Circuit breaker between inverter and battery question.

[Danke]

Sol-Ark had internal breakers on the battery terminals for just the positive. I have inverters without internal breakers. So looking to add external breakers. (I already have T Class fuses that I will also be using)

I was speaking with a manufacture of batteries, and they sent me this suggested external breaker and diagram. Thoughts?

 

[SeaGal]

Thoughts?

Only thought is "Have you still not chosen one?"

Is this a DC Circuit Breaker?

A 125A breaker of the same family is used on my EG4 LLv2 48V (UL) battery.

diysolarforum.com

Single vs. Multiple Class-T Fuses

@cods4 There isn't anything concrete, and installed fault current is apt to be highly dependent on local installation conditions. The cells themselves have a calculated dead short fault current on the order of 20kA. More cells in series does not, in and of itself, change this, as each time you...

diysolarforum.com

Seriously though, this one clearly shows DC performance and has that magnetic wotsit in it, which I understand is a good thing, so why not?

 

[DIYrich]

I have Class T fuse on the wires, and use the BMS to turn a battery on/off and limit draw. the only downside to not having a breaker or switch is that I have to turn off all the batteries to physically disconnect a battery. Not a big deal for that one minute since I rarely have to do it.

It does require a Class T on each battery wire (or wire from rack to busbar), rather than one Class T from the busbar to the Inverter. My wires from the batteries to busbar are smaller than the wire from the busbar to the inverter. So I put smaller Class T on the battery wires that connect to the busbar. I'm banking on the Inverter's breaker to protect the inverter wire. I figure if one class T blows because of a short at the busbar or after, that they will all blow. If all the Class T's are maxing out without blowing, then hopefully the inverter's breaker can handle it.

 

[Shimmy]

Single pole is code compliant for 48V in the US. It is best to follow what the inverter manufacturer recommends though; some designs need both poles isolated for safety, some add safety with two poles (GFI), but some may not like both poles being isolated while the unit is running.