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48v Battery Bank Disconnect

dbrfan

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Joined
Mar 17, 2021
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I know this has been answered somewhere, but I haven't found it yet, so please bear with me.

I'm building a 16S 48V 160ah (standard .5C) battery bank with a Victron 3kw/120v inverter/charger. No solar at this time, just a power wall. The Winston Sky battery cells have a max rating of 4V, so in theory could reach 64V.

Peak inverter demand at 6kw is 125A, so 25% over that is 156A. I'm going with a 150A ABB shunt between a Blue Seas power distribution bar and the inverter/charger. I am planning for a 150A class T fuse between battery and the distribution bar.

I wanted to add an isolation/disconnection switch between the class T fuse and distribution bar on the positive cable, but am having a hard time finding a switch. The Blue Seas manual battery switches (m, e, hd series) all have an absolute 48V limit, so they don't appear to work for my system. I've found DC circuit breakers in the thousands of dollars, but those don't work for the budget. I suppose that I can go the route of another ABB Sace3 or Sace5, eliminate the class T and just use the ABB as a dummy breaker, no shunt. Any advice from the experts on this forum?
 
We're still trying to figure out the reason for a hard 48V limit on those switches.
Opening under load, there would be an arc problem. Closed carrying current and open not carrying current, no apparent electrical issue.
As far as we can tell it is for human safety, keeping people from touching higher voltage circuits.
Further tests and maybe other design considerations would be required for certification if rated for higher voltages.
 
There are some moderately priced breakers with current and voltage ratings that meet your needs.


Midnight has products they obtained from another manufacturer, but put them through certification testing. Same physical part can be purchased from OEM but doesn't come with same NRTL rating.
 
There are some moderately priced breakers with current and voltage ratings that meet your needs.


Midnight has products they obtained from another manufacturer, but put them through certification testing. Same physical part can be purchased from OEM but doesn't come with same NRTL rating.
This is great, thanks so much!
 
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