Misleading Error message

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GRIGORIU asked Apr 26, '24

Misleading Error message

I just installed my Multi RS Solar. Works fine now but I have encountered a small issues that took me 15 minand that could have been prevented by a more clear message.

Hardare: A multi RS Solar + a Cerbo GX + a Pylontech US5000

Description:

About 30 after installation the unit showed Err 67 - BMS Connection lost

So I checked the cable between the BMS and the Cerbo ( all ok three times !! )

The issue was in fact the cable between the Multi RS and the Cerbo !

It would have been usefull to have a separate error connection lost with Cerbo and Connection lost between cerbo and BMS.

OR if not possible at least put a more clear description of the possible points of failure in the description of the error codes in the manual;I know it is stupid and simple but that saves a lot of time.

error Multi RS

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Answer 1 · 2024-04-26T17:31:01Z

Matthias Lange - DE answered · Apr 26 at 05:31 PM

I'm pretty sure that the massage was something like:

Multi RS: error 67 BMS connection lost

You can look at the alarm log on the VRM Portal.

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Answer 2 · 2024-04-26T17:59:34Z

snoobler answered · Apr 26 at 05:59 PM

@GRIGORIU It's a matter of following logical troubleshooting procedures.

When a BMS is present, charging devices are under "external control." If this external control signal is lost, you get error 67. This means that there is a fault SOMEWHERE between the BMS and the device in question. The only thing the charger knows is, "the BMS is no longer present." It doesn't and can't know why, but YOU can gather additional data in less than 30 seconds to determine where the fault might be.

Troubleshooting would have you start at the BMS. If you had seen the BMS connection working in the Cerbo and/or VRM is properly showing BMS data, then you would then move outwards from the Cerbo to the RS, which would then lead you to suspect the connection between the Cerbo and RS.

Example of symptoms of a simple MPPT with two different fault causes:

1) MPPT VE.Direct or VE.CAN cable removed from Cerbo:

Error 67 reported. No other symptoms/errors.

2) BMS disconnected from Cerbo:

Error 67 reported.
Cerbo and VRM report no BMS data
Cerbo shows nothing connected to BMS-CAN

Error 67 coupled with other simple checks readily pinpoint the most likely point of failure. It is not misleading.

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GRIGORIU commented · Apr 26 at 08:34 PM

I completely agree. That is what i done but it takes a few minutes. The issue that all cable were home made because it had to fit the distance.

When impertfect connections arrise the fault can be intermitent (as it was here).

Also, personally I do not stare at the Multi all the time to see that the connection is lost. I am waiting tpo the fault to be reported.

However I do not agree that the Multi cannot know where the fault is.

The Multi can easily see that the link with the Cerbo is broken or not and to see if the CErbo is reporting something and report some #67A or #67B error.

It is just a suggestion but I tend to give newbie-proof messages.

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Answer 3 · 2024-04-26T20:07:49Z

Alex Pescaru answered · Apr 26 at 08:07 PM

Hi @GRIGORIU

Error #67 is indeed indicating a BMS comm loss, but until then, the unit already had shown a loss of Cerbo communication for a long time, by NOT showing the communication icon.

Paying attention to little things... :-)))

Alex

comm.jpg (20.7 KiB)

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