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simon-gent asked

Is the Lynx Smart BMS 1000 not able to rush in a three-phase system of 3x15kVA Quattro's?

Hi all,

I get the Pre-charge error E-B25: The load resistance is too low to precharge the loads. Disconnect or reduce some DC loads.

My system is the following:

- 4 Victron Smart LFP batteries 200 25,6/200-a
2 parallel strings with two batteries in series

- Lynx Smart BMS 1000A

- 3 Quattro's

I see from the figure below that the precharge resistor is 47Ohm. At the moment of precharging the battery voltage is 53.5V. That makes 1.14A and 61W power dissipation at the inrush resistor. When I searched for this resistor on the internet I found that max power dissipation is 75W.

Does Victron measure inrush current and limits it? Is there perhaps a temperature measurement that trips? Does anyone know what these limits might be? It might be 1A?


Many thanks,
Simon



1719056658222.jpeg

MultiPlus Quattro Inverter Chargerlynx bmsin rush current
1719056658222.jpeg (3.4 MiB)
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@Simon_Gent Resistor 4R7 is 4.7 ohm.
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2 Answers
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Duivert NL answered ·

arent your batterys to small?? as far as i know minimum is 20kW per quattro 15k, so 60kW in your case

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simon-gent answered ·

I will use them at the final location with 12 batteries, 60kWh. Now I just wanted to start the system.

I have discoverd I reversed polarity of one Quattro. I made my own precharger using a lab DC source and I was pumping 5A at low voltage into the DC rail for like 10 minutes. I saw that the full 5A went to the reversed connected Quattro. Will this result in permanent damage?

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It can, but normally it occurs catastrophically from high current supply.


There is no DC reverse polarity protection for the Quattro.


Given in this case it was done with low current from your pre-charge circuit, if they unit is now working (once you corrected the polarity), then it might be ok.

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