Conext Multi Unit new build - AC2 Charging

Hi there. New to the forum.

Trying to conect my EB10000 Honda generator for battery charging duty, and the 3x XW Pro I have refuse to use it to charge.

I have an external contactor. After increasing hz acceptable band I can now get it to AC pass through on my inverters reliably. However the inverters will NOT start charging.

I plan to be off grid but still have utility on site for construction. I disconnected generator and connected utility. With identical settings the XW Pro units began charging on utility with no issue.

When connected to generator, they qualify, and their screens stay blank '---' and show neither Watts or Amp indicator. AC pass through is indicated on my local insight home, both on utility when charging and on gen when not charging.

I read on the insight 1.18bn41 thread that @400bird had trouble charging from his XW on this FW. This is the FW I am on now. I will attempt using 1.17bn79 tomorrow and see if I can charge with the generator.

Any insight to this issue is welcome.

CMDRZOD said:

Hi there. New to the forum.

Trying to conect my EB10000 Honda generator for battery charging duty, and the 3x XW Pro I have refuse to use it to charge.

I have an external contactor. After increasing hz acceptable band I can now get it to AC pass through on my inverters reliably. However the inverters will NOT start charging.

Click to expand...

Do you have the generator connected to AC2? Supposedly it's got better acceptance of generator power.
Also, I'd just mess with one XW at a time. Concentrate on one inverter, just to simplify you settings.

Try increasing the voltage window, not just frequency. I've read reports here that an inductive load may help stabilize the generator and allow the XW to qualify it.

CMDRZOD said:

I plan to be off grid but still have utility on site for construction. I disconnected generator and connected utility. With identical settings the XW Pro units began charging on utility with no issue.

When connected to generator, they qualify, and their screens stay blank '---' and show neither Watts or Amp indicator. AC pass through is indicated on my local insight home, both on utility when charging and on gen when not charging.

I read on the insight 1.18bn41 thread that @400bird had trouble charging from his XW on this FW. This is the FW I am on now. I will attempt using 1.17bn79 tomorrow and see if I can charge with the generator.

Any insight to this issue is welcome.

Click to expand...

My issue with 1.18 was entirely operator error, doh! I have charge block timers set up and when updating to 1.18, it reset the internal clock. All I needed to do was fix the clock and it worked normally. Probably not applicable here.

Hi 400bird. Big fan of your contributions here.

Since I am using triple inverters with external contactor, only the master inverter is connected to AC2 which connects to the generator input before the contactor for sensing/synchronization.

The output (and input) is done on the AC1 terminal. AC out isn't used in this setup. The external contactor closes to link all inverters to the gen or utility input.

Google Conext multi unit setup and look at the section for 3 inverters + external contactor split phase, and you'll see how my system is configured. In this configuration only one AC input is possible.

I'm also using modbus for communication and control, but it's currently disabled to facilitate troubleshooting.

This is an image from the multi unit guide showing how I've connected my system.

CMDRZOD said:

Hi 400bird. Big fan of your contributions here.

Since I am using triple inverters with external contactor, only the master inverter is connected to AC2 which connects to the generator input before the contactor for sensing/synchronization.

The output (and input) is done on the AC1 terminal. AC out isn't used in this setup. The external contactor closes to link all inverters to the gen or utility input.

Google Conext multi unit setup and look at the section for 3 inverters + external contactor split phase, and you'll see how my system is configured. In this configuration only one AC input is possible.

Click to expand...

Ugh, I've seen it and forgot about it. That might complicate things, not sure.

Are you willing, as a test, to break of one inverter separate to see if you can get that generator qualified on a more basic set up?

Yes I have attempted to shut down the two slave inverters and used only the Master. It had no effect. AC pass through enables, but the charger will not start.

I have a significant distance from the generator, about 100 feet of #6 awg copper. Volt drop according to insight home is negligible, 245 no load to 237 at 4kw of house loads.

Going to shorten up cables tomorrow and give that a try but I doubt it is the issue.

I've read this generator has 10% total harmonic distortion, I'm wondering if that could be the issue.

CMDRZOD said:

Yes I have attempted to shut down the two slave inverters and used only the Master. It had no effect. AC pass through enables, but the charger will not start.

Click to expand...

Good start, did you hook the generator into AC2 on that inverter?

CMDRZOD said:

I have a significant distance from the generator, about 100 feet of #6 awg copper. Volt drop according to insight home is negligible, 245 no load to 237 at 4kw of house loads.

Going to shorten up cables tomorrow and give that a try but I doubt it is the issue

Click to expand...

I think you're right, probably not the cause, but still worth a try.

CMDRZOD said:

I've read this generator has 10% total harmonic distortion, I'm wondering if that could be the issue.

Click to expand...

I haven't seen a spec from Schneider, but that seems quite high. I think you may be on to something.

I spent yesterday troubleshooting my generator charge issue. Turns out it is volt drop related.


I shortened up my cabling to about 20ft of #10 cable, bypassing the 100ft of #6 I was using. Had to get the generator close to the house. No joy.

My fluke meter indicates a min voltage of 200-220v when the inverter chargers attempt to start. This triggers the F37. The generator does not leave AC Passthrough however. It remains connected and the external contactor remains closed, however charging will not start.

Not sure what else to try. My generator has a voltage regulator somewhere in its wiring, thinking of boosting to 250V no load and giving that a try.

I attempted downgrade to 1.11bn49. No effect. Same issue. Went back to 2.04. Will keep trying. Last resort is to pick up 7-8kw of 48v chargers and charge independently.

How old is the generator?
The Honda EB 10000 that i looked at had a digital voltage regulator. It advertised holding the voltage to 1%
Maybe your voltage regulatory is bad?
Also what is your charge rate on the XW inverter?

CMDRZOD said:

I have a significant distance from the generator, about 100 feet of #6 awg copper. Volt drop according to insight home is negligible, 245 no load to 237 at 4kw of house loads.

Click to expand...

CMDRZOD said:

I spent yesterday troubleshooting my generator charge issue. Turns out it is volt drop related.
View attachment 193798

I shortened up my cabling to about 20ft of #10 cable, bypassing the 100ft of #6 I was using. Had to get the generator close to the house. No joy.

My fluke meter indicates a min voltage of 200-220v when the inverter chargers attempt to start. This triggers the F37. The generator does not leave AC Passthrough however. It remains connected and the external contactor remains closed, however charging will not start.

Click to expand...

Sounds like you're already at 245 no load, I doubt that extra 5 volts will make a difference.
That's a pretty huge variability to the generator output voltage (200-245 vac)

CMDRZOD said:

Not sure what else to try. My generator has a voltage regulator somewhere in its wiring, thinking of boosting to 250V no load and giving that a try.

I attempted downgrade to 1.11bn49. No effect. Same issue. Went back to 2.04. Will keep trying. Last resort is to pick up 7-8kw of 48v chargers and charge independently.

Click to expand...

Yeah, it definitely sounds like the generator doesn't have the stability to support charging through the XW. (Or like CMDRZOD said, maybe something failed)

You could also try starting th charging current low and stepping it if the generator can support low charge levels.

I've been limiting the XW Pro chargers to 1kw each and less. Even with this wattage the inrush when the charger engages causes so much volt drop that F37 low voltage is triggered.

Yes I have the EB10000 Generator. It is good at holding voltage, I've load tested it to 8kw with loads, but sudden inrush like chargers combined with the spinning mass of the generator and engine result in a large enough lag time from current demanded -> current supplied that the XW Pro will see the supply as too unstable to attempt a charge.

Sounds like you're already at 245 no load, I doubt that extra 5 volts will make a difference.
That's a pretty huge variability to the generator output voltage (200-245 vac)

Click to expand...

My thought process here is that the XW and loads will easily work with 250V+, and if it can keep voltage just high enough during charger inrush to allow the charger to start, its a win.

I have also attempted to shutdown 2 out of 3 units and run a single charger from the generator. No joy. When I plug in grid power, chargers start without issue.

Also considering adding a large load to the generator, and disconnect it the moment before chargers engage to have the generator ramped during charger engagement which might be enough to offset the large current draw and prevent F37 from triggering. Its probably a bad idea to do this regularly but would be a fun test to try.

How old is the generator?
The Honda EB 10000 that i looked at had a digital voltage regulator. It advertised holding the voltage to 1%
Maybe your voltage regulatory is bad?
Also what is your charge rate on the XW inverter?

Click to expand...

Generator is brand new, brought home last week. It holds voltage well at high draw, the inrush of the charger transformer/ coils is the issue
Charge rate on XW for testing has been 1kw and below.

If your generator handles a 8k watt load it sounds like the voltage regulator is doing its job. I have 2 XW pro with a 10k watt diesel generator and the wrong charger settings will bring the generator to its knees.
Have you watched to Schneider electric xw pro troubleshooting video?
It touches on external Contactors and the BCS. Maybe it could help, I have attached it below

Hi @Mtnsun
Thank you for the video link. During dinner I watched it. When I got to the 38 minute mark he described my issue exactly and that the fix is in a pending firmware v2.10. I have already emailed my tech support rep asking to try this firmware.

Thank you for the link! I never would've thought it would address my issue directly. Once I can try that firmware I will report back here.

Just got off the phone with support. The tech told me the FW is not available for them to send. Just a bit frustrated to discover this issue in my offgrid setup that Schneider has known about for over 6 months, with the fix in development then and still not available to try.