New 80 or 100 amp din rail breakers.

[Halfcrazy]

We now have 80 and 100 amp din rail breakers in stock. These carry our 150vdc ETL rating.

http://www.midnitesolar.com/productPhoto.php?product_ID=364&productCatName=BREAKERS&productCat_ID=16&sortOrder=17

[firerescue712]

Are these for pv only?  Or can they be used for 24vdc inverters? 

[Halfcrazy]

They have the same rating as all of our MNEPV breakers. If the inverter needs a 100 amp breaker than it should be fine.

Ryan

[firerescue712]

What is the max size wire the 80 and 700 amp breakers will accept?  Are the wire connected bare?  Or are wire connectors required?

[Halfcrazy]

Here is a link to it the one in the picture shows the copper buss bar bent to a 90 degree angle we ship them straight and you can tweak them at an angle if needed. http://www.midnitesolar.com/productPhoto.php?product_ID=364&productCatName=Breakers&productCat_ID=16&sortOrder=17

As you can see it is a box lug so no connector needed. I am trying to find out what wire size they will accept and will update this when I know that info as well as add it to the product description.

Ryan

[Robin]

I would not use the MNEPV100 breaker for an inverter. IT does accept at least 4AWG though. The issue is two fold.
The new din rail breaker is still just that.....a din rail breaker. That means it will be a bit flimsey when mounted. You need to use large cables for an inverter and large cables will tend to pull it off the din rail.
Our larger breakers like the MNDC125, 175 and 250 have a much higher interrupt capacity. That means that when the inverter fails and shorts the battery plus directly to the battery minus, it will still be able to open up. You will have very large amounts of current flowing through the breaker when an inverter fails. Somewhere on the order of thousands of amps. If the interrupt rating is too low, the breaker will weld itself shut and will not be able to open. Then the battery cables start to burn, catching the wall on fire which in turn catches the house on fire and burns you all up into crispy critters. Yup, I would opt for the larger panel mount breakers.

[firerescue712]

I have connected the MNEDC100 (corrected the breaker number on 10/17/12) to a Suresine 300-watt inverter.  I am using 4 gauge wire.  This has been running for a week with no issues.  I have checked the voltages on both sides of the breaker.  No variances.  I have checked for any heating in the wires or breaker.  None.  Should I still use another breaker for this inverter?  I am using the MNE250STM-L-240 as the load center for both my 24-volt and 12-volt systems.  I have the Classic 150 mounted to the MNE250STM-L-240.  I converted some of the ac breaker spaces to use the MNEPV breakers for the power distribution and PV input.  It is not a professional install, but it does not exceed any specs of the products installed. 

[dgd]

Our larger breakers like the MNDC125, 175 and 250 have a much higher interrupt capacity. That means that when the inverter fails and shorts the battery plus directly to the battery minus, it will still be able to open up. You will have very large amounts of current flowing through the breaker when an inverter fails. Somewhere on the order of thousands of amps. If the interrupt rating is too low, the breaker will weld itself shut and will not be able to open. Then the battery cables start to burn, catching the wall on fire which in turn catches the house on fire and burns you all up into crispy critters. Yup, I would opt for the larger panel mount breakers.

I can't quite follow the logic of using a breaker between battery bank or DC power panel and an inverter. If its main function is to protect against catastrophe when the inverter shorts +ve and -ve
then why take the risk of a breaker welding closed?
Should the protection not be a good quality fuse, say 400a rating? that will melt and open the circuit, perhaps in conjunction with a suitably rated knife switch where welding is unlikely.
Maybe it's just me but trusting any breaker in a very high current circuit seems rather risky.

dgd

[vtmaps]

Should the protection not be a good quality fuse, say 400a rating? that will melt and open the circuit, perhaps in conjunction with a suitably rated knife switch where welding is unlikely.
Maybe it's just me but trusting any breaker in a very high current circuit seems rather risky.

Fuses are not inherently better than breakers.  Fuses can fail to break currents that are outside their ratings.  Its all in the ratings.  The panel mount breakers are rated for their application.

A breaker (which can serve as a switch) is often cheaper than a fuse plus a disconnect switch.

--vtMAPS

[niel]

dgd,
if i'm reading all of this correctly in this thread.

if breakers were as bad as you think then many households that have breakers you are claiming them to be risky in their main service panels. although i'm sure it may be remotely possible for it to internally weld, i have never heard of such a thing happening. if you mean an external weld then know that some fuses that are mounted can work loose and short too. it's that a din rail may not be able to take quite as much of the physical strain upon it that large wires could impose upon the mount and this could easily be true of some fuse mounts. that means it isn't a question of if a fuse is better than a breaker, but rather a question of how much physical stress a particular breaker or fuse, as the case may be, may take. there are some fuses out there that i would trust a cb in a din rail over them and i'm agreeing with robin that the other types of breakers they have available are better suited for larger wires from a physical standpoint.

[Vic]

niel,

Agree,  and there is the other point that Robin mentioned about the higher Interrupt rating of the Panel Mount breakers over the DIN-Rail types.

And,  dgd,  a knife switch would still need to be enclosed to be Code,  and would need an over-center action to make/break qucikly.  The breaker should be much better,  as there are Arc extinguishing means shutes and often Magnetics for  DC arcs.  DC is very wicked stuff.

Would agree that the MN breakers represent a great value,  with combined OCPD and Disconnect function in a rated/Code compliant package.   Opinions,  Vic

[dgd]

dgd,
if i'm reading all of this correctly in this thread.

if breakers were as bad as you think then many households that have breakers you are claiming them to be risky in their main service panels. although i'm sure it may be remotely possible for it to internally weld, i have never heard of such a thing happening. if you mean an external weld then know that some fuses that are mounted can work loose and short too.

Ok I maybe was not too clear but I was referring to breakers in high current DC applications such as the DC  connection to a reasonable size inverter. My SW3024E can suck over 150 amps in normal use and if it failed and shorted the DC inputs then the current could be many times this.
I do not have a breaker between my DC distribution panel and inverter. I do have a 400A Class T dc fuse and a heavy duty rotary knife switch between my battery bank and DC distribution panel. I use DC breakers to my Classics and other 24v devices and DC breakers from my strings of PVs
A high current rated DC breaker may be convenient but expensive compared to a securely bolted down Class T dc fuze - just MHO

dgd

[boB]

A class T fuse between your battery and DC distribution panel should be fine.
A DC breaker between the inverter and distro panel is handy if you want to switch
off just the inverter without turning everything else off as well.

boB