Need some help with xw pro wiring.

[Joe_]

I’m confused. I have an XW Pro that I am trying to figure out how to use and get the most out of it. .
I can’t sell to the grid in my location it's not allowed and at this point I’m not intending to go off grid.

The main function of the system I am assembling is to backup a couple of freezers and a couple of fridges and a small AC if I am away in the summer.
That is the one thing it must do reliably. I am going to put those loads on a critical load panel and take advantage of the internal transfer switch . I am ordering a full size PDP with a bypass breaker for the bypass functionality and the possibility of adding a second inverter in the future. I think I have that portion of my problem sorted out. But if it sounds like I don't please let me know.

I also have a large, separate air conditioning load where I am assembling this system. When I am home I would like to feed this load from the PV’s through the inverter for about 4 hours a day during peak sun and peak outside temperature to lower my electric bill.
I am not certain how to wire that in to this system? I need that AC to run from the grid power most of the time. It pulls 4kw when it is hot out and it runs at an 80% duty cycle when temperatures reach110 degrees f.. Had a lot of those hot days this summer. My neighbors and I power bills have been quite a bit higher due to surcharges this summer.

To include the ability to run this load off my system do I need a manual transfer switch?, where I turn on the bypass breaker on in the XW PDP to keep the critical circuits panel heated up, then use a manual transfer switch to switch the AC off from grid power to a separate circuit from the AC side of the XW? Or is there a better way?

The one inverter I presently own doesn’t have enough capacity to reliably run both the backed up refrigeration loads and the large AC load at the same time. It’s one or the other. Because of that I don't think I can feed the large AC load off the critical load panel.

I’m planning my electrical panels,wire runs, and conduit runs right now and this issue has me at a standstill.

I have read the manual a few times and parts of it several times. I don’t really grasp Grid Support mode and Peak Load Shaving. It sounds good but without a second inverter I don’t think I have the capacity to power the combined loads of the large AC and backed up refrigeration. I don’t see that either function will help me in my situation. Am I overlooking or misunderstanding the manuals?



Thanks.. Joe

 

[BentleyJ]

Based on the above description which is missing some important info. It seems like you may be trying to solve a problem that does not exist. The beauty of the XW Pro is the built in Grid Support features that you mentioned as well as its ability to seamlessly transition from Pass-Thru to Peak Load Shave WITHOUT adding all the aforementioned manual transfer switches and various other electrical hardware.
1) What is the total load? The A/C is 4kW and there were a couple of freezers and refrigerators. Are these large commercial appliances with high current needs? Surge loads can easily be handled by adding a soft starter to the A/C compressor(s).
2) The XW Pro is capable of supporting up to 8500W for 30min and short excursions up to 10kW. (temp dependent)
3) Is the XW Pro inside in a somewhat cooler area than ambient of 110 deg? This is important because it impacts the output rating of the inverter since it will self derate above a certain temp. so full performance is not available beyond a certain temp. I believe the derating chart is in the manual.
4) Even if the total load with all the appliances is slightly higher than the capacity of one inverter, you can simply set Load Shave Amps & Sell Back-Zero Export to the appropriate values which will let some utility power slip through and you should be able to reasonably achieve the stated goals. Although, its worth mentioning the Schneider firmware is not completely bug free with regard to Enhanced Grid Support functions at this moment. BTW do you have Schneider charge controllers on the Xanbus network?

 

[400bird]

Great points by BentlyJ.

The one question I have is, are you moving that giant AC to the back up loads panel or leaving it in the main panel? It may be too large for the XW to start if it pulls 4kw running.

Is the manual transfer switch to move the large AC from critical to main panel depending on what you want to power that AC unit?

The better option, in my opinion, would be to run the Watt Node meter in the main panel. This measures grid current and allows the XW to offset any grid power usage. So, when the big AC is on, the watt node will measure the load and allow the XW to power that load by backfeeding the main panel, without backfeeding the grid.

Here's Schneider's document about connecting the watt node

 

[Joe_]

Thank you for your replies. I sincerely appreciate your time spent helping me.
I left a lot of information off because this a prototype system to figure out what I actually need. Not what I am finally building.
The high ambient temperature here in the summer has a lot to do with my choice to proceed in this fashion.

Based on the above description which is missing some important info. It seems like you may be trying to solve a problem that does not exist. The beauty of the XW Pro is the built in Grid Support features that you mentioned as well as its ability to seamlessly transition from Pass-Thru to Peak Load Shave WITHOUT adding all the aforementioned manual transfer switches and various other electrical hardware.
1) What is the total load?

In the summer on a 110 degree day my loads are this:
Critical loads:
The container which is a critical load because it cools the batteries and inverter draws 2 kw @ during high sun hours of 12pm-4pm.
It's cooled by a 2 ton mini split set at 79 degrees for the testing. In a 24 hr period (cool night /hot day ) it uses 15kw.
For this previous week it used 66.1 kw in the test . But there was no normal heat load from opening the doors or running a 90 ish efficient XW pro. during this time. Nor was there solar panels on the roof yet to provide additional shade to the container. These will change the amount of power required.

The freezers, fridges, pull 600 watts except during defrost cycles. Each fridge runs about 500 additional watts for a defrost cycle.
The 5000 btu conventional ac for a cold room uses 550 watts runs for 2.5 minutes of every 10minutes during from 10-6 hottest part of the day and less often as the temperature goes down in the evening. The refrigeration loads would change dramatically if the grid power actually went off and the interior of the house rose to a constant 105 f of course.


Non critical load, what I would like to run, or assist, off of solar intermittently when I have grid power to run my critical loads and I am home to supervise:
The house AC. A 5 T draws 5kw during it's at peak load at 110f . It runs 80 minutes of every 100 minutes during that period of time.
It uses ~4 kw if the temperature is between 100 and 110. Yesterday I installed a small 10,000 btu inverter window unit to help share the load.
I haven't done a load study on it yet. I am not concerned about running that unit off of solar. But the larger unit would be nice.

3) Is the XW Pro inside in a somewhat cooler area than ambient of 110 deg?

This is important because it impacts the output rating of the inverter since it will self derate above a certain temp. so full performance is not available beyond a certain temp. I believe the derating chart is in the manual.

Yes for this build it is in an insulated container with a 2 Ton mini split. However the container air conditioning was sized to rapidly (1hr) cool the container from 120 f on hot days when I need somewhere out of the heat to work on projects that can't be brought in the house.

The AC wasn't sized nor the container insulated for maximum efficiency.
I can't build an efficient cooled space until I measure the btu the equipment puts out and the cubic feet it requires. Catch 22.

Once I get the system operational I will be able to better access the actual heat load and determine what I have VS what I need.

4) Even if the total load with all the appliances is slightly higher than the capacity of one inverter, you can simply set Load Shave Amps & Sell Back-Zero Export to the appropriate values which will let some utility power slip through and you should be able to reasonably achieve the stated goals. Although, its worth mentioning the Schneider firmware is not completely bug free with regard to Enhanced Grid Support functions at this moment. BTW do you have Schneider charge controllers on the Xanbus network?

No I do not have Schneider charge controllers.

At present I don't really have sufficient PV either. I have approximate 5kw. But the more I can shave off my power bill with what I am presently assembling the more money I will be able to put toward upgrading. I have yet to begin installing the PV I own. It's too hot at present to do so.
It will shade the container that has the inverter and batteries in it part of the day and that will change that dynamic also.

I hope what I wrote isn't too confusing. The high temperatures really complicates things.

Great points by BentlyJ.

The one question I have is, are you moving that giant AC to the back up loads panel or leaving it in the main panel? It may be too large for the XW to start if it pulls 4kw running.

Is the manual transfer switch to move the large AC from critical to main panel depending on what you want to power that AC unit?

The better option, in my opinion, would be to run the Watt Node meter in the main panel. This measures grid current and allows the XW to offset any grid power usage. So, when the big AC is on, the watt node will measure the load and allow the XW to power that load by backfeeding the main panel, without backfeeding the grid.

Here's Schneider's document about connecting the watt node

I'll read the document. Thank you. Where do you find documents like this from Schneider? I looked for more information but came up empty.

 

[Joe_]

In the immediate future I hope to get enough solar up to power the 2 Ton ac that cools the container that the batteries I am about to buy will be mounted in. That is my first priority. I'm buying 28 k of batteries which would arrive in a month. It will be October and cooling cost will be going down but will go high again in April when I would like to have the XW up and running with enough solar to cover the cooling of the container for next summer.

I also need a good idea of what I am going to end up power wise at the end. I need to purchase wire to run the last 100 ft from a junction box outside of one container to the house critical and main load panels. I'd like to buy that wire once correctly sized for the end system and the correct number of circuits. Don't want to have it pulled twice since I am unable to pull it myself and must arrange for help.

 

[JBertok]

The bypass function provided by the breaker lockout toggle in the PDP is intended to power the critical load panel from the grid when doing maintenance on the XW. Firmware updates, for example, require that the XW is in standby mode, and take 15 minutes to install.

It sounds like the single XW Pro is enough to power everything you've got except the 5-ton AC system - but that's only relevant if you're inverting from battery/solar where you have those limits.

Consider this: put everything on the critical load panel - including the 5-ton AC unit. When the batteries are low and there is no PV it will be running in Grid Pass-Through mode. As PV comes up and DC becomes available, it will run in Grid Support mode. DC power will be inverted to supplement the loads up to 6kW. (In Grid Support mode the XW Pro can only invert 6kW, not the 6.8kW continuous and 12kW peak when running in Invert mode.) In Pass-Through or Grid Support modes the critical load panel can draw 12kW continuously, and in that scenario at least half is coming from the grid. All you need is a way to prevent the 5-ton AC unit from running when the grid is down, and all your other loads can be handled by the XW Pro in Inverter mode.....

Consider wiring your 5-ton central AC thermostat transformer to your main meter panel and feed it exclusively from the grid. When the grid drops your central air will too, and that load is prevented.

 

[superchachi]

FWIW, you may want to spray the inside of the container with closed cell foam while you are waiting for your batteries. We have a small window unit cooling our 20' container to 67 degrees constantly...it has no problem keeping up. My plan is to put a 9k or maybe 12k mini split in there at some point. We are in cental TX...it was silly hot this summer and that thing was a nice place to be. It would have made a fine man cave / workshop.