Schneider XW8548 configuration question

Scooterbike

Can someone maybe help.
Just installed the XW+ 8548 with 60/150mppt, only 200Ah @48v (lead crystal) for now, and on Grid Support. All seems to be working well, apart from 1 issue:
inverter runs/ramps up and +-5s later it switches to AC passthrough for a few seconds, then back to Grid Support for a few seconds, continuously. However, when the sun is out and the DC input exceeds the load, then this constant switching stops and inverter stays on Grid Support, as it is intended to do. Note the load varies (500w-2500w) but the switching issue remains regardless of the load.
Is the battery bank to small? BUT, when I switch off the AC1 grid supply, the inverter happily runs on the batteries for many hours....

current settings:
Load Shave enabled @0amps;
Sell disabled;
LBCO @44v;
Recharge @50v;
Grid Support @ 47v, also tried 60v, cannot see a difference in performance;

BB.

Welcome to the forum Scooterbike!

I probably cannot help you with the programming... But a few questions.

First, do you have a link to your Lead Crystal batteries? I have heard of the term before, but was not really sure what type of batteries those are... Other than just a GEL or possibly AGM type battery.

Next, what size of solar array do you have?

And a 200 AH @ 48 volt battery bank is (usually) terribly small for a 8.5 kWatt AC inverter system... Typically, I would be suggesting a ~850 AH @ 48 volts minimum battery bank for a 8.5 kWatt AC inverter if you are planning on using anywhere near its rated power.

Which leads to the next question, what are your planned loads (Watts, peak Watts, kWatt*Hours per day).

-Bill

mike95490

Sadly, while I have the smaller cousin to your inverter, I've not used grid support/load shave since I have no grid. But I can help with gen support or battery charging via AC2

sub3marathonman

Scooterbike wrote: »

Can someone maybe help.
Just installed the XW+ 8548 with 60/150mppt, only 200Ah @48v (lead crystal) for now

Is the battery bank to small? BUT, when I switch off the AC1 grid supply, the inverter happily runs on the batteries for many hours....

current settings:
Load Shave enabled @0amps;
Sell disabled;
LBCO @44v;
Recharge @50v;
Grid Support @ 47v, also tried 60v, cannot see a difference in performance;

I too have the smaller version XW6048, and I'm definitely no expert even for that, but you can try without worrying about doing any damage to disable Load Shaving. I think it does some strange things, and with it being set a 0 amp might act even stranger, at least if you don't disable it change it to 1 amp.

Also, it seems that nobody will ever update the erroneous information about battery sizing. While it says "100 amp hour minimum" what it means is that 100 amp hour is the minimum with an extremely small PV system. Solar Guppy, an expert on these, always recommended 100 ah / kw of PV. The "ripple current" from the inverter will be brutal on this battery bank. For the current situation, I would also research throttling back the PV array by setting the maximum charge rate from the 60/150mppt to about the amperage you could expect from a 3kw or 4kw at the most PV array. For my system, I had set it back lower because my batteries were 357ah with a 4.7kw PV system, and really never used the inverter over about half the 6kw rating, usually closer to a quarter or 1.5kw output.

I think the Grid Support voltage should be set to about 53 or 54 volts, somewhere there was a discussion with Solar Guppy involved, it may have been the big F49 fault thread, but I'm not sure.

I think I'd also increase the LBCO higher, just to make sure the small undersized battery bank currently in use isn't damaged.

As I said, I'm no expert, but any or all of these suggestions should be OK to try without possibly doing any damage to anything.

Vic

Searched for the Lead Crystal battery site, found it, but they want an e-mail address just to see the pdfs, so did not see them.
It DOES appear that this company does make Sealed batteries, so, it is possible that the very small battery bank is AGM, which can supply significantly more peak currents and will tolerate much larger charge currents ...

sub3marathonman wrote: »

Also, it seems that nobody will ever update the erroneous information about battery sizing. While it says "100 amp hour minimum" what it means is that 100 amp hour is the minimum with an extremely small PV system. Solar Guppy, an expert on these, always recommended 100 ah / kw of PV. The "ripple current" from the inverter will be brutal on this battery bank. For the current situation, I would also research throttling back the PV array by setting the maximum charge rate from the 60/150mppt to about the amperage you could expect from a 3kw or 4kw at the most PV array. For my system, I had set it back lower because my batteries were 357ah with a 4.7kw PV system, and really never used the inverter over about half the 6kw rating, usually closer to a quarter or 1.5kw output.

I think the Grid Support voltage should be set to about 53 or 54 volts, somewhere there was a discussion with Solar Guppy involved, it may have been the big F49 fault thread, but I'm not sure.

I think I'd also increase the LBCO higher, just to make sure the small undersized battery bank currently in use isn't damaged.

As I said, I'm no expert, but any or all of these suggestions should be OK to try without possibly doing any damage to anything.

I, too, am no expert on the Schneider inverters, or GT systems.

BUT, my recollection that Solar Guppy recommended 100 AH of battery C, "per KW of power to be SOLD TO THE GRID".
It does seem to me that it is more difficult to sell to the grid, than to supply local loads from an inverter. If the voltage output of the inverter is even slightly less than that of the grid, believe that the power sold is reduced to a point that allows the inverter's output voltage to rise to a value just above the grid's voltage (as seen by the inverter).

Since Scooter.. is not selling power to the grid, the absolute requirements for battery C may be reduced, at least a bit. Perhaps this is a bit of a moot point ...

Also, reducing the output current limit on the SCC to try to save the battery from (the yet, unknown) max current acceptance, kind of compounds the undulation issue, IMO.

This system does seem poorly balanced. I know absolutely nothing of Grid-interactive systems, but, historically, Schneider seems to have had some significant bugs in their inverters, when dealing with all of the fine detail of the Grid (from reading of those issues on this Forum).

And, YES, specs on the type and acceptable charge and discharge/peak current specs would be helpful, as would the amount of PV available.

Opinions, FWIW, Vic

Blackcherry04

If you are not selling to the grid, I'd switch the AC input over to ac2 and use Generator Support. It's much easier to use and the support is based on the support setting and not battery voltage. Generally you set the ACin amps and then set the support at least 2 amps below it so it has time to react to loads. You have plenty of range with 4 - 48 amps of AC support.You can play with the settings and then use as much battery power as you want for load support. This is how it works on all the other inverters that do not have 2 inputs.

Page 3-21

pvpower.com/uploads/products/xwoperation.pdf

Dave Angelini

The installation guide for XW inverter chargers (all models) has said "minimum required battery size is 400AH" since 2007.

SkiDoo55

Sure your inverter isn't a XW 6848. Do you have an SCP or ComBox on the system. Is the MPPT Networked to the inverter. If you do you can set grid support enhanced and the batteries will get a full charge cycle and excess will be passed to load. Have to look at some settings for grid support and no sell with load shaving. Grid support voltage needs to be set 4 vdc above your Bulk/absorb setting. When you get the recommended charging parameters from battery mfg will probably need to set custom settings. 200 ah of batteries for a 6+KW inverter is too small. Should be over 600 ah to effectively filter the AC ripple out.
For load shave and grid support the connection needs to be on AC1. Current needs to exceed the Shave amps setting. Load shave start stop times need to be valid. Grid suport enabled, sell off. Battery voltage +2 vdc of grid support setting.
Might also try just grid support on no sell and load shave off. Should deliver all excess from panels to loads before pulling from grid.
I have mine set grid support enhanced but I am selling excess back.

Dave Angelini

He probably has the 230VAC European/Aussie model. My Aussie friend just put one in and with 5 Blow dryers running (5 girls) he saw 7,500 watts going into the air.

BB.

I guess that Scooterbike is from South Africa or there abouts.

-Bill

SkiDoo55

Dave Angelini wrote: »

He probably has the 230VAC European/Aussie model. My Aussie friend just put one in and with 5 Blow dryers running (5 girls) he saw 7,500 watts going into the air.

You are correct XW 8548+ E still the setting I think still need to be adjusted for it to behave correctly.. With just grid support and sell off mine will use all of the available surplus energy form the panels to support the load and cut demand from the grid. In GS enhanced it will charge batteries as priority and not deplete the bank ot low voltage cutout. Still will need an SCP or ComBox to set some of the advanced settings.

Juan_pinoy1

Ive been running my Schneider xw 5548+ for almost a year now. Combined with an Outback fm80.

Here from my experience you may try to adjustyou recharge voltage to a lower one maybe 48 so that the inverter wont ramp up. I believe it ramps up everytime your batteries are able to rest and go back above 50 vdc.

I noticed this at beginning of using the xw 5548, my settings are as follows:

Recharge voltage 46vdc
Grid support 48vdc
Lbco 44

Charger off
Grid support on
Sell off

with those settings as long as my batteries are above 48vdc and loads are not too high, inverter will power most of my loads, xw seems to have an overhead of around 50-80 watts meaning the inverter still draws power from the grid, even during solar noon and a fully charged battery.

Hope this helps, hopefully more xw + users join the forum so we can exchange views/experiences with the xw+.

BB.

Juan,

Welcome to the forum.

Regarding your programmed voltages--Those are very low and if you have a standard Lead Acid battery bank, your batteries are not getting properly charged. Have you measured the voltage directly at the battery bank with a DMM?

For example, your Grid Support voltage (float charging) should be around 54.4 volts, and the Low Battery Cut Off, I would suggest ~46.0 volts minimum. 44 volts (11 volts on a 12 volt battery bank) is pretty low--Unless you have some pretty large surge loads/smaller battery bank. Deeply cycling a lead acid battery bank (below ~50% state of charge) often will give you a shorter battery life.

-Bill

BB.

Also, I should add, the Schneider XW units are known to draw a minimum load on the AC mains. So far, nobody has been able to reduce that to zero Watt draw when running Grid Tied.

-Bill

Dave Angelini

Bill, the reason the XW default low battery cut-out  over the years has changed between 46vdc and 44vdc is there almost always is a load going and so the inverter input voltage is not really that low.  They recently added a hysteresis setting to really nail it down.

Snowing here all night and now, it may be a no school day for the kids tomorrow. Not a good day to drive up.....

Juan_pinoy1

Thanks for the warm welcome Bill.

I just wanted to help @ScooterBike with his problem of his xw ramping up and down, as these settings worked for me, as for the voltages i know they're on the low side, but like @Dave Angelini said since theres always some form of load drawn from the xw+ the battery voltage will be lower than their actual resting voltage.

YehoshuaAgapao

Trojan and Crown don't like going below 50%. Rolls/Surrete 4000 series can go to 30%.  5000 series do fine to 20%. Surrettes have thicker plates but also higher internal resistance.  Never below 20%.

Vic

YehoshuaAgapao said:

Trojan and Crown don't like going below 50%. Rolls/Surrete 4000 series can go to 30%.  5000 series do fine to 20%. Surrettes have thicker plates but also higher internal resistance.  Never below 20%.

Hello Yehosua..,

Am still trying to understand what the above is trying to say,  especially In the context of the OP referencing  Grid Support voltage ...

Most of the battery manufacturers referenced in your above Quote make several different styles/types of batteries,  for different applications ..

Yes,  usually batteries with thicker plates,  compared to others,  will have higher impedance when compared to batteries with more,  but thinner plates.

Each of those manufacturers do make a number of battery styles.

What are the percentages that you have referred to?   Are those DOD?  SOC ??  ...   OR,  ??

Thanks,   Vic

YehoshuaAgapao

Perentages are State of charge.