Schneider XW Pro Multi Inverter Setup Limits

[realpinochet]

Thanks for the comprehensive post; it seems like what you're saying is if it's more than two xwpro inverters and not just two? I'll have to reread this latter. In the meantime I asked the same question on the outback forum and they seem to think it's a Schneider issue. Seems like this is a space where the solark 15k shines.

When using two or more GS8048a inverters ..relay question - OutBack Power Technologies User Forum

forum.outbackpower.com

 

[Darcy Costa Rica]

The internal relays are electro/mechanical. During a grid fail/disqualify, these relays open and switch to invert mode. Obviously the relays have maximum current limitations. Relays use magnetic energy to close and springs to open. A typical Schneider Tesys D DT60A 60A contactor has an advertised closing time 12-26ms and opening time of 4-19ms. Due to the large variation in opening time due to spring constants being different, multiple paralleled relays do not open at the exact same time. Each relay has a maximum continuous current rating and also a maximum current breaking rating. Due to the staggered opening times, it is technically possible, under a worse case scenario that a single relay would be burdened with breaking more current when opening than its rating. If this scenario happens, the relay contacts would not break open, would weld themselves shut, and then would backfeed inverter battery output power to the grid. There is no double failsafe, only a single relay. What you have to understand is relay contacts are arcing while opening under load, the arc starts as they open, then quench/extinguish as they open fully. This contact material is designed to "clean" itself due to this arcing and also withstand the arcing/quenching of the arc. If a contact is being subjected to breaking currents in excess, it simply will weld due to the temperatures at the contact surfaces, exceeding the design limits and melting instead of cleaning/opening like normal. Due to 60Hz having a 16.666ms period, a difference of this amount of time between all contactors opening would easily force a single relay to carry 3X the breaking current for an entire cycle, while opening, in a 3 inverter setup. This is why they state 3 or more require an external transfer switch.

Inside the XW the relays are soldered onto the board and not easily replaceable. Outback either ignores this reality or uses larger relays with a higher rating. I believe in the radian, they are mounted in such a way to allow easier changing than Schneider. I believe the Radian relays are soldered in also, but is a faster swap. Cant remember.

I can tell you that the XW units 3 or more is a huge bummer due to loss of features when using an external contactor, switch, or BCS unit. There is additional cost for this hardware that is far cheaper than having a welded relay backfeed a line and violate UL listing and potential hurt a lineman. Backfeeding the grid is impossible with such a small inverter, but under a worst case scenario, could energize a small section of power lines and kill a lineman let alone damage your equipment.

The Schneider BCS unit is essentially a whole house transfer switch. It does the heavy switching instead of the internal relays. You loose generator inputs and UPS style functionality. AC coupling is also more tricky,

Using 3 or more XW's is possible without such additional hardware, it will work, but not from a manufacture manual, reliability, technical position. If inspected and found, you would be in violation of the manufactures instructions, with is a NEC violation and would be shut down/red tagged by the POCO. Most POCO's know the UL1741 standards, which manufactures comply, and how they work. Some POCO's go as far as approved inverter list. Not all POCO's are super thorough, they simply look for UL1741 approvals when doing reviews.

Thank you for the excellent explanation of the problem that having multiple inverters can cause. I have a couple of questions that I think you may be able to help me with.

First, if you have two inverters, and your potential load was more than 60 Amps, couldn't they have the same problem? Couldn't the relays still try to carry the current in an unbalanced way creating the same overload/welding failure?

Second, if I am only planning on using the Grid for emergency battery charging, is it possible to set up the XW Pro so it never attempts to power the backup loads panel through the Grid? If this is possible, there should never be relay switching from PV to Grid and back.

I am going to write up my scenario and, in a new thread, ask for assistance on the best way to configure the inverters.

Thanks again.

 

[realpinochet]

Thank you for the excellent explanation of the problem that having multiple inverters can cause. I have a couple of questions that I think you may be able to help me with.

First, if you have two inverters, and your potential load was more than 60 Amps, couldn't they have the same problem? Couldn't the relays still try to carry the current in an unbalanced way creating the same overload/welding failure?

Second, if I am only planning on using the Grid for emergency battery charging, is it possible to set up the XW Pro so it never attempts to power the backup loads panel through the Grid? If this is possible, there should never be relay switching from PV to Grid and back.

I am going to write up my scenario and, in a new thread, ask for assistance on the best way to configure the inverters.

Thanks again.

The manual on page 25 has the various setups and it does say two inverters without all the external stuff is supported. I'm not sure why over two brings all this into play.

https://solar.se.com/eu/wp-content/uploads/sites/4/2021/08/XW-Pro-Multi-Unit-Design-Guide_990-91373.pdf

Also, over at the outback forum I posted above users are saying they never seen this requirement for radians. Have you considered a outback? While I don't have experience with either one from what I've read and been told the radians are battle tough and reliable. I had a installer tell me that the xwpros are dam near unbreakable but that the radians are almost the same. Seems like people like the raidan software better to.

Outback Radian GS8048A-01 8,000 Watt Advanced Inverter/Charger

Note: This item is delayed indefinitely, please contact us for alternative options. NOTE: The OutBack Power Radian inverter is not designed for use in mobile applications and will void the manufacturer’s warranty. If you need a large mobile system, it can be custom built as a power panel that...

www.solar-electric.com

 

[Darcy Costa Rica]

The manual on page 25 has the various setups and it does say two inverters without all the external stuff is supported. I'm not sure why over two brings all this into play.

https://solar.se.com/eu/wp-content/uploads/sites/4/2021/08/XW-Pro-Multi-Unit-Design-Guide_990-91373.pdf

Also, over at the outback forum I posted above users are saying they never seen this requirement for radians. Have you considered a outback? While I don't have experience with either one from what I've read and been told the radians are battle tough and reliable. I had a installer tell me that the xwpros are dam near unbreakable but that the radians are almost the same. Seems like people like the raidan software better to.

Outback Radian GS8048A-01 8,000 Watt Advanced Inverter/Charger

Note: This item is delayed indefinitely, please contact us for alternative options. NOTE: The OutBack Power Radian inverter is not designed for use in mobile applications and will void the manufacturer’s warranty. If you need a large mobile system, it can be custom built as a power panel that...

www.solar-electric.com

They are mounted on the wall. Too late for those kind of thoughts.

 

[eleceng1979]

First, if you have two inverters, and your potential load was more than 60 Amps, couldn't they have the same problem? Couldn't the relays still try to carry the current in an unbalanced way creating the same overload/welding failure?

Second, if I am only planning on using the Grid for emergency battery charging, is it possible to set up the XW Pro so it never attempts to power the backup loads panel through the Grid? If this is possible, there should never be relay switching from PV to Grid and back.

1. Answer to first Q. Probably not. A relay's continuous current rating is X, its breaking current rating is typically 2-5X (depends on manufacture datasheet). So assuming you had 2 XW's, operating in AC passthrough of 120A load (60A each), had a grid down scenario, both XW relays open, inverter would output a max of 104A (52A Each) and loads would not drop, this is 100% acceptable per the Schneider manual. It is an allowed configuration per their multi unit specs/manual.

2. Answer to second Q. Yes, but not how you explained. The inverter is bidirectional to/from all energy sources. This is the hard part to understand. See the picture below of the functional power block (user manual pages 24-26). If at any time AC1 OR AC2 relays are closed, it CAN power the loads based upon the operational modes programed. To answer your question fully, the XW can operate in "Grid Support" mode (user manual pages 80-83) and if properly configured, can provide exactly what you want (only use AC to keep batteries up and to not power loads directly). Understand, it could only do this based upon parameter settings and there will be some AC grid current at all times no matter what, a few watts best case scenario.


Understand, the XW allows unlimited configurations due to the many parameters. Most people/installers get them set incorrectly and the units behave incorrectly, and they get a bad name/reviews/bashing. The XW is really an engineers wet dream, not a DIY 1 button configuration. I am not partial to either XW or Radian. I believe the XW to be a better product due to the ecosystem of accessories and level of integration. Not to mention it is Schneider electric which is not going anywhere. The Con is you pay for it $$$. The Outback Radian solution is equally comparable. In my eyes, their ecosystem/software is not as polished, but offers higher total output KW, but less surge KW/to full KW ratios as the XW. Both are LF inverters, the top of the food chain from each, and both are winners. As an EE, with OCD, I find the minor differences between the two.

In regard to the 3 or more unit requiring external relays. Schneider has taken the upfront, visible analytical approach as said, if 3 or more XW's used, the probability of failure has risen due to the reduction of lifespan, which increases liability due to welding failure, reduces lifespan of the relay/inverter, increases warranty cost, and carries risk associated to UL listings/possible back feed, and therefore we suggest using an external contactor. Understand no company who makes relays for a living is going to say that it is ok to operate outside its datasheet specifications. The datasheet has specs for everything, including lifespan. The XW is an old design, from Xantrex, carried over to Schneider. The market really needs 200A internal bypass ratings like the Sol-Ark 15K, but minus the other firmware/HF inverter headaches, I digress.

What you/everyone is missing is that Radian has an identical limitation, but goes unnoticed. Per the Radian installation manual, when using 2 or more (up to 10), you cannot enable Grid Support or Grid Zero modes. These modes would close the internal transfer relay all the time, and it would be subjected to the same exact scenario as the XW that I have described previously. Radian does not come out and tell you "NO! Don't do it" like XW, they bury the comment in the installation manual, that is a tiny footnote, that references the user manual. XW clearly calls it out and says NO. The exact reason why Radian says no to these 2 modes of operation is exactly the reason XW says you cannot do 3 or more units in parallel without an external bypass contactor. It is Radian marketing of saying "look, we can do 10 in parallel!". Both inverters are subject to the same restriction, yet one manufacture is up front about it. Read page 41 Important footnote of the radian installation manual.

"Do not use the AC input modes Support or Grid Zero in a stacked system. See the Operator’s Manual."

FYI, I am not affiliated with NOR rep either brands. I simply provide custom solutions that work.

 

[realpinochet]

1. Answer to first Q. Probably not. A relay's continuous current rating is X, its breaking current rating is typically 2-5X (depends on manufacture datasheet). So assuming you had 2 XW's, operating in AC passthrough of 120A load (60A each), had a grid down scenario, both XW relays open, inverter would output a max of 104A (52A Each) and loads would not drop, this is 100% acceptable per the Schneider manual. It is an allowed configuration per their multi unit specs/manual.

2. Answer to second Q. Yes, but not how you explained. The inverter is bidirectional to/from all energy sources. This is the hard part to understand. See the picture below of the functional power block (user manual pages 24-26). If at any time AC1 OR AC2 relays are closed, it CAN power the loads based upon the operational modes programed. To answer your question fully, the XW can operate in "Grid Support" mode (user manual pages 80-83) and if properly configured, can provide exactly what you want (only use AC to keep batteries up and to not power loads directly). Understand, it could only do this based upon parameter settings and there will be some AC grid current at all times no matter what, a few watts best case scenario.
View attachment 142597

Understand, the XW allows unlimited configurations due to the many parameters. Most people/installers get them set incorrectly and the units behave incorrectly, and they get a bad name/reviews/bashing. The XW is really an engineers wet dream, not a DIY 1 button configuration. I am not partial to either XW or Radian. I believe the XW to be a better product due to the ecosystem of accessories and level of integration. Not to mention it is Schneider electric which is not going anywhere. The Con is you pay for it $$$. The Outback Radian solution is equally comparable. In my eyes, their ecosystem/software is not as polished, but offers higher total output KW, but less surge KW/to full KW ratios as the XW. Both are LF inverters, the top of the food chain from each, and both are winners. As an EE, with OCD, I find the minor differences between the two.

In regard to the 3 or more unit requiring external relays. Schneider has taken the upfront, visible analytical approach as said, if 3 or more XW's used, the probability of failure has risen due to the reduction of lifespan, which increases liability due to welding failure, reduces lifespan of the relay/inverter, increases warranty cost, and carries risk associated to UL listings/possible back feed, and therefore we suggest using an external contactor. Understand no company who makes relays for a living is going to say that it is ok to operate outside its datasheet specifications. The datasheet has specs for everything, including lifespan. The XW is an old design, from Xantrex, carried over to Schneider. The market really needs 200A internal bypass ratings like the Sol-Ark 15K, but minus the other headaches, I digress.

What you/everyone is missing is that Radian has an identical limitation, but goes unnoticed. Per the Radian installation manual, when using 2 or more (up to 10), you cannot enable Grid Support or Grid Zero modes. These modes would close the internal transfer relay all the time, and it would be subjected to the same exact scenario as the XW that I have described previously. Radian does not come out and tell you "NO! Don't do it" like XW, they bury the comment in the installation manual, that is a tiny footnote, that references the user manual. XW clearly calls it out and says NO. The exact reason why Radian says no to these 2 modes of operation is exactly the reason XW says you cannot do 2 or more units in parallel without an external bypass contactor. It is Radian marketing of saying "look, we can do 10 in parallel!". Both inverters are subject to the same restriction, yet one manufacture is up front about it. Read page 41 Important footnote of the radian installation manual.

"Do not use the AC input modes Support or Grid Zero in a stacked system. See the Operator’s Manual."

FYI, I am not affiliated with NOR rep either brands. I simply provide custom solutions that work.

Thanks for the input. What's interesting is I posted these questions on the outback forum and I've had a few people there tell me they've never seen this as a issue on the radian inverters and some have three or more radians setup and have never had issues. The specs on the relays in the 8048a is 50A even smaller than the 60A for the xwpro. I wonder why the radian doesn't suffer from this?

 

[eleceng1979]

Neither XW or Radian will "suffer" from such wear/tear/reduced lifespan on the transfer relays, UNLESS they are constantly subjected to maximum currents being pulled across all relays. Meaning, if 3 inverters, at 50/60A each, pulling 150/180A across the relays, opening all the time, would result in such a failure eventually. You can use 3+ of each inverter, paralleled for years, without issue as "most" use cases never pull such high loads. An average 200A service at a house, never sees anywhere near the 200A rating. It simply is a ratings/compliance issue. If the constant currents exceed 2X the relay ratings I would be worried. They only suffer when breaking the current/opening the relays.

I know of several 3+ unit setups working fine without such precautions taken. It is just technically wrong per the manual. Another approach is to derate the incoming AC power service. e.g. take a 200A service main breaker down to 100-125A coming into a 3+ inverter setup. Then configure the inverters to not use more than 100-125A (summed) service which keeps the inverter setups legal per the relay restrictions.

UL/NEC states that equipment must be used per manufacture instructions. These non-compliant setups would be in violation of the UL/NEC and not pass an inspection. Most inspectors are not detailed enough to catch it. Let alone installers being liable for them. I am not advising of improper usage, I am just stating that it can be done improperly. Just because it CAN be done, does NOT mean it SHOULD be done...

 

[wheisenburg]

Hi, I'm trying to install 3 Schneider XW Pro inverters. It seems there is a warning about using 3 of these that I do not understand. Are there any Schneider Experts out there who can explain where the problem is when using 3 inverters? This is the quote from the installation manual:

EQUIPMENT DAMAGE

• The Automatic Transfer Relays are rated at 60 A.
• Loads connected at AC OUT must not exceed the inverter's overload ratings or the 60 A limit, whichever is lower. Unless an external contactor or external transfer switch (such as the Schneider Electric BCS) is used, the 60 A limit also applies to the total combined loads connected to the AC OUT bus of multiple inverters connected in parallel.

The electricity is so bad here in Costa Rica, I am planning on using the inverters to power my house all the time, and only using the grid for charging the batteries if the sun does not shine enough during the rainy season. So, I do not expect to be transferring from the grid to PV and back due to power outages.

I have installed a 200 Amp Eaton transfer switch that I will use when servicing the inverters. Otherwise, the property will always be powered by the Schneiders. With over 20 KW of power from the 3 inverters, I do not think I will ever exceed their power.

Many thanks. I will be posting quite a few questions as I am finally starting to install my system. Totally DIY.

As some other people on here have stated, the issue is a limitation with the relays that switch between grid power and inverter power. It seems here like you are not aware of the fact that if you put power on the AC1 inputs, the inverter will switch to pass through mode. So you will be switching your entire output from inverter mode to pass through mode. When you have grid power and are in pass through mode, it becomes possible to use the incoming power to charge the batteries. The inverter will then switch to "Charging" mode. These three modes are mutually exclusive.

Now if you truly want the inverter to always run in inverter mode, you can only do that by not putting power into AC1. Then the inverter will stay in "Inverting" mode. Of course the problem is then you can't use the charger in the inverter to charge the batteries. There are portions of the circuitry like the transformer and the FETs that are reused in both the Inverting and Charging operations. So you can't do both at once.

You may want to rethink this whole idea of running in inverter mode all the time. If this is something you really want to do then it seems like you could setup two dedicated inverters. These would never have AC power connected to them and would always draw their power from the DC system. Then make one of your inverters a dedicated charger. It would be connected to the grid on the AC input and would charge the battery as needed when grid power was available.

I assume you are also going to have charge controllers to convert solar to DC for charging the batteries? I looked through here and saw something about a PDP and charge controllers, but I didn't see where you said that. What is the Maximum load that you need to power? Remember the Schneider can do surges that are nearly twice their continuous rating. Something like 24,000 watts for a minute with two inverters. They can push 18,000 watts for 30 minutes. Will you really be exceeding that? Maybe some of these really large loads can remain on the Grid tied panel? For example an electric water heater.

The only good reason I see to do this would be to solve a power quality issue. The ability to quickly switch between pass through and inverting mode should handle power availability issues If you have voltage sags, frequency errors and other quality issues, then running in pass through mode while charging your batteries will not solve those problems. All that bad power will make its way into your house. As soon as the inverters see good power on the grid the inverters will shut down and pass that power in. If you want a system where your house oower is always coming from the inverters and is clean power, then that is what you need to design.

So why are you doing this and how much power do you really need?

 

[wheisenburg]

Per google.

200-amp service is the current standard for new homes and updated service panels. It can supply all standard electrical needs in a typical family home but may not support a large electric heating system. In large homes, 300-amp or larger service capacity may be needed, particularly if the home has electric heating.Nov 15, 2022

So, I assume they are saying 100A per leg is average in USA for split phase? This isn't correct?

Just an FYI,

Split phase power has three wires plus a ground. There is a L1, L2, and N. Voltages are:

L1 => N 120.
L2 => N 120.
L1 => L2 240.

L1 and L2 both have 120 volts to ground or neutral. They are 180 degrees out of phase (when one is plus 120 the other is minus 120). So when running a 240 volts circuit at a given number of amps, you get twice the volts and twice the watts compared with 120. The current flows from L1 to L2. If you are drawing 100 amps, you will have 100 amps on both L1 ands L2.

If you are on a 120 volt circuit like L1 => N, you will have 100 amps on L1 and 100 amps on N. L2 will have zero amps. Circuit comes from the word circle. What ever amps you are drawing it has to flow back to its point of origin. It flows out on one wire and back on the other. It does not get divided. With watts it is different. At 100 amps you are pulling 12,000 watts at 120 volts. At 240 volts you are using 24,000 watts.

We call this relationship between watts, voltage and current (Watts = Current * Voltage) Ohms law. It is the most fundamental law of electricity. If you are going to be advising people on this forum you might want to study up on it.

 

[wheisenburg]

I like to hear from folks that have two or more of these unites without the external switch and had issues with a normal residential house. Is this 60A per leg or 60A across the two ..so 30A each leg? I could see myself exceeding this in the winter with the Heater, dryer, oven and normal other stuff going. I forgot about this limitation! I wish they'd update these units to have 100A per leg like the new solarks.

I have two inverters. My power is very reliable here, so I don't have much switching between inverter and grid. I don't think I will ever exceed their 14,000 watt limit even momentarily. I got two inverters because I have more AC coupled power than a single inverter can handle.

 

[Darcy Costa Rica]

As some other people on here have stated, the issue is a limitation with the relays that switch between grid power and inverter power. It seems here like you are not aware of the fact that if you put power on the AC1 inputs, the inverter will switch to pass through mode. So you will be switching your entire output from inverter mode to pass through mode. When you have grid power and are in pass through mode, it becomes possible to use the incoming power to charge the batteries. The inverter will then switch to "Charging" mode. These three modes are mutually exclusive.

Now if you truly want the inverter to always run in inverter mode, you can only do that by not putting power into AC1. Then the inverter will stay in "Inverting" mode. Of course the problem is then you can't use the charger in the inverter to charge the batteries. There are portions of the circuitry like the transformer and the FETs that are reused in both the Inverting and Charging operations. So you can't do both at once.

You may want to rethink this whole idea of running in inverter mode all the time. If this is something you really want to do then it seems like you could setup two dedicated inverters. These would never have AC power connected to them and would always draw their power from the DC system. Then make one of your inverters a dedicated charger. It would be connected to the grid on the AC input and would charge the battery as needed when grid power was available.

I assume you are also going to have charge controllers to convert solar to DC for charging the batteries? I looked through here and saw something about a PDP and charge controllers, but I didn't see where you said that. What is the Maximum load that you need to power? Remember the Schneider can do surges that are nearly twice their continuous rating. Something like 24,000 watts for a minute with two inverters. They can push 18,000 watts for 30 minutes. Will you really be exceeding that? Maybe some of these really large loads can remain on the Grid tied panel? For example an electric water heater.

The only good reason I see to do this would be to solve a power quality issue. The ability to quickly switch between pass through and inverting mode should handle power availability issues If you have voltage sags, frequency errors and other quality issues, then running in pass through mode while charging your batteries will not solve those problems. All that bad power will make its way into your house. As soon as the inverters see good power on the grid the inverters will shut down and pass that power in. If you want a system where your house oower is always coming from the inverters and is clean power, then that is what you need to design.

So why are you doing this and how much power do you really need?

The reason for doing this is a) bad power and b) cost.

The power in our area can go on and off a dozen times per day. The quality is terrible, but without tools that is just subjective. Appliances fail with regularity. Electronics suffer. Although you can buy a UPS for your computer or TV, I have over 130 network devices in my house. It is a smart home. When complete it will probably have nearly 180 devices. Using a UPS, I cannot protect intelligent wall switches and smart relays inside electrical boxes from bad power. So, I chose Schneider. As I built the house I realized that I was actually trying to go off-grid with grid support only for charging the batteries during the rainy season.

I never thought I would need the power of 3 Schneiders, so the third is almost a backup in case one of the other two has a problem. Wiring as you suggested with one as a charger is interesting. My prediction is there will be enough solar power to charge the batteries each day. During the rainy season, I am often in Canada anyway, so the power usage drops by about half.

 

[DER Solar]

Great explanation of the relay arcing in a stacked setup with parallel connected relays. Applies also to Sol-Ark and LUX Power inverters and similarly stacked inverters.

Additionally, relays bounce on close 3-4 times before making permanent contact, increasing the stress on the relay contacts. The Deltron relays on the XW AC board are 3-phase/3-pole relays, but have all 3 contacts connected in parallel, one relay per split-phase line. Still, one of the 3 contacts in each relay will close first and one of the contacts will open last.

The BCS has a fully rated 200A MID relay with a built-in passive feedback contact, so it can signal the XW if it would be malfunctioning, a major requirement for MID fault detection. Gruner supplies the best MID relays in use at FranklinWH, Powerwall Gateway and many others. Have not yet had a chance to examine the relay in the BCS, but it looks like a Gruner or Gruner clone.

In a BCS setup, the XW control board provides the logic for MID operation and MID feedback and it needs to sense the Grid voltage. The AC relay board has no independent or decoupled Grid sensing voltage input ports, so SE came up with a work-around to use the AC2 Gen lines for grid sensing, sacrificing generator input use on the AC2 lines or for using AC2 lines for AC coupling like a Sol-Ark or LUX Power. The 2 relays in the AC1 lines stay closed all the time and support EPO disconnect if de-activated. The AC (load) lines are energized all the time when the inverter is active and are not used at all because there is no disconnect relay in these lines. An EPO would require an external relay and/or reliable shut-down of the inverter.

Only the master XW need to sense the grid voltage by using AC2 lines. With smart AC coupling, SE could potentially use the "unused" slave AC2 lines in a stacked setup for generator input or for hard PV on-off AC coupling.

 

[Nobodybusiness]

Curious if you house is all Electric? Is you're whole house wired into this inverter...AC,heater,oven,dryer and all the other junk like tv, microwave etc? I'm concerned about using multiple large appliances at once and it being a issue.

That’s why I went with Dual Sol-arks.
Have all electric house and shop.

I know Sol-Arks aren’t everyone’s cup o tea but they do work.

One of the reason why a I didn’t go with Schneider.
Was having doubts about total availability.

 

[EnderWiggin]

The reason for doing this is a) bad power and b) cost.

The power in our area can go on and off a dozen times per day. The quality is terrible, but without tools that is just subjective. Appliances fail with regularity. Electronics suffer. Although you can buy a UPS for your computer or TV, I have over 130 network devices in my house. It is a smart home. When complete it will probably have nearly 180 devices. Using a UPS, I cannot protect intelligent wall switches and smart relays inside electrical boxes from bad power. So, I chose Schneider. As I built the house I realized that I was actually trying to go off-grid with grid support only for charging the batteries during the rainy season.

I never thought I would need the power of 3 Schneiders, so the third is almost a backup in case one of the other two has a problem. Wiring as you suggested with one as a charger is interesting. My prediction is there will be enough solar power to charge the batteries each day. During the rainy season, I am often in Canada anyway, so the power usage drops by about half.

I'm looking at almost the exact same setup as you are, Darcy CR, for almost the same reasons - the power in Sint Maarten is not as off/on as your experience, but it is massively "dirty" - very square wave, evidently, and many of my clocks regularly lose at least 1 minute per day. Every electronics seller on the island warns you, repeatedly, to put surge protection, if not UPS, on everything.

We're building a villa that will be heavily "smart" - without an annoying digital spyware like Alexa listening in - and it has to be three-phase because that's the power on the island, so I will use three inverters. The idea you're turning me on to, whether we go with Victron or Schneider (leaning towards the latter), is an external Chargeverter just for charging batteries, and not even wire in the grid on the AC In side of things. That way there will never be any backfeed, and never any outage so long as the usage doesn't do beyond a Chargeveter's capacity (it won't).

Thanks for your, and others', posts on this, as the upcoming project (mid-2024) needs all the input it can get! Local installers on Sint Maarten aren't always very knowledgable, so I'm looking at DIY, and all this information is awesome...

 

[Scat]

That’s why I went with Dual Sol-arks.
Have all electric house and shop.

I know Sol-Arks aren’t everyone’s cup o tea but they do work.

One of the reason why a I didn’t go with Schneider.
Was having doubts about total availability.

@Nobodybusiness How does the Sol-Ark handle surges like a 3-ton ac no soft start or a air compressor?
Thanks
Scat

 

[Nobodybusiness]

@Nobodybusiness How does the Sol-Ark handle surges like a 3-ton ac no soft start or a air compressor?
Thanks
Scat

The 12K is different to the 15k and duals are different to singles.

I have dual 15ks and no issues whatsoever.

I never tried what you are suggesting with a single 12 or 15.

Depends on the LRA or surge of the compressor.

I can tell you this, 3 ton WITH a soft start my single 12k worked fine.
At the very beginning it was used as a backup when power went out.
We had a few instances where it ran the AC / House all night until power came back on.

 

[Scat]

The 12K is different to the 15k and duals are different to singles.

I have dual 15ks and no issues whatsoever.

I never tried what you are suggesting with a single 12 or 15.

Depends on the LRA or surge of the compressor.

I can tell you this, 3 ton WITH a soft start my single 12k worked fine.
At the very beginning it was used as a backup when power went out.
We had a few instances where it ran the AC / House all night until power came back on.

ok, thanks

 

[JBertok]

I run a dual XW Pro configuration and use the internal relays. I read about your smart home devices and the poor quality of power, and have observations from my own system.

When the grid drops it takes probably 100+ms for the XWs to throw the relays and switch to backup/inverter mode. It's too long for appliances, computers, or pretty much anything to stay running. When Schneider talks about how fast the XW's relays are, that's only applicable to a qualification/disqualification switch scenario. When it switches back from inverter mode to pass-through, for example, it's <10ms and none of the loads notice. If the XW's disqualify AC1 due to an over/under volt, over/under frequency, or anything else, that is also a <10ms switchover, and nothing will notice. So, your electronics will be protected from bad power by the XWs and their qualification criteria, but none of that stuff likes being power-cycled as they absolutely will be in the event of a grid failure.

I think that unacceptable delay is going to happen with an external contactor too because it's not the relays or contactor making it take so long. The XWs have to switch from referencing grid waveform to producing their own waveform (backup mode) while at the same time providing enough margin of time to the relays to make absolutely sure they've cut off AC1 to prevent feedback before inverting.

Faced with your situation I might be looking at running a pair in Primary/Secondary, and then running the third one in Stand-Alone, basically off-grid with no grid input so it's in Inverter mode all the time, and attaching my critical loads to a panel off of that one. I am not sure if that would need it's own Insight... never tried that.