ET340 not connected and then connects (repeatedly) but only when PV production is high

Question

question

Huub asked Dec 20, '23

ET340 not connected and then connects (repeatedly) but only when PV production is high

ET340 connected to Multiplus II GX 5000 to control ESS. Battery 4 Pylontech US3000C batteries BMS active (Pylontech BMS on can bus)

AC connected to ACin only.

The system works correctly in ESS mode as long as PV input is low. As soon as PV production is in excess of ?2000W?, the ET340 drops repeatedly connection. So the ESS-system first reports 'external control' and is charging the batteries, then goes to passthru, (and reports discharge for 10 seconds, and then ET340 reconnects and the cycle repeats

In DVCC I limited charge current to 50A.

How to remedy the connection drop of the ET340 and get proper ESS control?

Thanks in advance

Energy Meter

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Jason - UK answered · Dec 23, 2023 at 12:53 PM

' an extension USB cable'

@Hu2bPV can you use the system without the extension cable? Extension cables create too much volt drop so the data transfer from RS485 to USB will become unstable. I would recommend using a powered USB hub but I like many others are yet to find one that works also without creating meter disconnects.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Jason - UK answered · Dec 23, 2023 at 12:56 PM

@Hu2bPV Im seeing 2 separate issues, Batteries stopping charge, im assuming from the battery BMS due to too high current, and a grid meter disconnecting due to the use of a USB extension cable. Try limiting the charger in the victron settings and see if that makes a difference.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Huub answered · Jan 13 at 08:33 AM

I apologize for any confusion.

I delayed posting this note in the hope of discovering a fault that wasn't a result of my own error. Unfortunately/fortunately, it appears that the issue originated from not fully removing the insulation around the ground cable. I stumbled upon this revelation while manipulating the ET340; touching it replicated the problem, prompting me to reevaluate the connection.

I've attached a graph depicting battery voltage and current. Despite a heavier load, the system consistently maintains its performance.

On a positive note, the USB3 hub has proven to work seamlessly, although its necessity remains uncertain. For now, I'll keep it as is.

I appreciate your collaboration and thoughtful consideration.

screenshot-2024-01-13-at-091948.png (173.8 KiB)

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2023-12-20T15:38:41Z

Huub answered · Dec 20, 2023 at 03:38 PM

Screenshot 2023-12-20 at 16.32.39.png Screenshot 2023-12-20 at 16.30.00.png

above graphs of the PV production and the erratic ESS behaviour .

Any ideas for ET340 disconnect? or is it interaction between BMS of the batteries and the ESS system? Or is there a problem with conversion of the analog data to a digital signal?

Thanks in advance for any suggestion how to proceed...

screenshot-2023-12-20-at-163239.png (317.7 KiB)

screenshot-2023-12-20-at-163000.png (188.4 KiB)

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Huub commented · Dec 23, 2023 at 12:36 PM

Some images above to illustrate the erratic behaviour of the ESS.

I hope to somebody can explain to me why I see large swings in battery charging power.

Is there something wrong with the ET340? Is the battery too cold (and is the Pylontech BMS interfering here ) or ??

Any comments well appreciated. Thanks

0 ·

screenshot-2023-12-23-at-125753.png (240.2 KiB)

screenshot-2023-12-23-at-125625.png (174.0 KiB)

screenshot-2023-12-23-at-125401.png (178.3 KiB)

screenshot-2023-12-23-at-125439.png (192.5 KiB)

Answer 2 · 2023-12-23T12:40:20Z

Jason - UK answered · Dec 23, 2023 at 12:40 PM

@Hu2bPV Regarding the ET340 disconnect, how is the ET340 connected to the GX device?

It might be prudent to take things back to basics just in case you have 2 different issues creating confuling situation. If you disconnect the PV and just use the batteries as an BESS, do you get any issues still?

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 3 · 2023-12-23T12:49:00Z

Huub answered · Dec 23, 2023 at 12:49 PM

Thanks Jason.

The ET340 is connected using a RS485 to USB interface with an extension USB cable.

The system works well for days as long as the PV input is not in excess of say 2000 W.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 4 · 2023-12-23T12:53:34Z

Huub answered · Dec 23, 2023 at 12:53 PM

The image illustrates that only with high PV input there are large swings in power input to the battery (on the 20th of December and again today)

screenshot-2023-12-23-at-135101.png (231.5 KiB)

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 5 · 2023-12-23T12:57:02Z

Huub answered · Dec 23, 2023 at 12:57 PM

Thanks for the suggestion Jason.

The distance between ET340 and victron is 8 m... I can use maybe some CAT6 cable to extend the RS485 to USB interface cable ? or use a powered USB hub yes....

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Jason - UK commented · Dec 23, 2023 at 12:59 PM

Ive tried 3 different USB powered hubs yet and I'm yet to find a stable powered USB hub. Each one I have bought has been a recommendation on this forum.

0 ·

Answer 6 · 2023-12-23T12:58:32Z

Huub answered · Dec 23, 2023 at 12:58 PM

I will limit charging to 40 A and see if that solves the problem. ...

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 7 · 2023-12-23T13:07:04Z

Huub answered · Dec 23, 2023 at 01:07 PM

clouds solved the problem for now.

I did set 40A charging limit in DVCC and limited charging power in ESS settings to 2000W.

thanks again for the suggestions Jason. (wait and see)

screenshot-2023-12-23-at-140354.png (209.8 KiB)

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Huub commented · Dec 24, 2023 at 10:28 AM

ok the gods of the clouds have an off day so a nice ramped up PV-production curve

What I see is that initially system is working nice : excess solar power stored in he batteries and grid put hovering around the set-point of 70W grid input

With increasing PV the representation of what is going on is intermittently disturbed:

incorrect but charging still ok

incorrect (grid and AC loads for L1 only presented; no total is given) charging still correct (around the set limit of 2000 W)

correct again

only L1 for Grid and AC loads

further degradation of representation what is going on

system trips : battery discharging now with 20W

this tripping repeats itself

I then turn on an electric heater (750W) on L1 and the system is behaving normally again:

I'm puzzled by the observations especially regarding the representation in VRM what the ET340 'reports' and how it misrepresents what is going on

Also it is puzzling to see that reducing excess power by turning on a heater on L1 is solving the tripping problem (effect of BMS?? but why?)

I hope you all find it interesting to see and I look forward to your comments. Thanks

0 ·

screenshot-2023-12-24-at-104621.png (171.7 KiB)

screenshot-2023-12-24-at-104805.png (199.6 KiB)

screenshot-2023-12-24-at-104819.png (196.6 KiB)

screenshot-2023-12-24-at-104909.png (196.1 KiB)

screenshot-2023-12-24-at-104926.png (179.9 KiB)

screenshot-2023-12-24-at-105040.png (177.1 KiB)

screenshot-2023-12-24-at-110046.png (198.6 KiB)

screenshot-2023-12-24-at-111858.png (217.6 KiB)

Answer 8 · 2023-12-24T11:55:21Z

Jason - UK answered · Dec 24, 2023 at 11:55 AM

@Hu2bPV do you have AES turned on in VE.Configure?

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 9 · 2023-12-24T12:28:34Z

Huub answered · Dec 24, 2023 at 12:28 PM

I'm not on the site so I cannot check. Please help me understand why this may be relevant.

in the meantime the battery is almost full. So the BMS had to limit charging power. and it graciously did: no more trips. Also the ET340 is behaving correctly. Excess power now feed into the grid.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 10 · 2024-01-04T08:09:21Z

Huub answered · Jan 04 at 08:09 AM

best wishes for 2024

just an update:

AES was not turned on

On returning home, there was and sun (PV 2000W) and the electric heater (3000W) was turned on and that led to a total disconnect of the ESS (connection to BMS Pylontech was lost). (in the control panel : ESS blocked)

Yesterday put a USB-3 hub (WLXKJY USB 3.0-Hub) with power supply (36 W)between the USB extension cable and the ET340 connection.

I also connected the AC Current sensor - single phase (CSE000100000) to measure PV production directly.

If it gets a bit sunny over the next few days, I can see if the system continues to behave even when larger loads occur both on the production and consumption side

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question