Is This Breaker Really Non-Polarized?

[Henderson]

Hi all, I'm looking at the Taixi TXCM1B series breakers and the folks at AliExpress tells me it's non-polarized. I know some on this forum are not AliExpress fans and that's ok, but can I get an objective opinion on the Taixi TXCM1B series of breakers? I'm looking to use this breaker as my main DC disconnect for my battery bank. So this will isolate my battery bank from my inverters (2x EG4 6500EX 48V). I will be using BlueSea T class fuses as well for the battery bank (2x 2P16S Lifepo4) but want the additional functionality of being able to isolate the batteries from the inverters, and if I can have the isolation switch also provide over current protection, then that's ideal.

I also saw these Taixi breakers listed on Andy's site where he says it's quite good as a main battery disconnect. Perhaps I may be confused but my understanding is that for battery breakers, they should be non-polarized so they offer protection for both charging and discharging. The Taixi TXCM1B breakers have + and - symbols and also shows how which terminals the load should be connected to. Despite that, AliExpress is saying that they are non-polarized so I am reaching out to this forum to confirm based on the markings on the breaker, are they indeed non-polarized?

So I'm hoping that more knowledgeable persons than me on this forum can clear up this matter for me. Is this breaker non-polarized and will it protect for over current for both charging and discharging? I have the 600A double pole version. I've also attached the documentation which the folks at the Taixi store from aliexpress sent but I'm not seeing anything that says if its polarized or non-polarized. A note on the Taixi store folks....they're very responsive but I just want to make sure what I am being told is accurate before I place this critical breaker on my system. Ideally I would've loved to use the NoArk breakers that Andy uses but the store in Australia seems to not ship internationally.

Another question...is directional/non-directional, the same as polarized/non-polarized? Does directional mean polarized and non-directional mean non-polarized?

Thanks as always to folks on this forum for your guidance.

 

[timselectric]

Another question...is directional/non-directional, the same as polarized/non-polarized? Does directional mean polarized and non-directional mean non-polarized?

Yes

 

[Mattb4]

...

Another question...is directional/non-directional, the same as polarized/non-polarized? Does directional mean polarized and non-directional mean non-polarized?

...

Not to me it doesn't. Bi-directional DC breaker would mean that it can interrupt current no matter which direction it flows from. Polarized simply means positive in - positive out, negative in - negative out The reason for the + and negative on the Bkr terminals is for magnetic arc quench.

However I am aware that many use polarized to mean directional in DC breakers. I disagree with this nomenclature as being confusing and state the breaker is directional with a supply side and load side.

 

[timselectric]

A polarized breaker is identified for the "direction" of current flow.

 

[Henderson]

Ok thanks for the input. Any feedback on the breaker itself? Is this a polarized/directional breaker?

 

[Mattb4]

Looks to my eye like a directional breaker. Load into top and supply out the bottom. I see a wiring diagram on the breaker face with lug one as pos and lug 2 as neg indicated. That would indicate that it is polarized for which lead is connected to which lug.

 

[Henderson]

Looks to my eye like a directional breaker. Load into top and supply out the bottom. I see a wiring diagram on the breaker face with lug one as pos and lug 2 as neg indicated. That would indicate that it is polarized for which lead is connected to which lug.

Ok thanks. I was kinda thinking the same as well but wanted to make sure. The folks at Ali said that the diagram on the breaker is only for illustrative purposes but could be connected either direction which made my spidey senses tingle a bit. I see that Andy recommends these breakers on his website but after some thought I then remembered that Andy doesn't have AOI inverters so these types of breakers can definitely work for his particular scenario.

 

[Mattb4]

There is a interested read about what it takes to design a bidirectional DC breaker here: https://www.researchgate.net/public...cessary_bidirectional_interruption_capability

 

[Mattb4]

Ok thanks. I was kinda thinking the same as well but wanted to make sure. The folks at Ali said that the diagram on the breaker is only for illustrative purposes but could be connected either direction which made my spidey senses tingle a bit. I see that Andy recommends these breakers on his website but after some thought I then remembered that Andy doesn't have AOI inverters so these types of breakers can definitely work for his particular scenario.

The SCC that have separate wires going to charge a battery and battery wires going to inverter could use this type of breaker.

 

[Henderson]

Thanks.

 

[timselectric]

I defer to Matt's evaluation of the chosen breaker.
I don't download files on my tablet.

 

[Mattb4]

Incidentally for my own usage I use a directional breaker inline with fuses for the AIO I have. The fuses provide circuit protection and the breaker acts as switch for disconnection when not under load.

 

[timselectric]

Incidentally for my own usage I use a directional breaker inline with fuses for the AIO I have. The fuses provide circuit protection and the breaker acts as switch for disconnection when not under load.

I'm actually thinking about switching to a polarized breaker for cost savings. As I need a total of 22 of them.

 

[Henderson]

Sounds like the Taixi breaker then could be useful after all? Especially considering that I will also be using t class fuses?

 

[Ron-ski]

I suggest you look at the Z Beny breakers, they are advertised on their website as no polarity, both the large moulded case breakers and the small MCB breakers, and they were cheaper than the Taixi ones I bought, only catch is you have to make an enquiry through their Alibaba store, but I've ordered twice and all went smoothly on both occasions.

See this post here as well https://diysolarforum.com/threads/s...ectional-battery-protection.49824/post-656399

 

[Henderson]

I suggest you look at the Z Beny breakers, they are advertised on their website as no polarity, both the large moulded case breakers and the small MCB breakers, and they were cheaper than the Taixi ones I bought, only catch is you have to make an enquiry through their Alibaba store, but I've ordered twice and all went smoothly on both occasions.

See this post here as well https://diysolarforum.com/threads/s...ectional-battery-protection.49824/post-656399

Thanks for your suggestion. Much appreciated.

 

[RotEvery]

Not to me it doesn't. Bi-directional DC breaker would mean that it can interrupt current no matter which direction it flows from. Polarized simply means positive in - positive out, negative in - negative out The reason for the + and negative on the Bkr terminals is for magnetic arc quench.

However I am aware that many use polarized to mean directional in DC breakers. I disagree with this nomenclature as being confusing and state the breaker is directional with a supply side and load side.

Here are my thoughts on this. These 2-pole DC breakers are all directional whether uni-directional or bi-directional. As long they are polarized, they are directional. There's some relationship (however slight) between being directional and being polarized. Seems confusing but it's true.

For bi-directional DC breaker, for the following connections, the breaker positive and negative terminals are swapped:
1. When you choose top-to-bottom flow direction (power source connected to top terminals).

VERSUS

2. When you choose bottom-to-top flow direction (power source connected to bottom terminals).

In both cases, the polarity specified (on the breaker or in the manufacturer documentation) for the particular flow direction chosen by you (the installer or user) must be complied with.

I think for a DC breaker to be non-directional; it must also be non-polarized. Yet a DC breaker can be non-polarized and directional.

Attached is a datasheet of what Aswich (a manufacturer) says is a non-polarized DC breaker.

 

[MattZN]

Hi all, I'm looking at the Taixi TXCM1B series breakers and the folks at AliExpress tells me it's non-polarized. I know some on this forum are not AliExpress fans and that's ok, but can I get an objective opinion on the Taixi TXCM1B series of breakers? I'm looking to use this breaker as my main DC disconnect for my battery bank. So this will isolate my battery bank from my inverters (2x EG4 6500EX 48V). I will be using BlueSea T class fuses as well for the battery bank (2x 2P16S Lifepo4) but want the additional functionality of being able to isolate the batteries from the inverters, and if I can have the isolation switch also provide over current protection, then that's ideal.

I also saw these Taixi breakers listed on Andy's site where he says it's quite good as a main battery disconnect. Perhaps I may be confused but my understanding is that for battery breakers, they should be non-polarized so they offer protection for both charging and discharging. The Taixi TXCM1B breakers have + and - symbols and also shows how which terminals the load should be connected to. Despite that, AliExpress is saying that they are non-polarized so I am reaching out to this forum to confirm based on the markings on the breaker, are they indeed non-polarized?

So I'm hoping that more knowledgeable persons than me on this forum can clear up this matter for me. Is this breaker non-polarized and will it protect for over current for both charging and discharging? I have the 600A double pole version. I've also attached the documentation which the folks at the Taixi store from aliexpress sent but I'm not seeing anything that says if its polarized or non-polarized. A note on the Taixi store folks....they're very responsive but I just want to make sure what I am being told is accurate before I place this critical breaker on my system. Ideally I would've loved to use the NoArk breakers that Andy uses but the store in Australia seems to not ship internationally.

Another question...is directional/non-directional, the same as polarized/non-polarized? Does directional mean polarized and non-directional mean non-polarized?

Thanks as always to folks on this forum for your guidance.

I had the same question and googling around found this thread. I decided to rip apart one of my 2-pole Chtaixi DC MCBs and I am including the pics here. This is the TXC65Z-60 B20. The two poles are marked "+" and "-", but they are EXACTLY the same. One is not upside down from the other... they are both oriented the same way even though the current direction is opposite for "+" vs "-".

I think that must mean that this 2-pole breaker is non-polarized, despite being marked "+" and "-". The question though is... is it non-polarized by virtue of being able to trip either breaker to cause both to trip (as they are tied together) ? i.e. breaking the ARC on one will break the ARC on both, generally. Or are they non-polarized because the magnet assist pulls the arc into the extinguishment plates regardless of current direction?

I'm an electrical engineer but I am not a circuit-breaker designer or an expert in breaker design, so I can't tell from the picture.

Pics: nameplate, close-ups, "exploded" views in proper orientation showing that both breakers are identically oriented.

--

Edit: additional information. It's a bit hard to see but on either side of the contacts, on the plastic wall, is a little compartment for housing a magnet. Two magnets per breaker. The compartments are covered by a little plastic piece in image 1094 which can be easily popped on and off. So basically the idea is for the magnets to clamshell the contact area. Two magnets per pole, one on each side.

HOWEVER, the Chtaixi 2-pole breakers don't seem to have the magnets. There should be four. There are zero. I have some Smseace single-pole breakers that are nearly an identical design, including the compartments, which does have two magnets. I think these are blowout magnets to assist with arc extinguishment, but I have no idea why the Chtaixi breakers don't have them while the Smseace breaker does. (EDIT: I read somewhere else that maybe non-polarized breakers don't have magnets, which makes some sense, but I have not been able to find any sort of official/company document validating that thesis. But then how is the ARC directed to the chute? Does it have to walk and elongate on its own?).

I have included IMG_1103.jpg showing the area, with the plastic cover removed, one with the Chtaixi (without the magnet), and the other is the Smseace with the magnet.

-Matt