro is listed you can consider that. It’s weather resistant and cheaper per kWh

 

[prometheanfire]

What do you mean by load shedding panel — critical loads panel? The emergency shutoff should power off that panel. I don’t believe jurisdictions typically require everything to shut off with one throw. This is the kind of thing that plan review will flag.

The Sol-Ark can operate what they call a "smart load panel" off of the generator input. This can be configured as a panel that drops loads when the grid drops out. I'm going to be moving the dryer, oven and installing a car charger on that port.

Your fusing is overkill on the strings. 2p does not require fusing on individual substrings, there’s a special case allowance for it.

You sure 10AWG can carry the parallel current? You need to apply a 1.56 derate factor to account for continuous load and cloud lensing. 30/1.56= 19.2A max ISC on #10, which not enough for most 400W strings. I expect you will need #8 after the combiner.

The string calculation will be done for you by your plans service and then checked again during plans check.

Ya, I thought the fusing was overkill too. As for wire gauge, the sol-ark runs 3 MPPTs with six inputs. I have 6 substrings, the only place the substrings are 'combined' is each MPPT input pair within the sol-ark, so no need for 8ga wire. There are a total of 6 dc-disconnect breakers.

Are these UL9540 listed with the SolArk?

If the PowerPro is listed you can consider that. It’s weather resistant and cheaper per kWh

If the EG4-LL, UL9540, yes, but not with the sol-ark. PowerPro is in consideration as well and should be UL9540 soon as well. From what I can tell Indiana code does not require listing with both the inverter and batteries paired. If I do need the pairing I'll go with the homegrid stack'd product.

 

[pvgirl]

The main question I have is if that load-shedding panel needs an exterior cutoff switch?

The emergency shutdown of the solark will take care of shutdowns on the outside of the house.
You will still need disconnects that can locked open on all inputs and outputs, the transfer switch will most likely take care of the load output, the 200amp main and loadshed panel main breakers will need to be provided with a hasp for locking in the off position or other lockable disconnect. Many types of breakers have cheaply available hasps that can be added to meet this requirement. Ref NEC 2020 706.15(A)

I also don't think I need the 15A fuses (panels can handle 25A as the max series fuse rating).
I should be able to fully isolate the sol-ark inverter from solar, ac input and ac output in case of failure. Helps to isolate strings on the roof as well.

No fuses are need on the solar input, in addition a separate PV disconnect switch is not required as this is built in to the sol-ark.
Since the PV panels will be installed on the house you will need rapid shutdown. Either an external transmitter or sol-ark's new built in one, and the appropriate modules at each solar panel. All PV wiring in the house must be in metal conduit and boxes, if you install a indoor PV disconnect it will need to be one in a metal enclosure. See NEC 2020 690.31(D) for more details. Also with each string on a separate run you most likely only need to use 12 AWG wire for each run. Don't forget to run a ground with your PV wires for bonding the panels and mounts. 6 awg is required where exposed on the roof, be sure to follow grounding requires of the mounting system you use.

The battery bank would be post-vendor install, probably 30kwh eg4-ll in a cabinet, possibly expand in the future as well.

Batteries UL9540 on their own or UL1973 listed should be ok at the moment. The Pytes E-Box 48100R is fully UL9540 listed for up 12 batteries with the sol-ark15k and is comparable in price to eg4 batteries.

As for roof layout I've photos here https://photos.app.goo.gl/Ly2vPfnm6zzJe4YT9
The main roof area faces about 200°S. The main thing I wonder is if I need optimizers due to clipping caused by the eastern roof ridge?

sol-ark does now offer their own optimizer and rsd modules. If you need them or their effect will depend on the layout of you panel strings.

I'm heavily considering doing it myself, maybe permits with https://ignergy.com/ or another vendor, not sure, would still need to sub out an electrician for at least the main breaker install.

DIY is possible for all this, including the main breaker. Having a professional do the main breaker and transfer switch wiring to your existing panel will help keep the time your house is without electricity to a minimum.

 

[zanydroid]

The Sol-Ark can operate what they call a "smart load panel" off of the generator input.

Ok so that’s the smart panel upsell within their ecosystem. Makes sense.

Having a professional do the main breaker and transfer switch wiring to your existing panel will help keep the time your house is without electricity to a minimum.

Main breaker will require coordination of power shutoff/restore with POCO unless you are OK with working live. The shutoff/restore procedure varies with each POCO, often requires coordination with the AHJ and the POCO to get it done quickly.

I know some folks on the forum that used their hybrid as a backup power source for the house so that they could slowly dilly dally around with the main breaker (including one or two multi day epic screwups on picking wrong hardware blocking the power restore) without affecting quality of life much. So that’s maybe a way to trade extra work and planning for cash otherwise paid to a contractor.

 

[prometheanfire]

The emergency shutdown of the solark will take care of shutdowns on the outside of the house.
You will still need disconnects that can locked open on all inputs and outputs, the transfer switch will most likely take care of the load output, the 200amp main and loadshed panel main breakers will need to be provided with a hasp for locking in the off position or other lockable disconnect. Many types of breakers have cheaply available hasps that can be added to meet this requirement. Ref NEC 2020 706.15(A)

The thing I'm wondering is if I will need a externally accessible disconnect switch for the smart load panel, the hasp requirement is good to note though.

No fuses are need on the solar input, in addition a separate PV disconnect switch is not required as this is built in to the sol-ark.
Since the PV panels will be installed on the house you will need rapid shutdown. Either an external transmitter or sol-ark's new built in one, and the appropriate modules at each solar panel. All PV wiring in the house must be in metal conduit and boxes, if you install a indoor PV disconnect it will need to be one in a metal enclosure. See NEC 2020 690.31(D) for more details. Also with each string on a separate run you most likely only need to use 12 AWG wire for each run. Don't forget to run a ground with your PV wires for bonding the panels and mounts. 6 awg is required where exposed on the roof, be sure to follow grounding requires of the mounting system you use.

I'm going to use 10AWG if I can, and will likely use sol-ark's new optimizers to stay in the family. That way I think the external rapid shutdown will also shut the panels down. I want a PV disconnect since from what I can tell the only way to disconnect the panels when connected directly is by software. It'd also allow me to turn off one of the parallel strings at a time if I desired, but that's just a bonus.

Batteries UL9540 on their own or UL1973 listed should be ok at the moment. The Pytes E-Box 48100R is fully UL9540 listed for up 12 batteries with the sol-ark15k and is comparable in price to eg4 batteries.

sol-ark does now offer their own optimizer and rsd modules. If you need them or their effect will depend on the layout of you panel strings.

DIY is possible for all this, including the main breaker. Having a professional do the main breaker and transfer switch wiring to your existing panel will help keep the time your house is without electricity to a minimum.

I'm going to go with eg4-LL partially for the cabinet, having a one year old...
Wife also veto'd a self install

Ok so that’s the smart panel upsell within their ecosystem. Makes sense.

You don't need to use their smart panel, you can run a normal panel to it as well.

 

[zanydroid]

I'm going to use 10AWG if I can, and will likely use sol-ark's new optimizers to stay in the family. That way I think the external rapid shutdown will also shut the panels down.

Maybe fly a drone up there to measure angle to sun and use an ephemeris calculator or shading simulator (perhaps done by engineering company) to estimate how much it’s needed. I did that manually (drone + climbing up to sight with my own eyes) instead of learning the proper solar design software.

I think there’s also shading design software from string only manufacturers that don’t believe in optimizers. Probably involves calculating number of shading hours and moving shaded strings to own MPPT or parallel to unshaded on shared MPPT.

I would strongly suspect that all panels on the same MPPT will need to be on optimizers. Or the optimizers would need to be configurable to achieve a total string voltage equal to the Vmpp of a parallel non optimized string. That seems highly unlikely to be exposed to the user.

On another thread it was suggested to consider a multi-port microinverter string to get a separate for shaded areas. That avoids needing to dedicate an MPPT.

I want a PV disconnect since from what I can tell the only way to disconnect the panels when connected directly is by software. It'd also allow me to turn off one of the parallel strings at a time if I desired, but that's just a bonus.

IMO brand disconnects are pretty cheap so you can spam on as many as you want as long as you keep them on the outside of the house (no metallic conduit requirement there).

I'm going to go with eg4-LL partially for the cabinet, having a one year old...

PowerPro is also sealed and should be cheaper by KWh

You don't need to use their smart panel, you can run a normal panel to it as well.

In that case at most it’s all or nothing load shed via a relay on the whole thing. Or a critical loads panel.

 

[pvgirl]

The thing I'm wondering is if I will need a externally accessible disconnect switch for the smart load panel, the hasp requirement is good to note though.

Shouldn't need one, as when RSD is initiated it will shutdown power. You will need lockable disconnect somewhere.

I want a PV disconnect since from what I can tell the only way to disconnect the panels when connected directly is by software. It'd also allow me to turn off one of the parallel strings at a time if I desired, but that's just a bonus.

There's a mechanical disconnect on the side of the sol ark

I'm going to go with eg4-LL partially for the cabinet, having a one year old...

One nice things about rack mounted batteries is they are a standard size, and there are plenty of racks for mounting them.

 

[chrisski]

May want to trust the contractor with designing this system rather than providing some specs.

An example is the 4/0 wire with a 200 amp class T fuse may not be ebough for a 48 volt 15 kW inverter. That may see 312 amps at 48 volts and 15KW, but if the voltage drops, amps will go up to pull the 15 kW and could approach 400 amps. The contractor could figure out the proper sized wire for fuses.

I'm going to be moving the dryer, oven and installing a car charger on that port.

That seems to be a lot to be putting on a single 15 kWh inverter. My Tesla Charger can charge up to 11 kW, so the any two could exceed 15 kW. My contractor did not want me putting the Tesla Charger on the 8 kW inverter unless I could limit it to 6 kW of charging. My only high wattage item I'm putting on my inverter will be an AC that pulls 4 or 5 kW.

 

[prometheanfire]

I need shutdowns so upgrading to optimizers isn't a huge jump. It also scratches my data acquisition itch. Also, I have photos in the top post (google photos link).

I might go the power pro route , not certain, I do like the rack form factor though.

All or nothing load shed is exactly what I'm looking for. May use their panel instead if the price is right but that just seems like added complication.

I actually have a rack for my servers already, could switch it to batteries, but I'd rather keep it as is

 

[prometheanfire]

May want to trust the contractor with designing this system rather than providing some specs.

An example is the 4/0 wire with a 200 amp class T fuse may not be ebough for a 48 volt 15 kW inverter. That may see 312 amps at 48 volts and 15KW, but if the voltage drops, amps will go up to pull the 15 kW and could approach 400 amps. The contractor could figure out the proper sized wire for fuses.

12kw is the max it can push or pull from battery, which is 250A, it can do 500A for ten seconds or 625 for 0.1 seconds. I've considered running parallel 0/4 cables as well and upsizing the fuse, not certain there (and a fuse isn't strictly necessary just advised IMO). I'm not decided on products, but something like https://www.wireandcableyourway.com/4-0-welding-cable-class-m-ul-csa could work as a single cable (two is better).

That seems to be a lot to be putting on a single 15 kWh inverter. My Tesla Charger can charge up to 11 kW, so the any two could exceed 15 kW. My contractor did not want me putting the Tesla Charger on the 8 kW inverter unless I could limit it to 6 kW of charging. My only high wattage item I'm putting on my inverter will be an AC that pulls 4 or 5 kW.

The 'smart panel' is a load-shedding panel, load on that panel goes away and is not provided by the inverter during an outage. My current usage reported every 30 seconds shows that I almost never go above the 12kW limit and have never breached the 7500W per leg limit. Just once or twice in the last year above 12kW.

 

[zanydroid]

One thing with the racks is that they stick out more, and that may make it more difficult to provide the code-required protection against them if you put them in the garage. Depends on how current your state is on physical protection code (in california they need to be either outside the driving path or protected by bollards, with a slim battery you can slip it out of the driving path more readily. tbh even if you are not yet code required to do physical protection / put batteries away from habitable spaces there are good reasons to follow the latest code).

All or nothing load shed is exactly what I'm looking for. May use their panel instead if the price is right but that just seems like added complication.

I'm pretty skeptical of smart panels. If you're able to DIY and swap it out if the company dies or the software sucks, sure. But some of these are $4000

Now the mechanical and electrical design of some of the panels is pretty cool. I just don't want to be an early adopter.

 

[prometheanfire]

It'll be installed in the basement, may have to add concrete board to the ceiling and enclose the area better, but it'll have enough space (also photographed in top post link).

Haven't seen pricing for the load shed panel from them anyway, so for now it's just a basic panel.

 

[pvgirl]

12kw is the max it can push or pull from battery, which is 250A, it can do 500A for ten seconds or 625 for 0.1 seconds. I've considered running parallel 0/4 cables as well and upsizing the fuse, not certain there (and a fuse isn't strictly necessary just advised IMO). I'm not decided on products, but something like https://www.wireandcableyourway.com/4-0-welding-cable-class-m-ul-csa could work as a single cable (two is better).

For the sol-ark15k you want two wires from your batteries/batteries bus bar to the inverter. The sol-ark 15k has 2 200 amp circuit breakers,for the batteries this combined with the breakers on many rack batteries provides protection and doesn't need a fuse.

For the battery wiring you will want to use a wire type that's allowed in NEC, welding wire isn't. MTW wire is highly stranded and very flexible like welding wire and is allowed for use by the NEC. 4/0 MTW wire: https://www.wireandcableyourway.com/4-0-type-mtw-ul1284-wire-2109-strand
With this wire if you crimp on lugs they need to be listed on class k stranded wire.

 

[pvgirl]

It'll be installed in the basement, may have to add concrete board to the ceiling and enclose the area better, but it'll have enough space (also photographed in top post link).

Newer building codes are requiring rooms with batteries and inverters to have walls and ceilings of unfinished wood-framed construction shall be provided with not less than 5/8-inch (15.9 mm) Type X gypsum wallboard, or other noncombustible construction.

 

[prometheanfire]

3/4 walls are already straight concrete, ceiling needs enclosed along with the last wall (with a metal door I imagine).

 

[prometheanfire]

No real changes, just clarifications I suppose, but here's the updated version.

 

[prometheanfire]

The emergency shutdown of the solark will take care of shutdowns on the outside of the house.
You will still need disconnects that can locked open on all inputs and outputs, the transfer switch will most likely take care of the load output, the 200amp main and loadshed panel main breakers will need to be provided with a hasp for locking in the off position or other lockable disconnect. Many types of breakers have cheaply available hasps that can be added to meet this requirement. Ref NEC 2020 706.15(I can't see whyA)

One thing of note is that the load-shed panel is located indoors, I'm not sure the hasp would be valid since it could theoretically be powered if the emergency shutdown switch does not work. If local code is happy with that emergency shutdown switch for the sub panel I can't see why they'd want the master transfer switch located outside as well.

 

[prometheanfire]

I moved the double throw transfer switch indoors, e-stop switch stops solar, inverter and sub-panel so that should be all that's needed for fire. (Main breaker still needed outside to protect the grid iirc). I can see an argument for not using a feed through lug and instead using a second 200A breaker for the transfer switch so that can be de-energized as well but am not hung up about it (MTS shouldn't need to be replaced as ofte as the sol-ark, hopefully...)

 

[pvgirl]

Design looks good, depending on what year NEC you are covered by you may have requirements for more disconnects.