One Circuit Breaker To Rule Them All!

This is my new favorite circuit breaker for battery banks! See why I think it's such a good value in this video. I'm using it with my off grid solar system between my 48VDC Battery Bank, and my inverters.
Video Building a Powerwall: • Building a Solar Gener...
Video setting up Powerwall at my friends home: • It's Alive! DIY Tiny ...
Amazon Affiliate Links:
125A DC circuit breaker, 2-pole: amzn.to/3q7IYDe
125A DC circuit breaker, 1-pole: amzn.to/3G6MK5D
100A DC circuit breaker, 3-pole: amzn.to/3G6KFqp
Din-Rail Box: amzn.to/3zDKoZG
Midnite Solar Bus Bars: amzn.to/3HKgB4d
Bus Bars: amzn.to/3HLp2fG
Resistors to pre-charge inverters: amzn.to/3zyXHKN
“As an Amazon Associate I earn from qualifying purchases.”
Affiliate Links:
Growatt 5000W Inverter with 450V MPPT Charge Controller 5000ES: signaturesolar.com/growatt-48...
Auto-Transformer, 5000ES: signaturesolar.com/growatt-5k...
EG4 Battery, 48V, 100Ah, 5.12kWh, LiFePO4, Server Rack design: signaturesolar.com/shop-all/b...
Waterproof EG4 battery: 48V LiFePO4 Lithium Battery with Bluetooth, EG4 Brand: signaturesolar.com/eg4-wp-lit...
Disclaimer:
My videos are in no way intended to be instructional "how-to" lessons. I am simply documenting my project for informational purposes. Property damage, personal injury, or death may result, even when following manufacturer's instructions. I cannot be held liable for such damage or injury. It is YOUR OBLIGATION to ensure that you are complying with any local and federal laws as well as code and permit requirements.
David Poz, LLC

[@Suicid344]

As an German electrician, no news for me. The trip curves are standardized, for a faster trip time, in household circuits, trip curve b is used, c is only used for circuits with quite long lasting inrush currents, like heavy motors or such. To trip instantly, on B curve breakers you need to have 5 times the rated current, for c breakers it's 8 times the rated current. So no wonder that it took so long till it tripped. And because of that you normally don't overrate the breakers, rather underrate them. In your example: 5kw inverter @48V is around 104A, so you would use a 100A Breaker.

[@mprelectrical]

Yes but you are taking AC, you shouldn't use AC breakers for DC.

[@Suicid344]

@@mprelectrical depends on the manufacturer. The most manufacturers allow DC currents, even have ratings in their data sheets. ABB S201 is rated for 72v DC and 253 AC, Hager states when using single pole 60vdc and when using 2 pole 125vdc. Lots of words but short sense: it's possible and depends on the manufacturer.

[@mprelectrical]

@@Suicid344 IEC 60947-2 GB14048.2

[@8uhayat]

Fantastic!. Your effort to test this in a real use scenario is highly appreciated. Keep up the good work David!

[@robertmyers4155]

Thank you for your lessons taught on this subject! I am not an electrician, but I have gone Vocational school over 42 years ago. I am now 61 years old and I am learning a lot about setting up my on solar panel control station thanks to you and other bright men like yourself on KZbin! I am so very grateful to you and others like yourself!😎

[@davef.2329]

Any relation to the late Milton?

[@bradfordsimms715]

You are a great source of information. I have the SS 48 volt battery and it is flawless.

[@MrRsalaza5]

Thank you David this gives me a good idea on how to create a shut off switch for the batteries on my 12000 watt 48V grow watt inverter.

[@offgridmgtowhomestead2520]

I have been using the single pole versions of these for couple years now. Been very, very impressed

[@edc1569]

There is a reason that ABB one is so large, it can reliably break huge fault currents.

[@diode30]

I wouldn't use these for this application. A 10kA interrupt rating is too low for the amount of battery bank you have. It would take some calculations to figure out the available fault current and then you would design your circuit protection based on that. At the battery bank I would use a UL 489 fusible disconnect that is load break capable with the appropriate SCCR and you could use a supplementary UL1077 after that if you can find one with the right SCCR. Likely your only option with a high enough SCCR would be another 489 fusible disconnect with appropriate fuses. Since DC never crosses zero, an arc fault event is particularly hard to clear, and without a high enough SCCR it may not clear at all. I don't mean to be a Debbie downer but there is a lot more that goes into circuit protection than matching the amp ratings of the conductors. If you do find a UL1077 breaker with a high enough SCCR you should probably select one that has a B trip curve.

[@AndyFletcherX31]

10KA at 48V means your wiring and series resistance of all your cells total

[@Philmoon69]

I agree 100 percent and want to add that DC breakers have arc suppressors in them where as AC have minimal Suppressors due to crossing 0V

[@sergeyblinov4957]

Concerning DIN-rail MCB's from well European-known brands, like Schneider, ABB, Legrand, Siemens, Moeller (under Eaton brand). General industrial MCB's ("AC version") from these brands have 80 V DC per pole rating. And these MCB's are successfully used in 48 V DC telecom power systems. Also, the more economical and efficient way (less voltage drop across protection unit), is to use European-style "Fuse-disconnectors". These devices acts as fuseholders and disconnectors for inverter Idle currennts).

[@yankey4]

Thank you so much man. This is GRATE INFO!!! You never disappoint! Now I need to buy some!! God Bless brother.

[@DavidPozEnergy]

Glad you like it. I'm going to be using these in all my upcoming builds.

[@saleenmustangs]

I just installed a system and used a 150 amp MCB, they are nice!

[@bentleyjarrard885]

Great video, looks like a nice, compact easy to use breaker. Based on the negative comments regarding the delayed trip function, its worth mentioning that many DC breakers are available in 3 versions, short, med and long delay. It seems that the particular model you tested was of the long delay variety. If different versions of that breaker are available a follow up video comparing trip times would be excellent. Speaking of breakers, I wanted to let you know I just posted a video with a 175A Midnight Solar Remote Trip breaker and PCB controller. The idea being to eliminate the golf cart style relay that has a large, wasteful stand-by current with the RT breaker and controller PCB which is connected to the BMS relay. I also posted a video with a latching contactor and control PCB that could be used to eliminate the always-on contactor.

[@SupremeRuleroftheWorld]

this is not a DC breaker.

[@billgalloway2320]

Good info David, thanks. I'm getting ready to build basically the same system as you. The growatt manual calls for dual 150 amp breaker/fuse protection at DC in. In my search I considered that 125 amp breaker but didn't like the over current trip curve, I really wanted to find Din mount 150 amp 10sec trip breakers. To be safe I think what I'm going to do is set up DC busbars and attach 150 amp ANL fuses running to inverter, those ANL's are huge, about 5 inches long, they atach with ring terminal.

[@NamesGolden]

get a look at the ANL fuse bars car audio people build. they just tap holes into copper bar. ugly but so practical it hurts.

[@excillisbank2611]

Bien, je recherchais ce test à plus de 125A, super merci David.

[@retrozmachine1189]

@davidpoz try testing the MCB for contact stability. Pass a stable current through the MCB and measure the voltage drop across the MCB using a multimeter while wiggling the lever. Also try testing the voltage drop with open / close cycles of the contacts. To be nice don't hot switch the contacts, ie under load, as this will degrade them. I've noticed that a lot of these high amp MCBs have quite poor contact stability with contact voltage drop varying from 10 to 80mV.

[@user-sb5vp3yu8m]

Nice video. You might spend a moment reviewing DC battery power concerns like short circuit current for your batteries as it relates to using a circuit breaker. In other words can the breaker stop a dead short in addition to an overload. I think it would help us understand. Also, fuses have the same kinds of time dependencies and charts. I think your video really sheds some light on these things and that we should all be thinking about them when choosing our circuit protection. SMA even notes in their manual that the inverter can’t produce enough current to trip more than a 20 amp breaker on the AC output side so the issue turns up on both sides of the inverter. Reasonably priced DC breakers are great

[@kennthbrowne7051]

Love your video them nice set up brother 🙂🙂🙂🙂

[@mikelyon7748]

really interesting and informative video

[@kevinhawthorne5257]

Great Video!

[@PvMLad]

Epic bit of kit

[@dustins4194]

Relatively Quick video!? 20 minutes! haha. I looked this one up and I actually bought one that is almost identical! It even has arc protection. I then added surge protection as well. I've never even had surge protection on my regular grid connection. I guess I just wanted peace of mind with the new solar setup.

[@offgridwanabe]

Never had much luck with the connector clamp in that type unless you use ferules the smaller wire comes loose easy but the breaker works great.

[@indy1234567891011]

Nice video, thanks man

[@AndyFletcherX31]

I've been using TOMZN TOB1Z breakers for a few years. 125A ones are rated at 250VDC and 10KA breaking current - more than adequate for 48V systems assuming the battery series resistance and wiring is less than 5 milliohms (you would have to be using some huge batteries and busbars to be below this). I would be cautious putting contacts in parallel as an imbalance could lead to annoyance tripping. One thing to watch out for with inverters is inrush current. My Victron 5KVA inverter has >40,000uF on the input and the inrush is brutal on breaker/switch contacts - use a resistor (500ohm/5W) across the contacts of the isolator/breaker to charge up the capacitors before closing it. Less damage to everything and less stress on the inverter.

[@EduardoRodriguezRocks]

hi andy, quick question why the difference with the resistors, they are all over the place on youtube, you mention 500ohm/5W and dave 100w/20ohm what should I get, I have a 7200w 48v battery and a growatt 5000w inverter

[@AndyFletcherX31]

@@EduardoRodriguezRocks it comes down to how much current the inverter takes when shutdown and input capacitor size. I have a Victron with almost 50,000uF capacitance so 500R will charge it within a minute or so. I keep my resistor permanently connected and the power rating is selected to ensure that it doesn't overheat if the load is constant when the breaker is open

[@AndyFletcherX31]

Couple of related points, above 125A you are into MCCB territory. These generally have higher Icu and voltage ratings than the MCB types. If you want higher voltage ratings then double pole switching is the way to go as there are two connections breaking when it operates giving better arc quenching and a higher voltage rating - as an example a TOB1Z 63A 1 pole breaker is rated at 125V but a 2 pole is 440V. The TOB1Z 125A single pole is 250V and the double pole is 600V. I'd always try to cautious and stay well below the maximum voltage rating of a breaker.

[@David.flet3747]

@@AndyFletcherX31 I have recently purchased (3) 13.5KWH batteries mfg'd by Lion Energy home sanctuary, I am looking for what inverter would be best for automatically switching "time of use" shifting w/out solar panels. (do not have a great roof for solar, only able to cover about 30% of our daily use) would like to power up my batteries during Non peak at very low rates and then use the batteries during peak rates for the 4-5 hours. I have an electric car and would like to recharge the 40.5kw worth of backup batteries I have during the 6 hour window from 12am to 6 a.m., would like to recharge batteries overnight and we have a backup generator that we can run or recharge the batteries during an extended grid down power outage. Any thoughts or advice would be greatly appreciated, the more I look into this, the more perplexed information I get.

[@AndyFletcherX31]

@@David.flet3747 I'm running off grid in the UK and am not fully aware of US based systems and regulations. I don't know a lot about Lion Energy products but assume they are 48V packs using something like the 280Ah Eve LFP cells with some sort of charger/inverter. I might be able to make some suggestions if you let me have more information on your full system. I suspect your challenge is controlling the operation of the system to charge/discharge on your required schedule. My contact is in the About section of my KZbin profile - feel free to drop me a mail.

[@stelaboys]

also 1 thing to note is in my victron setup if using dual or tripple setup you must not trip the ground on the DC side as all the units must stay connected via ground, no idea if its the same for your setup but expect its quite common.

[@WiSeNhEiMeR-1369]

HOWdy D-P, thanks for this TEST COOP ...

[@dapperdave2090]

nice... very informative... 👍😎👍

[@tripper1001]

Welcome to the DIN rail world. Outside of the USA, DIN rail MCB's have been standard for mains power in many countries.

[@chuxxsss]

Wish I had found these before doing tomorrows vlog. Went another way Dave, but I liked the ideas.

[@fullyelectric]

David, great 👍 content .. good test just one more test to always add when testing breakers is to also do a short circuit trip test .. that type of test is very valuable as most issues are with short circuits and most harmful... overload test is good but most if not very one running a battery system takes care to not overload ..again both test is important to know .. however the short circuit test has even more value ... Thanks again for everything you do ... rock on!

[@fullyelectric]

BTW everything is Chinese lol so you have to say “cheap Chinese” knock off .. quality US parts are made in China .. crazy the major quality difference from the same country..

[@DavidPozEnergy]

You are right. It sure seems like everything these days is made in China.

[@northlander1948]

@@DavidPozEnergy speaking of “American made” what are thoughts on the magnum brand inverter chargers? I’m between one of those and the new yellow low frequency mpp one.

[@derBomber69]

Well, I had the same problem as you. In the end I choose NH-2 fuse holders and a 125A fuse as well for an Victron Multi 3k 48v. These fuses can handle 440V DC and they have 25kA raiting when there are used with that high dc voltage. The ac rating is 120kA.........

[@lastcenturyclassics]

Top Job thanks

[@dudleykruythoffdiy]

Din rail breakers are what we normally use for our AC circuit breakers and DC breakers, however we also can use USA style breakers. GE makes din rail breakers. Basically on our island, St. Maarten Dutch Caribbean we mix and match European and American standards the best of both.

[@carlossantini]

Hey David, waiting for you great videos on Victron inverters (Quattro 120v). Thx u

[@wayne8113]

Thanks David

[@LithiumSolar]

Very cool!! I've been eyeing these for a little while now but haven't pulled the trigger on buying yet. They look very similar (identical?) to my 80A TOMZN breakers. One thing that made me hesitant is that, interestingly enough, there are no UL markings on it despite it having the rating. Additionally UL1077 is "supplementary protector" not "circuit breaker" and am guessing that's probably why. I'm certainly not an expert here, just something I noticed last time I was looking. It was cool to see it breaking such a heavy load though!

[@DSmartLife]

I think the Schneider C120N/C120H Acti9 MCB is a much better product than those Chinese ones. Although those are made for AC network type, they are also rated for 144V DC breaking (may be 10KA) and should come with most of the safety ratings. It's commonly available, cheap and Schnieder FAQ also says it can be used for DC system. I dunno if there are other limitations compared to dedicated DC breakers.

[@Rando32]

These also look like polarized breakers, which would mean if your inverter is also a battery charger and the charging trips the breaker you could have a fire. Only quenches the arc in one direction.

[@mtevans6196]

@@Rando32 If polarized breakers are wired incorrectly and turned off under load, the circuit breakers might not be able to extinguish the arc and the circuit breaker will burn out. This is for all polarized breakers.

[@mtevans6196]

@@DSmartLife Interesting commentary. Schneider, ABB, GE, Eaton etc are the big names -- but you fail to know is that Nader is the EATON of China. They black label for all the majors. These items are properly UL certified and I sell them to thousands of customers all over the USA with zero defects. Since 1999, I've had 6 units returned. That included MCCBs. You can get them from Amazon or through the US distributor.

[@DSmartLife]

​@@mtevans6196 You must be right about that particular brand. I shouldn't have generalized but there are several Chinese brands that we should be beware of. Regarding the Nader, I still think Schneider is a better choice because of the DC Voltage rating of 144VDC compared to 60VDC. For a battery that can go up to 58.4V DC there is not much room for tolerance, and we know that DC Arcs are much more dangerous than AC, difficult to quench even at this lower voltage. I don't know about the availability of Schneider MCBs in the US though. Thanks.

[@TheOnestoppctech]

I rather have it trip sooner. Thanks for the video!👍

[@djsmiley01]

They only have 10ka interrupting rating. Might be fine for a small bank, but with a huge battery bank its likely your going to exceed this with a dead short. It might just arc and continue to pass instead of breaking. Those expensive massive ones are more like 200ka. Thats also why class t fuses are expensive (higher interrupting rating) Have a look at NH fuses. Also has din rail holders available, more affordable and do have high interrupting rates. Commonly used in europe for high amp fusing

[@sergeyblinov4957]

We also use NH fuses in powerful 48 Vdc telecom power systems (up to 340 kW of 48 Vdc output). I think, it is economically viable to use NH fuses for everything larger 63 Amps (for 63 Amps or lower - we can use relatively cheap DIN-rail MCB's).

[@edc1569]

@@sergeyblinov4957 If you feed them with small enough cables then your fault current might be less than 10KA.

[@Rando32]

These are also polarized breakers this is dangerous advice to save dollars.

[@mtevans6196]

Bigger breakers are available

[@jonasgranlund4427]

Hi, I have a DC MCCB that have an Icu of 25ka and 250 Amps for my 32 kWh 48V battery, it looks very powerful but after the comment above that the big ones have 200ka I got a little nervous. Do you think I should look into NH fuses instead? Edit: and it is also rated at 1000VDC, so 48VDC is quite a bit below that.

[@SkypowerwithKarl]

Please note on the breaker shown, the safety certificate is “CCC” (China) not CE (European) or UL (American certification company). Does that mean it’s any less safe, I leave that to you. I’ve purchased the same brand shown but in AC and 63 amps. I found it impossible to have it safely clamp on stranded THHN wire and pass the jiggle test without it coming out. The only success was stripping twice the normal length of insulation and fold the wire in half before insertion into the terminal. I had to also tighten the crap out of the terminal screws. This concerned me so I junked the breakers and went with Square D for the AC side. I found some rail mount breakers on Amazon for my PV system that’s rated at 1000 volts and carries the “CE” rating(legit??). Those also didn’t pass the jiggle test without folding. I did elect to use those. As for those boxes, notice the mounting rail has two screws. Those screws are small and short. When you mount multiple breakers with large wires you can put a lot of stress on those screws to the point of failure. Try to form the wires shape before mounting the breakers. I drilled the holes out and bolted through with a fender washer on the outside. I also added spacer blocks for additional mounts/bolt through when you have a long rail.

[@wildwoodovensbbqs]

Bravo👏

[@arthurskudra50]

UL1077 breakers are not intended for this kind of use. I find it very concerning how long it took to trip when loaded well beyond it's capacity, not to mention how hot the wires and breaker became. This is a fire hazard waiting to happen, and an insurance claim nightmare. Just because there is a UL label does not mean its safe for any application. Furthermore, you normally shouldn't exceed 75 - 80 % of the rated current draw on any circuit breaker or wiring that the breaker is protecting.

[@dadaselectro4794]

Glad you said it :) You either need thicker wires or a faster breaker. In my installations i really do my best not to see any heating up like that. Then again, if everything is secured this will work but I just don't like it. I like big safety margins!

[@AndyFletcherX31]

Breakers have two types of trip in them. Thermal which he is testing here - will trip within an hour or so at 165% load and magnetic when it will trip immediately at 5 to 10 times overload (Curve C breaker). The first protects wiring from a persistent overload and the second from a short circuit. To do a safe installation you have to specify wiring taking into account how it is installed (surface/buried) and grouping (how many other hot wires are nearby).

[@AndyFletcherX31]

@@captainobvious9188 Erm, no. Power losses in the wiring is only a small proportion of the power in the system and thicker wires will have little impact on breaker heating. If there is a short circuit then a properly designed system will draw at least 10 times the design current to trip the breaker instantly (Curve C: 5-10 times overload)

[@theradioweyr]

Certainly looking for an option to these huge monstrosities of DC circuit breakers I have been forced to use, and while this is enticing, and while I might use them mounted to a rail on a piece of FR4 on a mobile unit or an experiment, I would not trust them in the system supplying power to my my house, protecting me and mine. If there is ever an insurance claim, I would not want to explain why I was running almost or over 200A of current on this small of cable.

[@NewTechChannel]

Agreed. My 63 AMPS breaker breaks instant when it hits 60 AMPS. But then again this is a German product and it has a A curve... I think

[@peteasmr2952]

Din rail is what Europe uses for their house circuit breakers, in the UK in plastic housing with built in din rails. I actually thought this was a standard EU breaker, interesting.

[@wim0104]

DIN rail is used worldwide in industrial control panels

[@peteasmr2952]

@@wim0104 Cool good to know.

[@AndrewStrydomBRP]

It's a metal housing now.

[@peteasmr2952]

@@AndrewStrydomBRP Oh interesting why the change?

[@AndrewStrydomBRP]

@@peteasmr2952 Fires in fuse boards are then contained, the specification also states that holes in the board must be sealed with fire proof foam or sealant.

[@TNW1337]

Not sure if you know this, That type of breaker does not support stranded wire, you can get terminals. Love your Crimpers!

[@yancymuu4977]

I'm not sure I'm ready to trust this breaker, as what keeps me awake is what happens if there is a dead short where one have have currents in the thousands of amps. Also there are sometimes two mechanisms in a breaker. One (a bi metal strip) for overloads that you have done a good job testing, and a second magnetic disconnect and arc suppression mode for protecting against a short circuit. Thank you for the great video.

[@vickipps6821]

Thank you David very interesting just would like ti ask you what you think of a Sunsynk 5kw Inverter & a Pylontec 4.8kw lithium battery as I trust your advice

[@moriartydrwatson3468]

You can get higher amp fuses (10-250+) for the blue sea mount and it works great for larger terminals and wires.

[@DavidPozEnergy]

I've looked at a few of the Blue Sea products. The spec sheets I've seen say "Maximum Voltage 48VDC". So those won't work for my battery bank which is typically between 48V and 58V. Is there another line from Blue Sea that has an appropriate voltage rating?

[@nicholaskeur]

@@DavidPozEnergy Class T rated to 160 VDC

[@pilgrimvalle]

@@DavidPozEnergy yes, I agree! go with the class T fuses. I use 400 amp class T fuses with 4/0 copper cables. that is the reason a lot of blue sea stuff is really not suitable for the higher voltage DC equipment. a lot of busbars also are not adequate... make sure you check the specifications closely for 48 volt LiFePO4 systems where the nominal voltage is closer to 56 volts. 3.2 volts x 16 = 51.2 volts but in reality, your LiFePO4 is being used at 3.35 to 3.55 volts most of the time. so 3.35 x 16 = 53.6 volts, and 3.55 x 16 = 56.8 volts. so 48 volt rated blue sea is not the way to go. breakers seem convenient but the cheap Chinese ones are likely a fire hazard! I was hoping it was a good one. do more research and do more videos. I like your work. I have 96 280ah LiFEPO4 cells cycling.

[@robertmiddendorf1519]

The circuit breaker I like is the one that works.

[@struc5810]

I have a Chcyzo brand breaker sitting right in front of me rated at 125vdc / 250A that looks just like that one. Was going to use it for a disconnect switch on my DIY LiFePO4 battery bank, but decided to go a different route. I *believe* it has a 10k AIC rating. Maybe in the future that will translate into larger breakers for that particular brand.

[@SupremeRuleroftheWorld]

you should not use it because its AC only. DC breakers are very different internally. AC breakers on DV loads will burn out.

[@struc5810]

@@SupremeRuleroftheWorld You should read more carefully. I said the breaker is rated for 125vdc

[@fredsilva4949]

David you surely know about line fuses, every modern car has one on the battery cable.

[@edc1569]

Thing is most of us aren't looking for protection from a mild overload - which isn't really possible unless your breaker is too small for your inverter - we want to know if it'll save our bacon when we short the pack at 53V....

[@diysolaradventures7894]

I cant wait to see u install the din rail box and breakers im trying to figure out how did u install the solar edge transformer with that din rail box instead of a sub panel i rather use a din rail box with neutral and ground to create the 120v i need i seen the other video but u didnt go into full detail on the connections

[@RJ-cc1fz]

Instead of line/load sides, should the breaker be a bidirectional type for charging and discharging

[@marklawrence2539]

Hi Dave - New subscriber - refreshed by some of the items I see in your content . . . have you any detail on the 100W 20Hohm? inline resistor? I assume this smooths capacitance loading sparks on connection, also I see Many of your project boxes with warming lights added, are these to advise you of faults, or of correct running? personally I would not want that overload current heating wires and components for that duration and would prefer to apply simple DC bimetallic circuit breakers which act more quickly and are generally tripped by +10% of current rating, keep up the good work :-)

[@SetitesTechAdventures]

Bro you should consider investing in a thermal camera. Great video.

[@drbytes68]

I think all of europe has their distribution and breaker boxes in DIN rails, I have it and it's so easy to swap stuff in and out

[@jschaeke]

indeed quite ubiquitous and standard for switchboxes in here in Europe to use DIN. Seeing those American electrical videos surprised me in the beginning how differently it's done. Like the use of metal pipes, light switches with huge borders and often actual toggles, speaking of high voltage/power if it is 220v where we think 380v, different coloring of cables (blue and brown here)...

[@drbytes68]

@@jschaeke Yeh first time I saw a US breaker box I thought it was some old house or something custom, it looked like something my grandparents had before the Germans bombed it to where it belonged. Pretty surprised it's basically standard over there. Nothing about the US electric code makes good sense but hey.. seems to work just as well I guess. Until you actually need to power something beefy.

[@gf3803]

Is that Nader circuit breaker polarity sensitive do you know? Is there any documentation on that, or any markings on the breaker itself to tell one way or another? Would be interested in using one between an inverter/charger and my batteries but it's bi-directional flow, so would need it to be polarity insensitive.

[@ilanozana9652]

If the red indicates the measurement so you are in the unidentified state ,that is from 1.5 to 1.8 like times In. The mcb is protecting the wires so they should be rated 1.1x In of the mcb.

[@dineshkumarramasamy5227]

Those terminals are called tiger cage terminals which is capable of keeping even a stripped-uncrimped wire tight and snug fit.

[@nicholasthon973]

Have you calculated your fault current and compared that to the breaker rating? That’s important to know.

[@Kosmonooit]

Gewiss and hager make decent 100A and 125A DC DIN MCB 2P Circuit Breakers ... relatively expensive but good. Chinese ones I have tried are rubbish (ie Tomzn), smaller rated ones are okay (ie 60A 2P Chint). We use DIN rain system now all over, distribution boards etc. 2P are generally used as Isolators as well. Paralleling a 2P one to increase the rating might work but is questionable, not good practice imo. And you must use DC rated ones for DC there is a difference to the AC ones. Some are rated for both AC and DC.

[@stevematthias8438]

David--I just purchased 8 -230 watt panels, I need some of your knowledge for other component. Steve

[@lysol7204]

Is it bidirectional? Theres vid showing some non bidrectional breakers catching on fire! If its used with an all in one inverter it will flow both ways during charging and inverter use.

[@woodydroneson]

Thanks for the video, I am probably like many others having trouble working out two things. 1. The Circuit Breaker / Fuse size needed between Batteries and Inverter and 2. The Circuit Breaker / Fuse sizes needed between the Solar Panels and the Charge Controller. I have a Eco-Worthy 24v System 1360w total panels (8 x 170w) and 4x12v 50ah batteries. I would like to add in MCB / Fuses to ensure the best safety, the instruction manuals for panels, controller, inverter etc are a bit vague and suggest this, but do not state the sizes needed. Any help would be appreciated, Thanks :) I also presume that the Inverter should be grounded, which the manuals do not state, but the UK has Earth Connections and Europe etc do not, so maybe its less important, but I will be earthing the case anyway :)

[@UNLOCKCONNECTIONS]

If you connecting the panells in series to use on a MPPT then look at the back of the panels and see what amperage each is rated and add the amperage, so for example if each panel is 5amps and you have 4 of them then you'll need 20amps breaker

[@woodydroneson]

@@UNLOCKCONNECTIONS Thanks, I have researched further and it appears that the Kit/wires/wiring diagram is incorrect and would result in a fire! I have decided to buy a 4-string combiner box with 15amp-rated fuses and a final 60amp fuse/ breaker. Panels are rated at 9.89amp max so 2 panels give 24v 340watt and 9.89amp with another 3 sets of panels so a final amperage circa 39.56amp. The Kit just had Y connectors with the diagram with what I believe to be only a 30 amp rating! Eco-Worthy UK customer service is diabolical! I need to keep the panels as 4 sets of two due to the movement of the sun as throughout the day they will slowly become shaded, so I have grouped them in the best possible locations to maximise the efficiency of the system. Thanks again for your reply it helps confirm my research so far.

[@joepah51]

Great video.. Would your PV fuse protect your downstream equipment from a lightning strike? Thanks for demonstrating the C trip.. Doesn't look like that breakers works very well.. Took 10 minutes to trip at 50% over capacity of 125 amps..

[@AndyFletcherX31]

The breaker performed correctly in the test. Check the data sheets for "overload" condition for circuit breakers. They are designed to protect the wiring and have a carefully designed characteristic. In general breakers have a tighter performance curve compared to a fuse.

[@offgridmangogrower]

Any great experience with a certain brand lithium battery?

[@majidjan3990]

My very important question

[@pierofranchi7489]

Hear is a question ??? if you are using two or more rack batteries with built in breakers, would you still use a breaker on the cable from the batteries to the inverter that can handle the combined load ???

[@GoCoyote]

All circuit breakers have a "percentage of capacity" rating for normal operation. If no rating is specified, they are rated for 80% of capacity for continuous use. This means that a standard 100A breaker can function under 80 amps of continuous loads. If a 100A breaker is rated for 100% continuous loads, then it can handle 100Amps continuously. This is important, since an overloaded breaker can overheat and malfunction.

[@UK100Adam]

Was the heat internal to the MCB or due to the contact resistance on the terminals? As even just 1mR contact resistance at 150A is 22W. Let me know you thoughts. Thanks.

[@nagylaszlo8825]

Hi! I have a question. Is this MCB DC MCB with Polarity? It seems to be that. So, what is happening in that case when you have mppt-inverter togethe (2 in 1)? Because in this case the load side and the line side change by the swiching between charging and discharging operation. As a result: The MCB will be unable to turn off the current and extinguish the arc during an overload or short circuit conditions, causing the circuit breaker to burn out. The arc is pulled from the contact and into the arc extinguishing chamber by a tiny magnet in the polarity DC MCB. The magnet will lead the arc out of the arc extinguishing chamber and into the MCB mechanism if the current running through the device is in the other direction, harming the equipment.

[@Row23]

Poz, the load side to the inverter? Line side to batts? Not the other way around. Does it matter?

[@micbanand]

I would go with B rated curved relay :) its what the code says to use i my area

[@Dutch_off_grid_homesteading]

heya nice test I only didn't like to see how long it takes disconnect the load

[@jimTal001]

Hello David, Based on all the comments below (mostly negative) are you still using this breaker between inverter and batteries? I know that SS is still selling them for this purpose because I just purchased it.. Thanks

[@diyEVguy]

@DavidPoz @LithiumSolar: Be very careful with DC breaker polarity. Connecting the breaker using a reversed polarity causes the arc to be pulled into the wrong direction (away from the arc chute that is supposed to extinguish it) so the breaker can catch on fire. The "LINE" and "LOAD" markings *do not* always corresponds to "battery" and "inverter", respectively! For example, connecting the battery to "LINE" and inverter to "LOAD" can be incorrect for some breakers that were originally designed for the telecom industry. In your case, you may have done it correctly, but this procedure should not be blindly copied and applied by your viewers to breakers from other manufacturers. So thoroughly read the documentation of the breaker at hand. And check the interrupt current. A smaller breaker may mean a smaller chute, extinguishing only smaller arcs, allowing only smaller dead shorts, roughly speaking. Please correct me if I am wrong.

[@stefanvanzyl9090]

Hi Johan, could you please elaborate on when line and load would be reversed? Circuit breakers should not be a first line defense for over current protection, so the line side should probably always point towards the battery side - since the inverter/charger could never supply the same magnitude of short circuit current that a battery could. Also, having a 10kA AIC rating for batteries seems pretty low in my mind, but apparently to achieve 10kA with LFP type batteries, you require about 900Ah of cells in parallel - don't take my word for it and do your own research! I use gR type cylindrical fuses to protect inverters, which have a 200kA rating and cost less than twice the price of general cylindrical fuses at about $10 per 100A fuse.

[@ai4px]

@@stefanvanzyl9090 maybe his comment about telecom has to do with negative 48v used at telecom sites?

[@LithiumSolar]

The specifications sheet for this breaker shows how to connect it for use with DC. He has it connected correctly (inverter on the load terminals).

[@diyEVguy]

@@stefanvanzyl9090 @DavidPoz: My explanation with an actual example was deleted. Any idea why?

[@diyEVguy]

@@stefanvanzyl9090 Example: Take a CarlingTech 125A DC breaker (CX1-B0-14-912-32A-10C). It has the terminals marked as "LOAD (+)" and "LINE (-)". If you want to install the breaker closest to the battery positive, because the battery negative is grounded, then the battery positive should be connected to the breaker's "LOAD" (!) terminal. I verified this with one of their application engineers and I verified it myself by reverse-engineering the breaker because we all make mistakes. So in this case it seems more important to look at the polarity markings "(+)" and "(-)", rather than "LOAD" or "LINE", because the latter two can be industry-specific. This breaker was designed, according to the same CarlingTech engineer, for the telecom industry, where the positive battery terminal is grounded to prevent corrosion, so this breaker is most likely intended to be closest to the battery negative terminal. Bottom line is that the "(+)" side of this breaker must be connected to the circuit end with the highest voltage potential (i.e. the battery positive) so that the current-to-be-interrupted (in most cases from battery discharging) flows in the correct direction for the magnet in the breaker to direct it into the arc chute.

[@stevemorris3710]

Hey USA, welcome to the 1950'S, when DIN rail really took off in the modern world :-)

[@nicholaskeur]

Yep Was going to comment the same thing LOL

[@blainecelestaine4543]

I clicked like when you said test. 👍

[@tm510a]

Question, a 5000 kWh inverter is recommended to use a 250 amp breaker. I'm I wrong? Thanks much David for your channel it has helped me a lot.

[@billgalloway2320]

The manual states 150 amp dual breaker for each inverter at dc in

[@randycarter2001]

You often have to research under what conditions the ratings are derived. Foe example your typical NEMA 5-15 outlet has a 15 amp for 10 minutes rating. In reality you have to derate the outlet 20% to 12 amps for a continuous load of 1 hour or more. So your 250 amp bus bar may be stated for 10 minutes momentary not continuous loads.

[@solarhome_ru]

No problem with 12V. Can you trip it at 60V and rated 100A?

[@erikvandamme6915]

I don't understand of Circuit breakers or fuses in parallel! What the current splits nicely in two?

[@jamesmodra]

Hey David, is that breaker non-polarized, can it detect current overload in the opposite direction too, like solar charging the batteries at 150+ A through the breaker so you get current protection on the flow in both directions?

[@fauxque5057]

I have the same question

[@uncledoug9934]

I have a string of PV modules in series producing VOC 303V with 8.73 amps. Could one of these 400or 500V MCB be used as a interrupter since it is a one way circuit?

[@roberthousedorfii1743]

I've used Blue Sea 48V breakers for everything so far, on the output side of my 24v system. Probably not good, but I figure they will break for over amp conditions, no matter what. They work well ,actually, as switches, also. I'm thinking a 48V 20 amp breaker, will cut out at 24v, 40 amp? Perhaps I should run some tests...

[@sergeyblinov4957]

48 V 20 Amp breaker will cut at the same current in 24 V dc circuit, as in 48 V dc circuit. This overload current will be higher, than rated 20 Amps for a standardized "addition": 20 A + (specially determined value). This value, according standards, depends on allowable time for flowing such overload current. Overcurrent trip function is independent of circuit voltage. This voltage is maximum voltage for correct CB operation and for arc extinguishing on CB's contacts during fault crearing. We cannot exceed this voltage value. So, your 24 Vdc system will work fine with 48 Vdx breakers. If you need to protect a 40 Amps circuit, you need to install a 40 Amp breaker.

[@thomasmoore4576]

I see you're using that Jupiter inverter I'm fairly sure that that is a modified sine wave when you run like your refrigerator with those and it makes the motor hum will that burn your motors up over a period of time or are they fine and the circuit breaker you was using if it's going to get that hot with the wires getting that hot and you put it in a plastic box with a DIN rail that is that going to get so too hot and melt the box to wear stuff could come loose looked awful hot to me thanks I would like any input especially about the modified sine wave inverter

[@tomforti]

Do u have a link for the terminal to connect multiple batteries in parallel?

[@budmartin3344]

I do not see any DC rating printed on the breaker at all. Does it have arc chute and magnet (you can put screw driver to locate the magnet inside) for DC arc suppression?

[@eliotmansfield]

Here in europe pretty much everything has been on din rail for many years if not decades

[@ellemarta]

Hi nice video I have a question to ask do you need to add on safety fuses if the battery are Pylontech or Eg4 lifepower thank you..

[@DavidPozEnergy]

I added a fuse to my battery bank. Here is the video: kzbin.info/www/bejne/d2HFonain5qoqMk

[@DIYDaveT]

What is the model number of the ABB breaker you used? You said it was 300 amp. Was that total input (implying 100 per pole) , or 300 per pole?

[@sonnenklang6925]

did u test if it breaks without arcing at 48-60V 125A+ dc= ist that a polarized magnetic quench? thx ;)

[@smacospasovski5123]

All 3 links for the breakers say currently unavailable , nice one

[@ralph72462]

Hi been watching your videos. I am building a portable 48v system and space is important. Even though the circuit didn't trip at the intended amperage I could probably use it a disconnect switch since I will still have an inline fuse that will trip if my current is over the intended amperage rating. At least that's my plan but I could use all the advice possible because even though this is not my first Solar generator it is my first 48v system and it's a lot more serious than my small 12v one. Will check your links to try to find these components been doing a lot of purchasing and searching on Amazon but like you mentioned correctly some of the stuff is very questionable and a fire because of a cheap Chinese part is not acceptable so I want to make this build which I have already started but I want to be safe and know it's a Solar generator I can count on in an emergency power outage rather than a potential bomb... lol So I appreciate your videos and anything you may share. Thank you. Your videos are very helpful.

[@DavidPozEnergy]

I like this circuit breaker and have used it on projects. Actually, after I made this video, several online retailers have started selling this breaker for solar projects. For example, Signature Solar sells it with a paralleling bar: signaturesolar.com/nader-dc-circuit-breaker-60v-200amp-with-enclosure/?ref=4_rHcgZ9x-TiF- Good luck with your build.

[@ralph72462]

@@DavidPozEnergy Thank you this was very helpful.

[@bernardl8941]

Ello the 2big Yello inverter is on fonction?

[@ai4px]

David, do you know if Ben has every run those sunny islands if off grid mode with a SolarEdge inverter?

[@DavidPozEnergy]

I don't know. I've done it with Solectria.

[@DanBurgaud]

13:27 I noticed you did not put terminal lugs on these. And I wonder if we need too...

[@jonphanspromotions]

you got me confused for a second with all the blue and red wires from the batteries. You should have used all reds and all blues for negative. Other than that, it was pretty easy to follow. Thanks

[@pawneeoffgrid2614]

I curious why you would break both the positive and the negative. Does it still give protection if you purchase the single pole breaker and break just the Positive wire?

[@ssoffshore5111]

I had the same thought, am I missing something???

[@ARepublicIfYouCanKeepIt]

@@ssoffshore5111 You're not missing anything. It's only necessary to break a single leg (+).

[@fernanduslewis2101]

why did you put e 100 watt resistor on the negative block before you hooked it up?

[@joeboxter3635]

I might not understand your setup, but you don't need a breaker between battery and inverter unless you are using breaker as your "cut-off". If there is a short in the inverter, the inverter internal breaker will go off and prevent over draw. Well at least most high end inverters have this safety built in.

[@NewTechChannel]

And if your inverter fails a little fire starts. Not a big problem at all. Why not be safe? for 30$?