Looking for MP 170amp breaker for inverter to 24V LiFePO4 bank

[erik.calco]

I can find them on ebay rated up to 30VDC. But, I'm concerned that doesn't cover the high end of the voltage. I like the MPs, but am open to another maker if someone wants to recommend.

This is standalone, so needs its own housing. If someone can find a higher V rating with this quality for 170 amp, can they please link?

Also looking for good 300amp DC fuse I can fit 4/0 into with cover.

 

[Justin Laureltec]

Are you set on 170? I'm a fan of the Bussman 187 Series; rated to 48vDC nominal (so 56vmax actual), but unfortunately they jump from 150A to 200A, so whether one would work for you depends on your specified need for 170. They're not bad in price, though - a 200A is $59.50 and fully self-contained, weatherproof, and ignition protected.

For your 300A fuse, I'd suggest a BS-5133 Blue Sea (Bussman OEM) 300A ANL ignition-protected fuse in a BS-5005 fuseholder.

Full disclosure, those links go to my distributor website, but of course you can easily search the model numbers to source from any supplier of your choice.

 

[erik.calco]

I think this Samlex fuse helps me avoid the 4/0 requirement and saves me another battery cable. I'm running 4/0 in the bank, and 2/0 on the other side of the fuse. IIRC, @Steve_S likes these fuses.

I don't have marine or ignition requirements for the breaker since this is inside home. If I'm looking at $60+, I'm looking at a DC breaker box lol. But I absolutely want quality for this part. It's perty important.

 

[Justin Laureltec]

I think this Samlex fuse helps me avoid the 4/0 requirement and saves me another battery cable. I'm running 4/0 in the bank, and 2/0 on the other side of the fuse. IIRC, @Steve_S likes these fuses.

I don't have marine or ignition requirements for the breaker since this is inside home. If I'm looking at $60+, I'm looking at a DC breaker box lol. But I absolutely want quality for this part. It's perty important.

Ah, that works then... although since that's a 300A MRBF fuse and holder, I'll mention that we can beat that for you... Nuts I know I'm not supposed to advertise on these forums, it's just there's no reason for an MRBF holder and fuse kit to cost that much :-/

 

[Steve_S]

I do not have or use fuses. My system has DC Breakers on the DC side, AC Breakers on the AC side.
All by DC Breakers were supplied by Midnite Solar (via my E-Panel and subsequent upgrade purchases) The Breakers from MIdnite Solar are manufactured by Carling Technologies. They are "not" cheap by any means. https://www.carlingtech.com/hm-cb-f-series

When I ran with a 3KW inverter/charger, my main was 175A (Midnite part MNEDC-175), once upgraded to 4KW Inverter/Charger I upgraded the main breaker to 250A (Midnite part MNEDC-250).

 

[Justin Laureltec]

I do not have or use fuses. My system has DC Breakers on the DC side, AC Breakers on the AC side.
All by DC Breakers were supplied by Midnite Solar (via my E-Panel and subsequent upgrade purchases) The Breakers from MIdnite Solar are manufactured by Carling Technologies. They are "not" cheap by any means. https://www.carlingtech.com/hm-cb-f-series

When I ran with a 3KW inverter/charger, my main was 175A (Midnite part MNEDC-175), once upgraded to 4KW Inverter/Charger I upgraded the main breaker to 250A (Midnite part MNEDC-250).

Fully endorse the MidNite Solar breakers; the MNEPV series are the only ones we'll spec on the PV side of a solar controller because they're rated to 150vDC and series-connectable. Great little breakers and I have yet to find any manufacturer that can begin to compete.

 

[Steve_S]

Carling Technologies F-Series 175A 125VDC 1P Hydraulic-Magnetic Circuit Breaker (FA1-B0-14-917-12A-BG) for sale online | eBay

Find many great new & used options and get the best deals for Carling Technologies F-Series 175A 125VDC 1P Hydraulic-Magnetic Circuit Breaker (FA1-B0-14-917-12A-BG) at the best online prices at eBay! Free shipping for many products!

www.ebay.com

New Carling FA1-B2-16-825-11A-BG Circuit Breaker 250a 125vdc 1 Pole | eBay

Find many great new & used options and get the best deals for New Carling FA1-B2-16-825-11A-BG Circuit Breaker 250a 125vdc 1 Pole at the best online prices at eBay! Free shipping for many products!

www.ebay.com

That's about as cheap as you will find them.

 

[Bob142]

@Steve_S likes these fuses.

Nope. That was me. Amazon's got them a little cheaper here (unless you're avoiding Amazon).

 

[erik.calco]

Ah, that works then... although since that's a 300A MRBF fuse and holder, I'll mention that we can beat that for you... Nuts I know I'm not supposed to advertise on these forums, it's just there's no reason for an MRBF holder and fuse kit to cost that much :-/

Indeed you did beat it. Thank you. Is MRBF a form factor so that all the fuses work in all the holders, regardless of brand?

 

[erik.calco]

Carling Technologies F-Series 175A 125VDC 1P Hydraulic-Magnetic Circuit Breaker (FA1-B0-14-917-12A-BG) for sale online | eBay

Find many great new & used options and get the best deals for Carling Technologies F-Series 175A 125VDC 1P Hydraulic-Magnetic Circuit Breaker (FA1-B0-14-917-12A-BG) at the best online prices at eBay! Free shipping for many products!

www.ebay.com

New Carling FA1-B2-16-825-11A-BG Circuit Breaker 250a 125vdc 1 Pole | eBay

Find many great new & used options and get the best deals for New Carling FA1-B2-16-825-11A-BG Circuit Breaker 250a 125vdc 1 Pole at the best online prices at eBay! Free shipping for many products!

www.ebay.com

That's about as cheap as you will find them.

Lol Steve. Have you ever calculated a payback period?

 

[erik.calco]

Nope. That was me. Amazon's got them a little cheaper here (unless you're avoiding Amazon).

Not a Primed customer:



But, thanks!

 

[Justin Laureltec]

Indeed you did beat it. Thank you. Is MRBF a form factor so that all the fuses work in all the holders, regardless of brand?

Well, that's a good question. We only distribute Bussman fuses and holders (OEM for Blue Sea) MRBFs, so I can't actually confirm that any other manufacturer's fuses/holders would work - ie if a Bussman MRBF fuse would work in a different manufacturer's MRBF fuse holder. It should, and vice versa, but I can't independently confirm that.
It's worth noting, however, that Samlex's listings only have a picture of one side of the fuse and holder... and it's the side that doesn't have the actual manufacturer printing on it. I'd be willing to bet that if you ordered one and looked on the side that the picture doesn't show, it's gonna say "Bussman" on it.

 

[Bob142]

Not a Primed customer:

View attachment 2296

But, thanks!

Womp womp. Sorry.

 

[erik.calco]

@Bob142 you just pop this right on the M8 battery terminal? Saw a warning in one listing that it is not for "automotive" battery posts, but that doesn't apply to our LiFePO4 (non-explosive non-gaseous) ones with M8, right? I know it will fit. Just want to be sure there isn't a reason I haven't thought of why it's a bad idea.

The original goal was an inline like ANL within 7". But, the fuse world is just not friendly with 4/0.

 

[Justin Laureltec]

@Bob142 you just pop this right on the M8 battery terminal? Saw a warning in one listing that it is not for "automotive" battery posts, but I that doesn't apply to our lithium ones with M8, right? I know it will fit. Just want to be sure there isn't a reason I haven't thought of why it's a bad idea.

Hahaha for the record, I put that disclaimer on our listing for MRBF holders because people kept asking if they could drill out the holder's M8 hole to fit around their regular battery terminal (by which I mean, the clamping post) which, obviously, no. I got tired of answering the question so I added the disclaimer

Here's a pic of one installed on my test bench setup, showing how it attaches to a standard M8 (threaded insert in this case).

 

[erik.calco]

Hahaha for the record, I put that disclaimer on our listing for MRBF holders because people kept asking if they could drill out the holder's M8 hole to fit around their regular battery terminal (by which I mean, the clamping post) which, obviously, no. I got tired of answering the question so I added the disclaimer

Here's a pic of one installed on my test bench setup, showing how it attaches to a standard M8 (threaded insert in this case).

Awesome! This fuse eliminates the 6" 4/0 cable I was going to buy, which is about $12 with lugs.

After this fuse, it's all 2/0. But, I need to pick a breaker before I can figure those lengths out.

 

[erik.calco]

BTW, I am really loving draw.io with all its latest improvements. I've never been able to whip up a diagram this easily and quickly before.

 

[erik.calco]

@Justin Laureltec after looking at DC Breaker Box options, your $70 breaker is starting to look appealing. I'd kill if it was 170-175 amps.

Someone needs to do a video on putting together a DC distribution box. A shunt for negative bus? lol I can see why homes are primarily AC.

 

[LithiumSolar]

Also looking for good 300amp DC fuse I can fit 4/0 into with cover.

Have you considered these?
Class T Fuse Holder
Class T 300A Fuse

 

[erik.calco]

Thanks everyone. Ordered the breaker and fuse, and all the DC cables. Done with DC side. WHEW!!!