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basti avatar image
basti asked

Pre-Charge inverter - Are there potential issues with other DC side equippment during pre-charge?

Hello folks.

Am Currently building a system, and am wondering about the pre-charge-issue.

I have a BMS (SimpBMS), which will (after checking battery parameters) trigger a pre-charge contactor before triggering the main contactor. So far so good. I however wonder, how to pre-charge the inverter, while I have other items connected to the DC side of the battery (see drawing below).

Manually disconnecting all breakers/fuses for the 48V DC equipment other than the inverter, before system-(re)start is nothing I'm looking forward to. A second contactor (as in the drawing) might be an option, but also means additional and ongoing power usage (for my island system), therefor not ideal.

Can anybody clarify the issue, after looking at my over-simplified drawing (am lacking a schematics program)?


Thank you.pre-charge-over-simplified.png

wiring
pre-charge-over-simplified.png (126.1 KiB)
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1 Answer
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @Basti

Depending on how the system will be run, normally the contactor never has to open.

Also, depending on the system, pre-charge you'll have to do pretty fast, so a low resistance resistor, because users might start up and start pulling power.

So it's something you'll have to experiment with a bit to get right.

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