Schneider Electric Conext SW 4048 Hybrid Inverter with AC Support multiple problems

AdrianB · April 2017

My solar system configuration is:

1.Conext SW 4048 220V inverter.
2. Conext MPPT 60 PV charger
3. 200Ah 48V battery bank.
4. 1.5kW solar panels.
5. Conext ComBox for monitoring.

All devices have the firmware upgraded to the latest version.

I. First problem, and the biggest one is this:
"NOTE: To prevent injecting current into the grid from the inverter, there is less than 2 amps of offset allowed from the grid to flow into AC IN even when Load Shave Amps is set to 0" Documentation update on Schneider Electric website.

and this NOTE is translated to the following picture:

Image: https://us.v-cdn.net/6024911/uploads/editor/q7/cp97hy66euz3.jpg

With full sun outside and for a 234W output load on AC i have a 255W input from the grid and ZERO input from the solar panels.

I hope there is a way to disable this 2 Amps offset, because this it's making the solar system useless, maybe a hidden service menu or a custom firmware update..? At this point i had to manually disconnect the grid from the inverter, in order to use the solar energy .

And with the latest firmware update you cannot set the load shave to 0, it is minimum 1 Amp, so a minimum of 3 Amps (660W ) must be drawn from the grid in order use solar energy.

II. The second problem:

Battery voltage readings and charging values are totally off by 1.5V !.
As you can see in the picture, the battery is in float charging with a set point of 53.8V. The MPPT it's reading 55.3V and the CSW 56.2V.

Also i measured the voltage with a calibrated multi-meter and i have 54.8V.

And some other issues with wrong power reporting...

Image: https://us.v-cdn.net/6024911/uploads/editor/hl/m3wt9de6m1fm.jpg

And, not to forgot that the first ComBox failed after 6 hours! And they eventually replaced the unit under RMA, after 2 weeks...

mike95490 · April 2017

wow. Have you shown this set of pics to Schneider ? I don't have grid, and never investigated the gridtie setups.

Dave Angelini · April 2017

Who installed the system? As Mike said, if this is new equipment you should check with Schneider.

AdrianB · April 2017

Hi,

I didn't show this to Schneider yet, the equipment it's new and was installed by me as the Install-Owners-Guide specifies.

Dave Angelini · April 2017

I always suggest to people with the grid who probably have (guessing) little experience to first get the system working as if it were Offgrid.
It is helpful to post a picture of the electronics and battery. The more information you post the more helpful this can be.
Your location can help along with what you intend to do. Good Luck!

AdrianB · April 2017

Hi,

At this time, between me and the solar system is a 100 mile distance, i can only do remote access to the ComBox, i'll add some pictures in the weekend.

And some detalils:

AWG 3 wires were used to connect the inverter to batteries, with maximum length of ~1m in order to reduce power loss.

AWG 5 wires used to connect the charger to batteries.

Newmax battery

Image: https://us.v-cdn.net/6024911/uploads/editor/d5/2jzl9j9lo2fy.jpg

The above picture it's with grid disconnected.
And current reporting from inverter it's oscillating from -3.5A and +3.5A.

Estragon · April 2017

Those wire sizes seem light to me to me.

Dave Angelini · April 2017

I see quite a few problems. Start with the obvious. Clean tight/torqued connections?
The 200ah is the 20 hour rate correct?

AdrianB · April 2017

All connectors and cables are brand new and high quality. Connectors tight and shiny.

I just measured the voltages again at battery terminal, inverter (no load) screw and MPPT connector, i have the same voltage with my multimeter in all 3 points, in this case is 50.9. Combox is saying 52V for inverter and 51.5 for MPPT.
Seems a calibration problem for me. Is there any way to calibrate these units ?

gbaig · April 2017

AdrianB said:

Hi,

At this time, between me and the solar system is a 100 mile distance, i can only do remote access to the ComBox, i'll add some pictures in the weekend.

And some detalils:
AWG 3 wires were used to connect the inverter to batteries, with maximum length of ~1m in order to reduce power loss.
AWG 5 wires used to connect the charger to batteries.
Newmax battery

The above picture it's with grid disconnected.
And current reporting from inverter it's oscillating from -3.5A and +3.5A.

How you are able to monitor through combox? I have been trying to remotely access but no luck. I will appreciate if you could give me step to configure it to access remotely.

AdrianB · May 2017

You have to do a port forwarding on your router, and use a free DDNS if you have dynamic ip. And most probably you will have to change the communication port from combox config.

b. ecologìcAll · September 2018

I. First problem, and the biggest one is this:
"NOTE: To prevent injecting current into the grid from the inverter, there is less than 2 amps of offset allowed from the grid to flow into AC IN even when Load Shave Amps is set to 0" Documentation update on Schneider Electric website.

and this NOTE is translated to the following picture:
With full sun outside and for a 234W output load on AC i have a 255W input from the grid and ZERO input from the solar panels.

I hope there is a way to disable this 2 Amps offset, because this it's making the solar system useless, maybe a hidden service menu or a custom firmware update..? At this point i had to manually disconnect the grid from the inverter, in order to use the solar energy .

And with the latest firmware update you cannot set the load shave to 0, it is minimum 1 Amp, so a minimum of 3 Amps (660W ) must be drawn from the grid in order use solar energy.

Has anyone found a solution to this problem?? anything else than to manually turn on and off the AC input? feels like a punch un the face to invert money in an inverter that was advised to use the sun power every time and only the grid when there is no sun, but if loads are about 300w, the inverter will always have input from the grid and zero input from solar panels
some people are using an ac 240 timer, in order to disconnect during sun hours and reconnect back to the grid at nigh time. but feels like money in the trash to buy an expensive inverter because all the features but can not do the one thing it was buy for.. to use sun energy every time its available

t00ls · September 2018

what was the reason you chose an SW over the XW

the old trace/xantrex SW was barely grid tie and mostly used for marine and rv applications

the XW series was specifically made for offgrid and gridtie or just plain backup power if you didnt have solar

BB. · September 2018

I am not sure--But I think that the 'old' SW from Trace/Xantrex (long out of production) is not the same unit as the current Conext SW unit from Xantrex/Schneider...

-Bill

mike95490 · September 2018

Can you look at the imbalance between L1 & L2 loads (in a text listing in the Combox readout) Somewhere, I heard a load imbalance screws things up.

MrM1 · September 2018

b. ecologìcAll said:
Has anyone found a solution to this problem?? anything else than to manually turn on and off the AC input? feels like a punch un the face to invert money in an inverter that was advised to use the sun power every time and only the grid when there is no sun, but if loads are about 300w, the inverter will always have input from the grid and zero input from solar panels some people are using an ac 240 timer, in order to disconnect during sun hours and reconnect back to the grid at nigh time. but feels like money in the trash to buy an expensive inverter because all the features but can not do the one thing it was buy for.. to use sun energy every time its available

At loads of around 300 Watts, that is the behavior of the SW. It will not (hardly at all) pull from the battery/solar, but instead will inject power from the grid, even in a perfectly balanced system load between the L1 and L2 BECAUSE of the 2 amp limitation. There is no way to disable this. It is what it is. Load Shaving, which basically does the same thing as AC Support mode but with a start/stop block has a setting for amps, and it will let you set it to 1 amp, but it still has the 2 amp limit and in my testing actually does not do as good as AC Support mode. That is, in Load Shaving, the load has to be higher (more watts used) than in AC Support mode to lower grid support.

You are never going to get away from some power being injected from the grid. And you will have a really hard time balancing the loads between L1 and L2 ALL THE TIME.

I realize the Manual Says differently, but my theory is that the SW was originally designed for 240/230v grid locations. It only gives problems in Split Phase locations like N. America where you are using an L1 and L2. It requires the load to be balanced.

Here is Schneider's Official response to the sections in the manual about AC Support mode and the issue in NA. It appear to have been posted by Schneider sometime early 2018. (I never found it until then and it seemed to start circulating around the forums about then)

https://www.schneider-electric.us/en/faqs/FA332947/

What can you do?

Use more battery at night, and you will use more solar in the day for charging. Your Charge controller will charge regardless of your daytime loads.
Realize that under about 300 Watts (give or take), the SW in ACS mode will pull very little from the battery/solar day or night, even in a "perfectly balanced world" in NA. It is going to get that first 250-350 watts from the grid at all times. (2 amps). The only way to change this is the turn off AC in from Grid/Genny. Your timer idea might work here.
Set up a diversion load from your Charge Controller like a 240v lower water heater element (say 1000 watts), connect the lower part of your Water heater to the inverter, and you will cut your power bill significantly. If you can set up a relay that works with your Charge controller, it will only heat water during the day. Long read, but here are the details of what I did
I found installing an Auto Transformer, like the one from Outback Power - the PSX-240. made AC Support mode work almost as advertised. You say "wow that is expensive" but look at it this way, If you got a good deal on the SW and add the PSX-240 and the SW SCP, you are still probably less money than any other major brand of 120v inverter in the same class. Look for deals on the PSX-240 on ebay (used or closeouts)
Further, I have found, once the AT is installed, it is better to have your higher loads on L1 (so long as you do not over load the L1 side). Example, Fridge on L1 at 15-300 Watts and 200 Watts of LED on L2 works better than the other way around

For me the Auto Transformer was a game changer for the SW-NA. I asked this question all over the internet back 7 months ago about AC Support mode and why it did not seem to be working, I think it was @ButchDeal that said deep in one of those discussions one day, "you need an autotransformer". That is when I started this thread about Using an AutoTransformer with the SW. On page 2 at post #37 is where I started the install. I post user data of before and after (with/without) the AT and you can see the results are significant.

Sorry for the long post. Hope this helps. Good luck.

b. ecologìcAll · September 2018

since the solution almost everybody do is to manually turn off ac in in the morning and turn it back on in the afternoon. i think that process can be automated with a timer. Im looking at this one at amazon. it can be mounted in the din rail inside de ac panel. in PR at about 9am the batteries are completely charged, and we have sun light at about 6pm. so my plan is to set the timer to cut ac input at 9am, and put the grid back on at about 3pm, so we have from 3pm to 6 pm to recharge the batteries in case there is a power outage during night.
it will be nice to instead of a timer, automated the process using battery voltage, so the user/installer can set a desire battery voltage to cut the grid, and desire voltage to turn the grid back on.
for example, turn off the grid at 25Vdc, turn grid on at 24.5Vdc

Image: https://us.v-cdn.net/6024911/uploads/editor/ne/k4vf0w3zi5h5.png

Dave Angelini · September 2018

"almost everybody" ? Most people use this inverter/charger "CSW" for offgrid and they work fine for small systems. The same problem for grid-tie happens with the small Outback Radian and probably will happen with their new Skybox. Just a ridiculous use for a grid application for a small inverter and small arrays, but....

b. ecologìcAll · September 2018

, but....

but... when it was advertised to work well, with a lot of features, bells and whistles...

why a client may choose an SW over the XW?
1. it was advertises to be the same, only smaller and without netmeterin
2. in PR its hard to get the netmeterin approved, the permit may be rejected by a lot of excuses from the utility without any logic reason.
3. there are sectors where the feeder is full so utility will not receive the interconnection application
4. there are clientes with small homes that their peak is just 1,500 w, and only consume 10 to 12kwh/day
5. last but not least.... it was advertises to work as good as the XW, only smaller, without netmetering and cheaper!!!
So, by the client side, it was a no brainer to choose an SW over an XW.
But... with all the experience and troubles the SW are giving... I am not recommending the SW no more... just for off grid applications or people that realy dont have the money for an XW installation, i first offer the XW if the client dont have the budget, then I offer the SW but listing all the limitations it have

MrM1 · September 2018

since the solution almost everybody do is to manually turn off ac in in the morning and turn it back on in the afternoon.

Oddly this the first I have ever heard a timer. I thought about using a networkable on/off timer, but I do like the idea of a timer an may add a simple hi current timer to control it even better. But you specifically asked, "Has anyone found a solution to this problem??" I offered you several, including the limits of the inverter, but then you go back to the timer idea you had already mentioned.

So do you have a link for the pic of the timer you posted above?

littleharbor2 · September 2018

MrM1 said:

since the solution almost everybody do is to manually turn off ac in in the morning and turn it back on in the afternoon.
.
So do you have a link for the pic of the timer you posted above?

Easy enough to find online. The model the OP has shown is half the list price ($39.95) on eBay.

http://www.electrodepot.com/contactor.htm

b. ecologìcAll · September 2018

60 amp contactor with timer, din rail mount
https://www.amazon.com/Pole-Programmable-Timer-Control-9344204/dp/B01GXYNMO2/ref=sr_1_4?s=hi&ie=UTF8&qid=1537460306&sr=1-4&keywords=timer+60+amp&dpID=41gljfaVgoL&preST=_SX300_QL70_&dpSrc=srch

if instead of a timer, some device that can be set to program it to open the contactor when the battery is at 90% DOC and close it when the battery is at 60% DOC, it will be even better! so user dont run out of batteries during rainy days

MrM1 · September 2018

b. ecologìcAll said:

60 amp contactor with timer, din rail mount
https://www.amazon.com/Pole-Programmable-Timer-Control-9344204/dp/B01GXYNMO2/ref=sr_1_4?s=hi&ie=UTF8&qid=1537460306&sr=1-4&keywords=timer+60+amp&dpID=41gljfaVgoL&preST=_SX300_QL70_&dpSrc=srch

if instead of a timer, some device that can be set to program it to open the contactor when the battery is at 90% DOC and close it when the battery is at 60% DOC, it will be even better! so user dont run out of batteries during rainy days

What is causing the trigger? What are you connected it to that is detecting DOD?

enginerd · May 2022

I know this is an old post, but I am in the same situation here. I am very unhappy with SW4048 self consumption for my residential hybrid system in North America - I have 240V split phase inverter running a 240V sub panel, and i use ~600 - 1200KWH per month depending on season. I have moved almost everything to the sub panel except for the large loads from the clothes dryer and the electric range, as well as circuits that are almost never used. SW4048 - SCP, MPPT60, 3400W Array@100V, 2XBank of 4 Eaton 75AH AGM batteries = 300AH@48V.

The 2 amp ~480W requirement is an issue, but the bigger issue I see is actually the balancing requirement. I can have a load of 1500W and I get 100W from the grid if 1 leg is only 500W. Even by rearranging my circuits trying to balance the load L1 and L2 Its nearly impossible to get decent self consumption on this inverter. I can have a bright sunny day and used 20KWH at home and i get 3 kwh from my 3500W solar array. I leave and my battery is 100% I come home and the battery is 100% and it used 3kwh

The only time I see a reasonable self consumption is when the well pump comes on and i have 240V and even load on both legs. Overall pretty unimpressed with this product and its marketing as a self consumption system. I often see 1500W load and only 200W coming from the solar. I switch the breaker off and my array output jumps 1500W. I turn on some more loads and the array has peaked at 3500W when the battery got low.

This unit, and solar system ~(9K$ self install) will NEVER pay for itself in self consumption. I get that grid tied would be best for payback, but the "hybrid" is really a lie - this system is terrible at self consumption. I wanted a hybrid that would provide battery backup needs here for potential weeks without power, but I wanted to actually get the system to pay for itself in 7 years.

The only way to get full usage from my array is to leave this system off and run off grid, but I find my night loads are too high, or cloudy days are potentially deep cycling so I either have to double or triple my battery bank, or cycle it really deep. By the time I get payback I will need a new battery bank from the deep cycling, and then reset the payback counter.

At the moment I am left turning the breaker on and off at 7 am and watching the weather to make sure my wife doesn't kill the battery with laundry/dishwasher/toaster oven/etc during the day while the breaker is off. I mostly err on the side of protecting the battery and miss out on solar. I can get 8-15 kwh generation from the array and the battery is full when I get home from work at 6:30 on a partly sunny day. on a cloudy day I have come home to low voltage warning.

I have been considering using the MPPT60 charge controllers analog output to drive a contactor on the AC input to the SW4048.
I was wondering if anyone has done this, and what the settings are that they used for the thresholds with AGM batteries?

If i use a normally closed contactor, and setup the analog output to turn on at say 53V, and power a 12V relay to drive the AC contactor I can make the unit go off grid when the solar output is good. If I set the threshold for turn off at 51V (with a 15 minute delay) I can have the unit automatically turn the AC back on when array drops out and the battery is loaded without solar input. The delay can prevent trips from high loads for short periods (well pump + etc) This is essentially what I do when I am home - I monitor the voltage and turn the breaker back on when the array output is low, but I am "working" for 1-2$ here a day and want to automate this to get a payback without having to work for it or think about it every day.

Anyone have a setup like this? is there a problem with the AC input turning on and off a few times a day for years? I think the debounce timer will help prevent it toggling too much if I set the thresholds right for the charge controller output.

Why can't schneider do this? I know there is a contactor inside the unit that does this very function ac when I switch AC on and OFF there is a delay before it uses the AC input, why cant they simply put the unit "really" off grid when the solar is really good?

I would appreciate any advice / feedback from this group, it looks like a nice community here.
One unimpressed SW4048 owner.......

Justin

Dave Angelini · May 2022

Feedback = firmware on all devices up to date? Your battery math for AH looks wrong to me. The smaller battery can cause the inverter to not balance loads, but it will always be an issue with a 4KW inverter. Too small !

There is alot of info on the forum here if you search it. This is really a job for an XW that does not get imbalanced by L1 and L2 loads.

enginerd · May 2022

You are right on ah. Only 150ah
I have not updated firmware but have a build data from Dec 2021 my understanding is that I need a com box or other service tool to do the firmware.

Schneider Electric Conext SW 4048 Hybrid Inverter with AC Support multiple problems

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