Circuit breaker fail.

[hugemoth]

I shut off this breaker to do some work to the system and it wouldn't complete the circuit when turned back on. The breaker was on the positive cable for a 1000 Watt inverter. No smoke or heat detected and the breaker has never clicked off on its own. I put a fuse in its place for the time being.

 

[mikefitz]

and it wouldn't complete the circuit

Poor quality low cost breaker, replace with Bussmann/Blue sea,
Example,

Blue Sea Systems 7149 187-Series Circuit Breaker, Surface Mount, 200A | eBay

Find many great new & used options and get the best deals for Blue Sea Systems 7149 187-Series Circuit Breaker, Surface Mount, 200A at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[hugemoth]

For $72 I'll use a fuse. The one that failed cost under $12 shipped.

 

[Q-Dog]

For $72 I'll use a fuse. The one that failed cost under $12 shipped.

They are cheap for a reason. Good breakers cost money.

 

[wpns]

The one that failed cost under $12

#FalseEconomy. So, tear it apart and tell us the results of your failure analysis!

 

[Kornbread]

If you absolutely have to have something 12v and cheap. Used these on lead acid battery banks, although, I'm not sure I'd trust them with a large LiFePo4.

 

[hugemoth]

I drilled out the rivits and opened it up. It's basically a bimetallic plate and contact points like an old car. The contacts are not pitted and there is no sign of overheating. My best guess is the little plastic lever inside that opens the contact points was twisted out of place and partially broken which wouldn't allow it to move enough to release the contacts, although I may have damaged it during disassembly.

 

[Brucey]

If you absolutely have to have something 12v and cheap. Used these on lead acid battery banks, although, I'm not sure I'd trust them with a large LiFePo4.


View attachment 209100

Someone here did a test of them while connected to a bunch of Victron LFP batteries, it did end up ejecting a bunch of sparks and molten metal from the fuse so definitely not good for a gas boat. But still better than a cheap piece of crap that doesn't do anything or catches on fire just sitting there working.

 

[pollenface]

Oh yeah!

Exactly the type of breaker the rest of the internet says DO NOT USE

They work well as isolators though, I have a bunch of them. Just don't use them as breakers per se

 

[wpns]

I drilled out the rivits and opened it up. It's basically a bimetallic plate and contact points like an old car. The contacts are not pitted and there is no sign of overheating. My best guess is the little plastic lever inside that opens the contact points was twisted out of place and partially broken which wouldn't allow it to move enough to release the contacts, although I may have damaged it during disassembly.

So it opened when you pressed the button, but wouldn't close again, and probably a purely mechanical problem? I guess that's a better failure mode than not tripping on overcurrent or not opening when you press the button.

 

[OzSolar]

Another member is selling some nice breakers at a really good price. You’ll have to get creative with an enclosure.

Thread 'Ironridge Conduit Mounts & 100 amp DC Breakers for sale'
https://diysolarforum.com/threads/ironridge-conduit-mounts-100-amp-dc-breakers-for-sale.81864/

 

[hugemoth]

Yes the failure would not have prevented the circuit breaker from opening in an over current situation, it just prevented it from closing the circuit once I manually opened it.

 

[Kornbread]

Someone here did a test of them while connected to a bunch of Victron LFP batteries, it did end up ejecting a bunch of sparks and molten metal from the fuse so definitely not good for a gas boat. But still better than a cheap piece of crap that doesn't do anything or catches on fire just sitting there working.

Dang. That's not good. So far nothing like that has occurred with pop's system, and we've popped a few of those mrbf fuses. Looking at the fuses, it was hard to even tell they were done.

 

[robbob2112]

Before pooping on the MRBF read the thread. The current used was a massive hit far in excess of what you would expect in a normal install. And it did interupt the current and extinguish the arc. There was a large flash and the plastic shattered from it. Interesting thread.

If a spark is a concern use a class T.

 

[Brucey]

Dang. That's not good. So far nothing like that has occurred with pop's system, and we've popped a few of those mrbf fuses. Looking at the fuses, it was hard to even tell they were done.

It's very unlikely your pops system had anywhere near the amps involved in that test.

 

[Kornbread]

It's very unlikely your pops system had anywhere near the amps involved in that test.

Yeah, that's what I'm thinking. Ok, for a cheap alternative better than many other options for a small 12v lead-acid system, but IMO, it's a hard no with a larg'ish LiFePo4 bank. FWIW, all the fuses in the home system are class-T. For the first time ever, I'll be adding a dc mccb to the 48v inputs of the new nhx inverters. The breakers are more for on/off convenience than anything as those circuits are also covered by class-T fuses.

 

[JRH]

I shut off this breaker to do some work to the system and it wouldn't complete the circuit when turned back on. The breaker was on the positive cable for a 1000 Watt inverter. No smoke or heat detected and the breaker has never clicked off on its own. I put a fuse in its place for the time being.
View attachment 209095

Knock off..knock off…knock off.. get the real deal …

 

[Brucey]

Yeah, that's what I'm thinking. Ok, for a cheap alternative better than many other options for a small 12v lead-acid system, but IMO, it's a hard no with a larg'ish LiFePo4 bank. FWIW, all the fuses in the home system are class-T. For the first time ever, I'll be adding a dc mccb to the 48v inputs of the new nhx inverters. The breakers are more for on/off convenience than anything as those circuits are also covered by class-T fuses.

Not sure what sizing you are going for but the 250A midnite breakers are on sale at altE store for $47+shipping, if you get two or more shipping isn't too bad:

Midnite 250A 125V DC panel mount breakers for $47 at altE

I hesitate to share this one as I'm sure all 43 remaining units will be snapped up fairly quickly. Normally retail for around $90-100, altE was already the cheapest prior to this mega drop. I ordered what I could afford wish I could get them all lol. Rated for 50,000 AIC at 125V. Seems cheaper...

diysolarforum.com

 

[Kornbread]

Not sure what sizing you are going for but the 250A midnite breakers are on sale at altE store for $47+shipping, if you get two or more shipping isn't too bad:

Midnite 250A 125V DC panel mount breakers for $47 at altE

I hesitate to share this one as I'm sure all 43 remaining units will be snapped up fairly quickly. Normally retail for around $90-100, altE was already the cheapest prior to this mega drop. I ordered what I could afford wish I could get them all lol. Rated for 50,000 AIC at 125V. Seems cheaper...

diysolarforum.com

Now you tell me, and I already have some enclosures that would work to front mount those breakers.

 

[Brucey]

Now you tell me, and I already have some enclosures that would work to front mount those breakers.

What enclosures are those? Ideally I could buy midnite DC disconnect boxes without the breakers for cheap but very rare to find them like that.