Test of multiple trip type circuit breakers.

Skip to first unread message

Dacian Todea

Feb 27, 2021, 7:25:44 PMFeb 27
to electrodacus
Finally I took some time to do a test on all the tip circuit breakers I had and some new ones I ordered to test so that those that want to use type 5 for extra level of protection or those that just have an inverter without remote ON/OFF or difficult to implement and want to use a shunt trip circuit breaker to cut off the inverter in case of low voltage then they will use the type 2 to trip the breaker and will need to add a capacitor recharge circuit that needs to be enabled before reconnecting the breaker manually in case it ever happens to be tripped.

EXT IOx can of course not drive the trip coil directly so you will need a normally close solid state relay like the CPC1705 (tho based on spec 3.25A is max current and also peak) so maybe not good for many of this unless you parallel two of them. Next option I see maybe easier to use for some as it requires no soldering is the DC60S5 this has 5A rating but 10A peak for 10ms so it will work with all trip coils in this test.

Below a few photos of the tested breakers.

This large SafeSave breakers are both rated 315A per contact and they have 3 contacts is just that the one on the left is the S model and the one on the right is the H model that is taller and has higher max interrupt current capabilities. But this things are expensive for most people and there are many brands that have similar breakers. 



The Langir is a great breaker but the trip shunt I found is not matching this breaker not sure witch one if there is one will match the Langir. May need to ask the manufacturer. This will not fit mechanically but after I cuts some plastic parts on the trip shunt I can put them together and it will work to trip but is not usable as they need some guides to stay properly connected together.

This are some very old breakers and not good quality at all but the trip shunt works likely with many similar breakers that may be better quality.
They of course fit great and trip as expected.
I had high expectations from this inexpensive TAXI breaker but the inconsistent contact resistance will not allow me to be able to recommend it.
You can see the diagram showing there is a contact that will open as soon as breaker is tripped disconnecting the coil and that is the case for all of them except the MidNite.
The thing next to is the trip coil (I got an extra one as I have another Taxi breaker and that has more consistent contact resistance so not sure why this is different).
A look inside the Taxi breaker.
Unfortunately MidNite is the only one that has no switch to open when breaker is tripped so that coil is disconnected thus this is not usable in almost any application so not sure why they did that. But this is made by Carling for MidNite so maybe they have a similar mode but with coil disconnect switch as if so this will be a good quality breaker.


If you use or know of other breakers with trip coil circuit let me know and I will take a look.

Below are the current curves for those interested. I tested all of them at 18V and they all work at that minimum voltage (most are guaranteed to work at 19V)  then for testing the current I supplied them with 24V but there was a 0.5Ohm resistor in series used to measure the current so there was some voltage drop on that.
Current is displayed correctly as 1A per division.

Below is the graph for the large 3 x 315A SafeSave breaker the S version but the H will be the same as it has the same trip coil. 
Below is for the TAXI breaker not that different form the larger 315A one above and they are both noisy when they trip so if you do not expect that you may have a hart attack. 
The Midnite requires only 1.7A so very efficient and also quiet to bad it will never stop the current trough coil so coil will get damaged if not disconnected withing a few seconds.
Below is the Fen Li MX that disconnects the Jieke breaker and it works very reliably to bad this sort of breakers are made by so many and is hard to find a quality one.

Below is the iMX+OF disconnecting the Langir but they are just not designed for each-other so I may need to search for a different MX shunt trip as Langir are fairly nice breakers and at a very good price.   


Apr 4, 2021, 8:01:12 PMApr 4
to electrodacus
Hi Dacian,

I failed to understand what the Midnite Solar breaker lacks: 
"The Midnite requires only 1.7A so very efficient and also quiet to bad it will never stop the current trough coil so coil will get damaged if not disconnected within a few seconds".

When the Midnite solar breaker breaks is it not interrupting the current path?

Could you possibly elaborate for us?



Apr 4, 2021, 9:28:27 PMApr 4
to electrodacus
   Hi E4M,

      It disconnects the power (Load) contacts by activating a coil which releases the mechanical part that keeps the breaker On. 
Usually it takes a pulse of less than second to do that. Most beakers have (or rather should have) a switch that disconnects the coil too. This way the current thru coil is off as soon as breaker is off. 
   To protect the coil it can be supplied with (+) not from the battery but from the load side of the same breaker so when it's off current thru coil is off too.
But that's just my theory, maybe i'm missing something so let Dacian confirm first.   

Dacian Todea

Apr 5, 2021, 2:14:34 AMApr 5
to electrodacus

All other breakers tested except for Midnite has a switch in series with the coil and that switch will be opened at the same time with the main breaker switch (you can even see in the oscilloscope graph that current through coil is not stopped and I did that manually) If current through the coil is permanent the coil will burn within seconds.
In some application it may work just fine to have the coil supplied for the Load side of the switch but if you want to disconnect a charge source then there will be voltage on both sides of the breaker and coil will be damaged.
Is not visible in the photo but there is a microswitch that is connected in series with that coil from the TAIXI breaker and same is true for all other except for that particular Midnite. So Midnite will just not work for this particular applications where you need to disconnect both the Loads but also charge sources so the one that will disconnect the charge sources will have a damaged coil maybe even catch on fire.

Steve Marotta

Jul 23, 2021, 3:04:24 AMJul 23
to electrodacus
Hi Dacian,

Just thought I would get your thoughts on the below photos.
Have been looking around for MCCB's with trip units as per your thread here and managed to get these photos from one of the manufacturers.
At least the arc shutes are in there :), I do not think I can see the shunt trip actuator in this one, it may not be installed.

This shows the 100A version I would be getting the 200A


Im not sure if these are DC though the markings are pretty minimal
The brochure also does not mention DC...

It seems like I may go with either these or the Taixi MCCB's


Dacian Todea

Jul 23, 2021, 11:57:32 AMJul 23
to electrodacus
Yes the trip coils are not installed in those photos.
All this have similar construction and I looked at this brand but it was just more expensive and not any better quality.
Any of this 400VAC rated breakers will be capable of handling the max 50Vdc available in a 24V battery system.
They look like just thermal breaker no coils for fast sort circuit protection like the Taixi branded ones that I showed. This may actually all be made in the same factory both brands end in "ixi"

Steve Marotta

Jul 23, 2021, 4:50:34 PMJul 23
to electrodacus
Good point about the fast trip coil, was the Taixi one your purchased the same model as https://www.aliexpress.com/item/4000537721228.html link that you provided in another thread?

Dacian Todea

Jul 24, 2021, 12:57:53 PMJul 24
to electrodacus
Yes that link is to the same store I purchased mine.
Reply all
Reply to author
0 new messages