question

tj-botten avatar image
tj-botten asked

Multiplus 2 Shuts down when changing from Absorption to float

Hi,

I have a Multiplus 2 with a 10.2kWh Revov battery set (2 x 200Ah 24.7V LiFePo batteries connected in series) and a Venus GX controller at a clients site. There is no battery management connected to the Venus.

The issue is that when the charging cycle switches from absorption to float the Multiplus switches off completely, then switches on to Inverter, switches off and on 3 times before finally switching on and continuing to run on float without any issues. The error on the Venus shows a grid loss error when this happens. The rest of the operations are fine.

I have run through the following:

  • Checked all terminations
  • Adjusted the Absorption and Float values
  • Checked both voltage and frequency at the incoming mains power
  • Checked the battery voltages and connections

Any suggestions here would be appreciated.

Multiplus-II
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

2 Answers
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @TJ Botten

without more information, its not possible to give any helpful answers.

can you describe the system further? ESS? what are the charging voltages, is the site on VRM? than you might be able to share AC / DC voltage graphs of what happens, etc. etc.


2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

tj-botten avatar image tj-botten commented ·

Hi Daniel,

The system is purely for backup power for when there is a mains failure so no ESS. There is a 240V input from mains and there is a backup load only that is below the rated power of the inverter.

The charging voltages are set as follows:

Abs-55.5

Float 54.4

Cut off 49.5

And I have set the charging current limit to 30A. Below is a screenshot of the graphs when the error occurs.

It is connected to the VRM console so we can arrange a time for you to take a look should you need to. I can mail you the csv output for this period should you need it.


Thanks


0 Likes 0 ·
jond avatar image jond tj-botten commented ·

@TJ Botten Hi, I have the exact same issue on a site. How did you solve this problem?

0 Likes 0 ·
tj-botten avatar image
tj-botten answered ·

Hi Daniel,

The system is purely for backup power for when there is a mains failure so no ESS. There is a 240V input from mains and there is a backup load only that is below the rated power of the inverter.

The charging voltages are set as follows:

Abs-55.5

Float 54.4

Cut off 49.5

And I have set the charging current limit to 30A. Below is a screenshot of the graphs when the error occurs.

It is connected to the VRM console so we can arrange a time for you to take a look should you need to. I can mail you the csv output for this period should you need it.


Thanks


1594020975126.png (67.3 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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