Multiplus II 48/5000/70 continually switches off with Error 1

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question

Roger Tschanz (brauchbares) asked Sep 24, '23

Multiplus II 48/5000/70 continually switches off with Error 1

System Description:

3-Phase ESS System with:

- 3x Multiplus II 230V 48/5000/70-50

- 2x SmartSolar RS, MPPT 450/200

- Cerbo GX

- 4x Pylontech US5000 (LiFePo: 4.8kWh each)

Prinzip Schema.pdf

Problem Description:

Since the first week I have installed the System, I face problems with the following error:

Alarm, #1 Device Switched off

This error appears on the console and causes the system to shut down and reboot after 1 minute.

It is important to know that:

- this error shows up independent of Time, Load, Temperature and Current

- there are no other errors shown on the console or anywhere else on the vrm datas or at the LED's on the Multis

- The error can show up (including shutdown of the whole house-electricity) once a week or 20 times a day!

Analysis done so far

I tried the following:

1. Switch Off the grid, and run the whole System independant (Isle-System)

--> same Problems

2. Switch grid back on, and switch off all Loads on AC Out of the Multis

--> same Problems

3. Switch off all Microinverters (Enphase IQ7-Series) and run Multis with Grid ON and with AC OUT connected normaly with our house

--> same Problems

4. I am working since 20 year on electronic-R&D and now I started to have closer look to the VE.Bus, because the more I try to find the bug, I think it could be a EMC Problem. So I tried to connect the Ethernetcable Shield to Earth (to Multiplus 2 housing)

--> same Problems

Now my questions:

1. Has anybody an idea what can initiate Error1 beside the reasons shown in:

VE.Bus Error Codes [Victron Energy]

2. Has anybody faced similar problems? How did you fix it.

3. How ist VE.Bus physically designed (I did not see any schematics, showing any EMC Elements)

4. RJ45 Sockets at Multiplus 2 are not shielded, I use shielded Ethernet Cables, do I have to connect the cables to the housing?

5. Why is it not recommended to use terminators? How can the bus run stable withot it?

I hope somebody has a clue how to get ahead and how to get rid off this errors...

error 1

prinzip-schema.pdf (218.5 KiB)

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Alexandra ♦ commented · Sep 24, 2023 at 10:10 AM

@Roger Tschanz

You will need to trouble shoot which device has the issue. You have three inverters, possibly one has a problem.

Have you checked them and made sure all connections internally are good. Not referring to your wiring only but also to inverter assembly.

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Roger Tschanz (brauchbares) Alexandra ♦ commented · Sep 30, 2023 at 02:24 PM

Thanks a lot for your response. At the moment I try to systematically check the wiring. I did also a new configuration of the Multiplus 2 Devices. I allways make one change per day, so I will hoppfully have an idea what causes the error(s). I will be a week in vacation, and will try to keep the forum up to date later on...

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Modifications Space

Node Red Space

Answer 1 · 2023-09-24T12:25:15Z

marekp answered · Sep 24, 2023 at 12:25 PM

@Roger Tschanz

I had a similar problem months ago.

Error#1 was happening sometimes 3-4 times a day.

My steps:

1. changed all RJ cables to Cat5.

2. keep the RJ cables away from AC cables and make them as short as possible.

3. identify which MP-II is switching off first and replace it with a new unit.

To identify the culprit I set up a video camera to see which one turns off its LED-s first.

After replacing this unit problem vanished.

https://community.victronenergy.com/questions/131578/1-device-swiched-off-repeating-problem.html

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Answer 2 · 2023-09-30T14:31:37Z

Roger Tschanz (brauchbares) answered · Sep 30, 2023 at 02:31 PM

Hi marekp, thanks for your hints.

I started with your step No 2, and it looks like there is an improvement. I will later on (after vacation) exchange all RJ Cables (Step 1) (They are Cat 5, but may be to old or not good quality). I will later on try to put a camera to identfy which one turns off first, but is this a hint that this unit is failing, or could it also be the wiring? I observed, that the fall time of the A and B signals of the VE.Bus are VERY slow, so I added now a terminator with 120Ohm, but this does not fix the problem, but it also looks like this is an imrpovement.

Maybe, there is more than one problem present....

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marekp commented · Sep 30, 2023 at 03:02 PM

@Roger Tschanz (brauchbares)

I never heard that terminator is required on the VE-bus network. I am not using it.

In my case i had a 6 unit 3-phase system. Two units per phase.

To identity the culprit I rolled back to single unit per phase.

After month of testing I noticed that phase 3 is turning off first causing error#1.

After switching to other unit on phase 3 and waiting 3 months for the fault and not getting it, I decided that the other unit is faulty and replaced it.

Of course all this testing was done after going through point 1 and 2 of my list things to do.

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Answer 3 · 2023-09-30T14:56:50Z

nickdb answered · Sep 30, 2023 at 02:56 PM

Does the gx, under notifications, not provide a device number? It does for errors in parallel systems, relay failures anyway, which you can look up from the inverter device details on the gx and translate into a serial number.

This isn’t shown on VRM.

Might only apply to error 11/18 but worth a look.

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Answer 4 · 2023-11-01T14:29:44Z

Problem solved

Dear Victron-Friends

First of all, thank you for your support. In the meantime I realized several of your proposed steps. And the system is now working without any problems.

Here the solution to the initial problem:

All communication cables are Cat. 5 (shielded)
All Communication Cables (VE.Bus, VE.Can, BMS.Can, Temp. Cables) are now strictly kept away from DC and AC wiring. At least 20cm apart, and if crossing of a DC or AC wire is required, the crossing is made rectangular. No parallel wiring.
For all VE.Bus Communication Cables I connected the RJ45 Connector to PE (Ground) at one point (connect only one end to ground and keep the other connector housing floating)

For my 3-phase system that means:
- at L1 (master phase) one communication cable goes to L2. Cable housing(shield) is
grounded at L1 and the other communication cable goes to L3. Cable housing (shield) is
also grounded at L1
(Star topology)

- at L2 I added an other communication cable that is connected to Cerbo GX. The cable's
housing (shield) is grounded at the cerbo.

Very Important: cabeling has to be done with all systems turned off and Battery switched off, else it can be very dangerous (shortcuts with the DC or AC system).

4. Terminator Resistor is not needed for my setting, but signal fall time is very long without a
terminator. It is not clear for me, why Victron does not use any terminator resistors. If using long
communication cables this could become a problem.

5. I used a Node-Red algorithm to manage battery SOC (state of charge). This algorithm occupied the VE.Bus once a second to tell the Multiplus what amount of energy has to be fed into the
grid. (grid Feed in parameter). After turning off this algorithm the system worked a lot more
stable. (But still some Device-switch-offs per week)
This additional bus traffic could have leaded to communication collision (if regular protocoll
packages are collided, the system turns off). "regular protocoll packages" are used to
synchronize the three phases.
Another problem of my algorithm could have been, that may be the regular ESS Assistant
became unstable, because of the additional demands of grid-feed-in. My commands fighted
against the ESS Assistant commands...

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