Looking for assistance with Grid Support settings on Schneider XW6848+

DickyDck · June 2019

Hello everyone! I was referred here by someone over at solar panel talk for assistance with my semi new Solar setup. I have been trying to get support directly from Schneider, but they don't want to, and therefore will not help me with the various settings on my inverter. So sir Teknodave told me there was a Schneider expert roaming the forums over here I might be able to ask some questions about

For starters I should layout my system.
24 x Hanwha 320w panels, connected in 8 strings, 3 panels each (I could have the wording incorrect, forgive me)
2 Schnieder MPPT 60-150 Charge Controllers
1 XW6848 + Schneider inverter
Conext Combox, not like this is really part of the system but anyway I figured it is wired in
8 x 6v AGM batteries running series at 48v for battery backup and evening high amperage load shave
Standard 30amp NEMA generator plug, that hasn't been used or tested as I haven't gotten a generator yet.

So to my question, there are a bunch of various settings under the Grid Support section of the XW+ settings, that are all set to 0v or 0% or something defaulted to 0

Maximum Reactive Capacitive Power
Maximum Reactive Inductive Power
Maximum Reactive Power Grid Voltage
Minimum Reactive Power Grid Voltage
Inductive Voltage Set Point
Capacitive Voltage Set Point
Voltage Threshold To Start/Stop Excitation
Excitation Control Delay Time

When I tried to contact the people that installed my system, the generic answer of "your system is not large enough to worry about making adjustments" which means to me they are just either not interested in educating me, or they don't know themselves and the latter is more disturbing than the former.

Would anyone here be able to help me understand these options? I suspect they are not as simple as one would think, but a cliff notes explanation would at least get me started. The instruction manual doesn't mention them at all, and online searching hasn't been extremely fruitful. I thank you all in advance for any assistance you can provide!

Dave Angelini · June 2019

Hi, You really do not need to overthink this. These settings are for really large micro-grid applications and special power applications.
I think the installers told you the right thing. Schneider does not want you to, and frankly, I think they should say this in the manual.

Estragon · June 2019

I definitely defer to Dave on this. Although I think Schneider should (and probably does) make details of how these settings work available, I can understand why they wouldn't make it easy for non-installers to access.

The settings strike me as the sort of thing you might want to tweak if, for example, you ran a commercial or industrial operation and wanted to avoid or minimize kva charges. Most residential billing is done on plain kwh, so tweaking is likely to be moot at best. Making any sort of intelligent tweaks would likely involve pretty intensive engineering and analysis, well beyond anything a residential use can/should do.

mike95490 · June 2019

I don't sell to grid, but I would follow Dave's advice and leave them alone, they are not applicable in a solo application

Tecnodave · June 2019

DickyDck,

An engineering background is required to understand the in's and out's of those fine details. Those settings are there for multiple installation supervised by an engineer. Try to focus on your basic problems,

That said, I am not a grid tie expert, I'm off grid by choice, I don't got no stinking grid, I don't need no stinking grid! LOL

t00ls · June 2019

as others have said...they are for electrical engineers

your local utility might have certain setting they want you to have here.....but they should be there when they are set

the only setting you need to worry about is how much you put back vs. how much you use and what time....down to what voltage on the batteries...but that should be under sell

not sure of the menus on the new inverters....but thats where it is on the first gen inverters

Tecnodave · June 2019

DickyDoc,

reading through all all your threads one thing keeps coming up, your inverter drops out at 5kw, only at noon? Can you read your PoCo voltage when this happens. The issue just might be that the grid voltage goes over the maximum acceptable voltage that the inverter is programmed to accept. Here in PG&E land the grid voltage is often 245 volts AC so if you would try to push 5kw. into that the voltage might be pushed over the 250 volts maximum programmed into the inverter with the result that the inverter would shut down for at least 5 minutes for the inverters power up delay, then it would restart. So I suggest that you look at your voltage as delivered to the inverter. One possible fix is to make the feed wires to the inverter a larger guage to reduce the wiring voltage drop.

Thad said, I'm no Schnieder expert or grid tie expert, take what you will and throw out the rest.
david

DickyDck · June 2019

Hey guys, sorry for the late replies, I had a passing in the family and have been really busy, but I wanted to come back here now that things are settling down, and say thanks for the replies.

So let me elaborate on what my issue is, and I'll throw out for starters, the company that did my install under provisioned my batteries so I am only running 220ah worth of batts which might be the core issue.

Sometimes, I stress sometimes but it is relatively frequent, on sunny days I hit 4kw-6.2kw and if the brightness drops a bit, whether a little bit or a lot, the inverter stops, the display goes to "-.--" and stops producing power, but doesn't go into that limp-in mode for 5 minutes, it'll start climbing back up after about 10-15 seconds. It'll drop again later, no set timeline can be made with it. some days it is fine and doesn't do it at all, some days it is very consistent and frequent. I had a video of it doing it somewhere that I posted for people to look at that were trying to help me figure it out. I agree it likely has nothing to do with the advanced settings that go along with larger systems.

Dave Angelini · June 2019

400 Ah @ 20hr is minimum for an XW selling that much power. If it has as much solar as yours, it may need more. There is no capacity in your system to start with.

Tecnodave · June 2019

DickyDoc

The best course of action at this point is to get some readings from another source, not the inverter. The first thing I would do is measure the power input/output voltage right at the inverters input connector, using a good quality digital voltmeter such as a Fluke. If your local grid runs at a very high nominal voltage such as 245 volts AC and you push a lot of power into that, the inverter output voltage will go above shutdown voltage, which I beleive is 250 volts AC. This would be normal for the inverter to shut down when it sees voltage above the programmed acceptable voltage for that inverter. There is a grid qualification circuitry in every grid tie inverter that must "qualify" the grid as acceptable, this includes grid voltage, on some inverters looks at line 1 to line 2, others look at line 1 to neutral only, also is a frequency check to be sure that the grid is stable, so you cannot power up into a grid that is being repaired. The grid maintains a very stable frequency but voltage will sag and rise when power flow is at or near maximum capacity. The grid operator sometimes takes a few minutes to correct grid voltage when a huge load goes offline resulting in voltage far above normal. I've seen 512 volts on my local PG&E feed 480 volt lines, far above the norm but when that 100 h.p. water pump starts grid voltage drops down to more normal 485 volts. The highest I've seen PG&E service to a residence is 249 volts, guite enough that a grid tie inverter will have a problem sycronize with the grid

Maybe Dave Angelini will poke in and comment on the XW maximum grid voltage, that setting is best done by someone having expereince with that gear. Not by an end user.

DickyDck · June 2019

I do have a Fluke, and can run some measurements. I have a question since I know my incoming AC voltage is coming in at 240-ish, but in the Combox (and I could be reading this all kinds of wrong) I'm seeing it as 120 for AC1 which is the grid I think? Under AC Settings here below, am I just confused?

Image: https://us.v-cdn.net/6024911/uploads/editor/eu/xqiky4rin3c2.jpg

Tecnodave · June 2019

DickyDck,

Are these settings the factory default settings
Dave Angelini answer as to battery size is very correct, 200 a.h. battery on that large an inverter is way too small, like he suggests, 400 a.h. is way more like what is needed for an inverter that size, maybe even larger than that.

So several voltage checks to make, battery voltage when the inverter is putting a large amount of power, and line 1 to line 2 grid voltage when inverter is producing large amount of power, the inverter could well be shutting down due to lack of sufficent power.

What at does your system installer have to say about this issue? If he is truly qualified he should be there to support your system.

DickyDck · June 2019

these are defaults yes, and as for their qualification... well they had a a license and thew county accepted their paperwork so I can only assume they are "qualified".

Tecnodave · June 2019

DickyDck,

ok on re reading your post, you mention that when brightness drops at large power output the inverter shuts down, this is probably happening because your batteries and solar can support that output but batteries alone cannot, and the inverter drops out. If those batteries are golf cart types, then totally not appropriate for that large of inverter, my base batteries are 400 a.h. per bank and I have 2 banks for a 4000 watt inverter, but I'm totally off grid with no grid support or generator.

Tecnodave · June 2019

DickyDck,

I might add that using an inverter on too small of battery bank will cause way too much AC ripple on the DC cables to the battery due to the switching of the inverter, this in turn is very hard on the filter capacitors in the inverter, leading to early failure of the inverter.

Tecnodave · June 2019

DickyDck said:

these are defaults yes, and as for their qualification... well they had a a license and thew county accepted their paperwork so I can only assume they are "qualified".

Here in California,anyone can qualify for a contractor liscense, that certainly does not mean that person is qualified!
If he sold you on 200 a.h. of battery for a 6800 watt inverter, when the standard is 100 a.h. per 1000 watts of inverter, just where is his qualifications? Complex systems such as this really need an engineer to at least check plans for compliance with proven standards. Contractors are good at bolting things togather, they are not architects or engineers!

Find some suggestions as to appropriate batteries for this system as these AGM's will have a short life!

DickyDck · June 2019

Yeah, I should have gotten another 8 batteries to compliment these, but almost a year into them mixing up old and new batteries probably isn't the best plan of action. I'm thinking of going lithium for the next round, but damn if they aren't expensive as hell!

Tecnodave · June 2019

Lithium batteries are not only expensive but very unforgiving of errors, bang for the buck I'd still pick FLA. Big format ones such as 2 volt L-16's or Rolls-Surette 4KS25's, my Rolls-Surette S-530 L-16's are only 14 years old and still testing at full capacity, shipped out the door at Rolls June 26, 2005

BB. · June 2019

By the way, 100 ah @ 48 volts per 1,000 Watt inverter for lead acid deep cycle batteries is a suggested minimum.

200 ah @ 48 volts per 1,000 Watt of inverter can usually be justified pretty easily after a load analysis has been completed.

Bill

DickyDck · June 2019

Tecnodave said:

Lithium batteries are not only expensive but very unforgiving of errors, bang for the buck I'd still pick FLA. Big format ones such as 2 volt L-16's or Rolls-Surette 4KS25's, my Rolls-Surette S-530 L-16's are only 14 years old and still testing at full capacity, shipped out the door at Rolls June 26, 2005

I might consider those if I can create an outdoor holding area for them, but my AGMs are presently in my garage attached to my house which is under my master bedroom

DickyDck · June 2019

BB. said:

By the way, 100 ah @ 48 volts per 1,000 Watt inverter for lead acid deep cycle batteries is a suggested minimum.

200 ah @ 48 volts per 1,000 Watt of inverter can usually be justified pretty easily after a load analysis has been completed.

Bill

Load analysis, being total max load or average use load? Going through my crit loads panel on average is maybe 1.5kw when I'm working from home. max can reach up to 3-5kw for water pump and heater.

Tecnodave · June 2019

As per BB recommendations 680-1360 a.h. Battery, a 200 a.h. battery does not have the capacity to damp the pulsating current that the inverter will produce operating at that power level, it does not draw a steady DC current from the battery, it pulses with the AC waveform, this undampened pulsing will overwork the capacitors in the inverter and cause early failure.

BB. · June 2019

DD,

The short answer is know everything about your loads.

Peak Watts (surge) (size of inverter)

Average Watts for hours at a time (how fast do you discharge--2,000 Watts for 6 minutes water pumping is 200 WH... a refrigerator averaging 60 Watts x 24 hours per day is 1,440 WH per day)

Total Watt*Hours per day (size of fuel tank)

All the above affects the system design.

And you have choices when you pick loads... Inverter based well pump may have almost zero surge.

Running heating devices can be a big burden for of grid solar. You can see above running a 60 Watt fridge and a 60 Watt heater (or 60 Watt light) 24 hours per day may be something like $0.30 per day for 1.44 kwh per day for utility power... For solar, that could start with a few thousands of dollars worth of hardware just to get going...

Bill

DickyDck · June 2019

ok, so it seems the quick thing to do is to get a large @$$ battery bank, and FLA batts seem to be the way to go. I think I'll have to create some sort of encasement with ventilation since I don't have a place to put the batteries outside of my main living domicile just yet. The thought of off-gassing into my home is just a really unsettling thought.

Dave Angelini · June 2019

It is against the building code to have almost any battery in living space, your insurance would be useless if there were a fire.

Tecnodave · June 2019

Yes , absolutely build a sealed box for the batteries if you need them inside. Completely sealed with a 4" in vent from outside air down low into the box and a 4" vent stack from the highest point in the box going out and up. There are vent stack fans at solar-electric but I just use common cheap computer cooling fans for this use. Do not use a brush type motor fan.....computer fans are permanent magnet and do not create sparking....this fan can be controlled by the charge controller auxiliary output to energise when charging.....Im going to suggest ABS vent pipe as used in the west coast, if ABS pipe is not available in your neck of the woods, then PVC schedule 40 for the vent. I have noticed that ABS pipe is not available on the east coast as PVC is used for drain,waste,vent there, here in the west we use ABS pipe for drain,waste,vent pipe, in any case totally glued connections......

OK THE RIOT ACT.....Hydroden gas mixed with Oxygen gas as caused but charging FLA batteries is very flammable and burns at 6250 feet per second! That's 1.25 miles per second! Do not cut any corners on positive ventilation of the battery box.....don't even think about it. And if the gas water heater is nearby it needs to be boxed in and vented to outside air, the combustion air as well!

At at the three mile island nuclear power plant meltdown they said "We had a rapid hydrogen burn" At Fukishima Nuclear power plant they admitted a hydrogen explosion! Zirconium fuel rod cladding flashes into hydrogen gas at meltdown, that is what caused the horrendous explosions at Three. mile Island and Fukushima totally destroying all the safety controls at Fukishima leading to a much more massive loss of nuclear materials into the environment.
hydrogen gas is no toy to fool around with, it's used in welding, much hotter than Aceteyne! Oxy hydrogen burns at 5900 degrees Fahrenheit!

BE SAFE!

DickyDck · June 2019

Dave Angelini said:

It is against the building code to have almost any battery in living space, your insurance would be useless if there were a fire.

So it technically isn't living space since it is the garage, BUT there is living space right above it. The county came out and signed off on everything after installation so it must have met county/state code regulations. I do agree though, since if things went boom I would be the first to know as the master bedroom is right above it

DickyDck · June 2019

Tecnodave said:

Yes , absolutely build a sealed box for the batteries if you need them inside. Completely sealed with a 4" in vent from outside air down low into the box and a 4" vent stack from the highest point in the box going out and up. There are vent stack fans at solar-electric but I just use common cheap computer cooling fans for this use. Do not use a brush type motor fan.....computer fans are permanent magnet and do not create sparking....this fan can be controlled by the charge controller auxiliary output to energise when charging.....Im going to suggest ABS vent pipe as used in the west coast, if ABS pipe is not available in your neck of the woods, then PVC schedule 40 for the vent. I have noticed that ABS pipe is not available on the east coast as PVC is used for drain,waste,vent there, here in the west we use ABS pipe for drain,waste,vent pipe, in any case totally glued connections......

OK THE RIOT ACT.....Hydroden gas mixed with Oxygen gas as caused but charging FLA batteries is very flammable and burns at 6250 feet per second! That's 1.25 miles per second! Do not cut any corners on positive ventilation of the battery box.....don't even think about it. And if the gas water heater is nearby it needs to be boxed in and vented to outside air, the combustion air as well!

At at the three mile island nuclear power plant meltdown they said "We had a rapid hydrogen burn" At Fukishima Nuclear power plant they admitted a hydrogen explosion! Zirconium fuel rod cladding flashes into hydrogen gas at meltdown, that is what caused the horrendous explosions at Three. mile Island and Fukushima totally destroying all the safety controls at Fukishima leading to a much more massive loss of nuclear materials into the environment.
hydrogen gas is no toy to fool around with, it's used in welding, much hotter than Aceteyne! Oxy hydrogen burns at 5900 degrees Fahrenheit!

BE SAFE!

I'm going with an outside enclosure if I go that route, or just getting AGMs again. It actually looks like some off brand AGMs are on par with the price of FLA, but I am researching reviews and reliability.

Tecnodave · June 2019

My FLA batteries are outside of my living space in a repurposed commercial fiberglass laundry tub, well ventilated. With outside venting and stack. Sometimes when equalizing I still get that rotten egg smell of sulphuric acid, very unpleasant.

Dave Angelini · June 2019

An AGM battery in a failure mode is just as dangerous as a flooded battery. A garage is not living space so you are fine there with a proper safe installation.

mike95490 · June 2019

DickyDck said:

I'm going with an outside enclosure if I go that route, or just getting AGMs again. It actually looks like some off brand AGMs are on par with the price of FLA, but I am researching reviews and reliability.

AGM requires the same venting as FLA. You just don't need it till the cells start to fail. Surprise !!

If your garage was built like mine was, it is all a 1 hour firewall, fire rated interior door and thick sheetrock. The Kaboom would still tear it apart, but it meets code.

Looking for assistance with Grid Support settings on Schneider XW6848+

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