DIN Rail DC Breaker for 48V LifePO4 battery

[Henderson]

Does anyone know of any 2 pole DIN rail non polarized DC breaker capable of handling say 200/250A? If such a breaker/switch exists, looking to use it as a main switch for a 48V lifepo4 battery. Would appreciate this forum's thoughts/recommendations. Thanks in advance.

 

[FilterGuy]

Same answer as your other post:

I used to want breakers everywhere, but have come around to using fuses for anything needing 150A and above. If a 150A safety device pops, it is a big event that means something catastrophic happened. If a circuit is designed that can occasionally pop a 150A breaker.... the circuit needs to be redesigned.

 

[Shimmy]

I used to want breakers everywhere...

I want breakers instead of switches because I know they are designed as load-break devices. Most of the switches are a little sketchy in this area.

 

[Henderson]

Thanks for the comments thus far. I should've mentioned that I do intend to use T Class fuses for the batteries as my main circuit protection. I do however need a switch and like the practicality of the DIN rail setup. The DIN rail breaker would act as my main battery switch and because it's a breaker, will also add some redundant protection but it's primary use will be as a switch. I guess I can use a 125A 2 pole breaker and run +ve polarity through both poles to get the 250A but I like the idea of a main switch being able to disconnect both +ve and -ve terminals. Now a 4 pole DIN rail breaker would be sweet but haven't been able to find any of those in 125A sizes. I'm building 2x 3p16s batteries using 280ah lifepo4 3.2v cells. Each battery by itself must be able run the load for the entire house and charge the EV in the event that one of the batteries need to be offline for some reason.

 

[Brettw]

Thanks for the comments thus far. I should've mentioned that I do intend to use T Class fuses for the batteries as my main circuit protection. I do however need a switch and like the practicality of the DIN rail setup. The DIN rail breaker would act as my main battery switch and because it's a breaker, will also add some redundant protection but it's primary use will be as a switch. I guess I can use a 125A 2 pole breaker and run +ve polarity through both poles to get the 250A but I like the idea of a main switch being able to disconnect both +ve and -ve terminals. Now a 4 pole DIN rail breaker would be sweet but haven't been able to find any of those in 125A sizes. I'm building 2x 3p16s batteries using 280ah lifepo4 3.2v cells. Each battery by itself must be able run the load for the entire house and charge the EV in the event that one of the batteries need to be offline for some reason.

I know this answer is late, but if you go to the parts on Will's 48v off grid schematic in the menu tab (top left corner of this page), he has a link to a 200 amp dc breaker that will do what you want. It's from signature solar, you can just take out the copper busbar they are using to make it a mono pole. Not sure why you want to disconnect both the + and the - side though? Just the + side would be sufficient unless you live in a country where both sides are required.

 

[timselectric]

I use two pole breakers for everything DC in my system. Positive and negative are both ungrounded conductors. And NEC requires that all ungrounded conductors be disconnected simultaneously. And both require over current protection.

 

[Brettw]

I use two pole breakers for everything DC in my system. Positive and negative are both ungrounded conductors. And NEC requires that all ungrounded conductors be disconnected simultaneously. And both require over current protection.

I'm pretty sure you answered a different question I had about fusing or using a breaker on the positive or negative side of the battery bank, you told me the positive side needs to have the breaker. No mention of the negative cable in your previous answer. I'm just a newbie trying to figure it all out, but you just added something new to me.

 

[timselectric]

I'm pretty sure you answered a different question I had about fusing or using a breaker on the positive or negative side of the battery bank, you told me the positive side needs to have the breaker. No mention of the negative cable in your previous answer. I'm just a newbie trying to figure it all out, but you just added something new to me.

If you were to only protect one, the positive is the preferred.