Cost effective backup system, with future solar

Dave Angelini · January 2018

Yep and you are in the specific reason range that I would do this for. A technical and skilled user that has time to run the system. There are far too many that do not have time to even monitor, let alone make the adjustments you do. A generator often is hard to beat with the grid.

MrM1 · January 2018

The AC support works very well on a CSW if you have large loads and large solar input. ...

If you have small loads in daytime support mode, you will be unhappy with either the Outback or Schneiders products.

IMHO ... the CSW does not operate as advertised or stated in the owners manual. Even if one factors in the foot note in the manual that says CSW will always draw 2% from the grid in AC support mode, my system is not drawing 15% of the needed power from the batteries. From what I have seen, Schneider's AC Support mode is more like "Battery Supporting AC" rather than AC supporting battery.

Here I am with a small load at 93% SOC on my CSW 4024. L1 had 1.5 amps AC / L2 had .5 amps AC. Here you can see the SW is pulling less load off the battery than it takes to power the SW in idle state (38 watts)

(Also Note, I am on grid power. I do not know why the combox is reporting generator, and their is no setting that will take for changing it. I do not know how to get the display to show i am on grid. I am not connected to a gene and do not have one connect thru the SW. )

Image: https://us.v-cdn.net/6024911/uploads/editor/ui/bivxqqxin5lz.jpg

Here it is with a 120v 1100watt Water heater element added. L1 had 1.1 amps AC / L2 had 8.5 amps AC

And here is the system now adding in a well pump. I used to have my pump and water heater element on opposing legs, (spread over L1 and L2) and it worked better ... but at the moment I have the loads mostly on L2. L1 was at 1 amps AC / L2 at 15 amps AC. next week I am moving the water pump to 240VAC and then the pump load will be spread between L1 and L2 at about 4 amps AC per leg. But the system still will not work well in AC Support mode hour to hour as the then balanced well pump only runs a total of about 2 hrs a day spread over 24 hours. (btw my full size fridge is on L1 running 24/7 at about 150-350 watts per hour.

Image: https://us.v-cdn.net/6024911/uploads/editor/eh/i933e0doosy4.jpg

As you can see ...
1. AC support does NOT work and Schneider said this was how the system was designed and was working normally. They did testing for me on their end and sent me work to do on my end all thru Nov 2017. They came back and said, for it to work, loads on the SW must be balanced.
2. If I do balance the loads, it will indeed pull about 75% off battery and 25% off the grid. BUT it only kicks in over 1200 watts total. And only if the loads are nearly balances. My normal hour to hour loads are about 300 and lower when sleeping.

But 1200 plus watts is a large load and and who can guarantee balanced loads 24/7? And who has the battery and money to run huge loads off battery for extended periods of time ... but if I use balanced large loads, it works more or less for the few minutes all the conditions are met.

But in my opinion, AC support mode does not work as stated in day to day, hour to hour use. And the CSW's Load Shaving Mode works exactly the same as AC support mode. I do not know if other brands work better, but Schneider's version of AC Support mode (or Zero Grid as it is called by others brands) does not work right at all according to the way it is promoted in the SW inverter. So if using battery power during peak cost times (load shaving) or using battery until a specific low voltage or SOC is reached to save money on power by supporting gird use is your goal .. you'll need to look else where, the Schneider Conext SW series does not deliver.

Dave Angelini · January 2018

All I can really see is it does not work for you!

You should call Schneider or get professional help for what you have bought.

My only tip to you besides what I have tried to do here is say, that the Support mode depends on data from the Schneider mppt to work correctly. The solar input is what triggers the mode.

PeteS · January 2018

I appreciate all of the feedback. I probably should have titled the thread something a bit different than "Cost effective backup...", since the cost effective part was relative to a number of factors. I never intended for it to be as inexpensive in the long run as just having a generator for backup. I have an old Yamaha 2800W generator with 1000+ hours on it, which is now quite noisy. I like the idea of having an alternative electrical source, which is silent (or close to silent) and kicks on instantly. I don't mind running a generator to supplement a solar system during an extended outage, but I don't want to listen to a generator running 24/7.

Speaking of generators, the gas vs. propane argument does not favor propane in my area, not this winter anyway. I use propane as my sole heat source at the moment. I am on automatic propane delivery, based on degree days; they're supposed to delivery without me calling and I should never run out. Going into a very cold stretch two weeks ago, I called when my 120 gal. tank got below 20% to make sure they would be coming the following week. Then I called Wednesday and Thursday when they didn't show up, as they said they would, and was told they would be here Friday. When I called Friday afternoon they said they were sending a truck out. I ran out Friday night in temps around 0F and was trying to keep my house warm with my electric oven. So, I don't have much faith in a guaranteed supply of propane for generator backup. Yes, I will be finding a new propane supplier in the spring.

Estragon · January 2018

In fairness to the propane supplier, it's been unusually cold in a lot of North America recently, and as I understand it, propane distribution doesn't have as much capacity to respond compared to natgas, for example. Not an excuse, but maybe a reason. They should at least have been up front about any supply issues.

Personally, I wouldn't rely on propane as a sole source of heat unless I could store close to a winters worth. Even then, I'd want a wood/pellet stove. Whatever else breaks, I know that will work. As a generator fuel though, propane does have advantages in terms of long term storage compared to gasoline or diesel.

MrM1 · January 2018

Dave Angelini said:

All I can really see is it does not work for you!

You should call Schneider or get professional help for what you have bought

I spent hours on the phone with Schneider. After a month of testing on their end (that they did) and them sending me test equipment to test on my end, the engineers told me it was operating as designed and that the way grid interaction as stated in the manual is incorrect for voltage and/or SOC operation. (Schneider Tech Support words, not mine)

I was merely suggesting the OP realized that various hybrid inverters may or may not live up to their exact claims of load shaving and grid interactivity in every set up and noting that - in my experience and conversation with Schneider - the SW Inverter may or may not do what the OP is looking for. Also As BB also expressed ...

BB. said:

I would never suggest installing a full Hybrid (GT+Off Grid hybrid) AC inverter + battery bank system to save money if you have utility power.

And I was agreeing with that idea as I have found they don't always work as claimed. Thus, for the OP, it might be better to know some other peoples real world experiences before, rather than after a purchase.

Dave Angelini · January 2018

You need a Schneider charge controller for this to work! I can't believe they did not tell you this! Look at the difference in my screen shot and yours. The solar data is from the xanbus and needs to be a Schneider to work.

Image: https://us.v-cdn.net/6024911/uploads/editor/uj/p5uz40jdc3s2.png

MrM1 · January 2018

Dave,
While i do respect your knowledge and reputation on this forum (and most likely will need your wisdom sooner than later), they way I read the SW manual, there are 3 different user set conditions that will engage AC Support mode. The User selects one of the 3
1. Voltage of the battery bank. When the battery is above the user set threshold AC support mode is on and the system will draw no current from the grid. (then a foot note says "To prevent injecting current into the grid from the inverter, there is less than 2 amps of offset allowed from the grid" at all times). This Mode requires no other Xanbus device in the system - But as noted above ... it does not work as described in the manual
2. SOC of the Battery bank. Requires a Xanbus enabled batter monitor. Also does not work as describe. I have a battery monitor sent to my by Schneider for testing because #1 was not working.
3. Enhanced AC Support which does requires an MPPT controller. I cannot test this as I do not have the Xanbus CC.

And actually there are 4 options if you bring in Load Shaving
4. Load shaving. Is set by a time block (user defined) and a current limit setting for limiting current from the grid during the time block. It requires no other Xanbus devices. In my limited experience, the SW's load shaving works exactly the same at 1 and 2 as far as grid interactivity is concerned. It only works if the loads are balanced and the about 1/2 of the total wattage of the inverter.

Under 1000 watts and my system pulls off the grid almost completely balanced loads or not. Get it up to 1500 or more watts, and balance the loads, and it will pull almost exclusively off battery/solar. But this is not how it is stated, and can become very frustrating to 1.) balance the loads all the time and 2.) get the load hi enough to actually have AC Support mode / Load Shaving see any grid interactivity savings.

Please correct me if I misunderstand this, but from my experience and conversation with Schneider 1, 2 and Load Shaving do not work as stated in the manual. And was told by Schneider, the way it is expressed in the manual is incorrect, and that my SW is doing what it is supposed to do. 1 and 2 do work in the SW, but only if the loads are reasonably balanced and significantly hi. I mention it hear because in early Jan the OP was thinking of getting an SW for grid interactivity. Part of my reason for purchasing the SW was grid interactivity ... and I have been very disappointed in this aspect. This info may or may not impact the OP's purchase.

Dave Angelini · January 2018

I have zero experience with number one because I would never use a system with different makes of equipment. The web portals from Outback and Schneider give all the data anywhere in the world.

If you had the battery monitor or if it was wired correctly you would see a Soc reading like I have in my screen shot.

For 500$ you could get the MPPT and do #3. I really only have done #3 for clients as I have already said.

Make sure your SCP is up to date! The advanced features that you are using in CSW show an update from november 2017.

Become a client and you will not be able to stop me from talking

mcgivor · January 2018

@MrM1 said, 3. Enhanced AC Support which does requires an MPPT controller. I cannot test this as I do not have the Xanbus CC.

Could this be the root cause of the issues, not a complete system? All components need to communicate, one missing link corrupts all other functions?

MrM1 · January 2018

mcgivor said:

@MrM1 said, 3. Enhanced AC Support which does requires an MPPT controller. I cannot test this as I do not have the Xanbus CC.

Could this be the root cause of the issues, not a complete system? All components need to communicate, one missing link corrupts all other functions?

I don't think so as the SW is designed to work with their CC (option #3) or without their CC (options 1 and 2).

The inverter does work. And actually does a very good job of inverting. It just does not seem to do a good job with grid interactivity (I guess unless you have all Conext devices). I like all the user control features, and the 240 split was probably the main reason I bought it. I am developing work around habits and setups to over come my frustration with grid interactivity. I plan to run my breaker for AC In to inside my house so I can switch it on and off without having to make a trip to the "control center".

Dave ... Yes I have all the latest firmware in both the SCP, and the SW. And sorry, the pics I took are after I took the battery monitor out of the Xanbus (after testing). The battery monitor failed about 10 days ago and stopped showing up in the Xanbus in the Combox display. I am trying to get it replaced. There is also the possibility I have a bad SW. But as of yet, Schneider is not saying so. Still working with them.

Cost effective backup system, with future solar

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