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Multiplus II -- 48/3000/35-50 (120v) Not Honoring AC Input Limit and Showing Input Current as Negative on AC OUT 1

Hi -- the title has most of the relevant details. Any help would be greatly appreciated! I'm starting to think I have a faulty unit and am not sure what else to change in the settings.

Details:

  • Multiplus II -- 48/3000/35-50 (120v) -- just hooked up in the past two weeks, purchased in March.
  • Firmware 2729496.vff
  • Tested AC Input for the first time today.
  • AC Input Current Limit set to 10 amps (minimum per the minimum shore current limits.xlsx document should be 9.5 amps w/ power assist enabled)
  • Power assist factor, 2.0
  • Charging current limit, 25 amps (this seems to also not honor the AC input current limit)
  • VE Bus w/ Cerbo GX for monitoring

Problem:

There are two problems, maybe related:

  • The multiplus II does not honor the input current limit -- If I am connected to shore power, and apply more loads than 10 amps, instead of the multiplus assisting to meet the load, it draws from the AC input, greater than 15 amps (1800w-ish), and blows the input breaker.
  • The multiplus II knows when AC input (shore power) is connected and displays this in the UI, but shows 0w and 0.0 Amps being drawn. It shows the charging current to the batteries as a negative load on AC OUT 1, rather than on AC IN 1.

I've attached screenshots illustrating this situation.

Things I've Tried:

I've tried restoring to a fresh firmware file and default settings, still with no luck and the same results. I've also double checked wiring with a multimeter to make sure nothing is criss-crossed.

I tried rolling back to firmware version 2729492.vff (v 492 vs v496 which is latest). This also had no affect.

I've also tried disabling power-assist, with no success. The same problems still persist.

I don't see anything in the firmware change-log which would indicate this functionality has had any changes since multiplus-II support was added.

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Multiplus-IIac
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2 Answers
yld avatar image
yld answered ·

Update -- I spent probably 5 hours flashing firmwares, changing settings, checking wires.

The fix was the "headphone trick" -- stick a 3.5mm headphone cord into the "AC Input Sensor" jack on the multiplus a few times and it fixes whatever short might be happening in there.

Everything works as expected after -- wild.

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bruno-o avatar image
bruno-o answered ·

Great, I had the same problem with a MultiPlus II 5k, the 3.5 headphone trick did it for me too!

Many thanks.

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Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

MultiPlus-II 230V Datasheet 

VE.Bus Error codes

Additional resources still need to be added for this topic