What type of Circuit breaker CB to consider

Batrium

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Feb 17, 2017
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This question has been asked a few time, so this might be a great place to discuss here.
Not a discussionon Fuse verse Circuit BreakerCB but what options are available.

#1 must be compliant with relevant country regulations and guidelines.
#2 need to be DC rated within the voltage range, withnon polarized2 poleforboth POS, NEG terminals
#3 breaking current needs to be high enough to besuitable (> 10kA is advised for typical 10kWh 48vpack)
#4 maximum current amperes of CBto suit discharge and charge rates and equipment
#5 maximum current amperesof CB needs to be appropriate forcabling it is to protect
#6 remote triggering accessory to be a suitable voltage to control logic (typically pack voltage)
#7optional remote sense state to monitor the existing state of CB
#8 suitability for isolation conforming to IEC 60947-2

Every manufacturer has many different options. AC breakerssometimes also have DC ratingswith different characteristics. Alow cost option maybe to utilise an existing 3 phase second hand unitwith just 2 of the poles used. But confirm the product is suitable as AC rating does not mean itis suitable for this application.

Note+100A continuous CB are not small or light.
 
#3 breaking current needs to be high enough to be suitable (> 10kA is advised for typical 10kW 48v packs)

is the 10 000A an error or real?
 
For my project in Australia I used the following to suitthe cables, inverter and application.


image_texpfe.jpg

Schneider 125A 15kA Double Pole Circuit Breaker AUD$363
Breaking capacity:15 kA Icu - <= 250 V DC
Suitability for isolation: Yes conforming to IEC 60947-2
Dimensions (H x W x D): 81 x 54 x 73mm
Weight: 0.41 kg


image_fpbhlt.jpg

Schneider 2A 48VAC Shunt Trip Release AUD$105
Shunt trip release with OC contact IMX+OF
Width: 18 mm
Operational rating: AC-12 : 2 A at 48 V AC - 50 HzDC-12 : 2 A at 48 V DC

For those in Australia, If you are struggling to find units aboveI canpurchase on your behalf orput you in touch with supplier. Should be available from most electrical supply outlets.
 
ah, so its not the point of breaking the circuit but the max amp it can handle before the breaker breaks

v wouldnt say so, i just dont speak english as my first language and was unfamiliar with the term, not with the thing itself
 
MajStealth said:
ah, so its not the point of breaking the circuit but the max amp it can handle before the breaker breaks

DC currents when attempting to break the current willarc. Same asa welder, this too is a arc.Your circuit protection device needs to beable to protectin a fault scenario. Batteriesof this sizecan supply very large currents.

You should do more research to be familiar with this attribute.
 
I'll get the details off mine today ....
 
Batrium said:
wim said:
image_yzabxm.jpg

image_ouvtun.jpg

image_eskuqc.jpg

image_aqfrgc.jpg
Something like this one...

Looks good, On thephoto not sure if you haveconnected the remote trip to the BMS.

Yep, the remote trip is connected, with a extra relay to "inverse" the signal from the BMS, i have used the "battery OK" signal, this one is active if all is ok. The shunt needs a puls to trip. Need only to connect a signal to the BMS to report the state of the CB.
Working great, trips if there is a problem with cell votage, temperature, communication, ... i aim feeling soooo protected ;)
 
wim said:
Yep, the remote trip is connected, with a extra relay to "inverse" the signal from the BMS, i have used the "battery OK" signal, this one is active if all is ok. The shunt needs a puls to trip. Need only to connect a signal to the BMS to report the state of the CB.
Working great, trips if there is a problem with cell votage, temperature, communication, ... i aim feeling soooo protected ;)

Great work, there is already apulse method you could use. But maybe better ifyou wait tillthe next release 1.0.26 that has afew features that will make it even easier to follow and monitor the CB status.
 
Hey, I have been given 3 of these. Are they overkill and would they work with Batrium?

image_lretwv.jpg


image_ynuipa.jpg
 
Here I my Shunt Trip

image_dhgorn.jpg

image_mchmsc.jpg

image_yonlit.jpg

image_hgboqb.jpg

image_kjyiix.jpg
 
Just wondering what will govern the amp rating of the CB in this case.

Is it the max expected current draw for the system?

Working out which CB to get for my 100- 160 ah 48 volt LiFe system

Also, there are these shunts for sale $80 delivered to AU. Are these suitable??



image_dblcxm.jpg
 
The shunt trip is an addition to current breaker if you have such. For instance you can pair above shunt trip with an 63A or 125A double pole DC breaker and what the shunt trip then gives you is the addition to remotely break the connection by tripping the breaker.

Above looks ok as long as you have voltage to control it.
 
daromer said:
The shunt trip is an addition to current breaker if you have such. For instance you can pair above shunt trip with an 63A or 125A double pole DC breaker and what the shunt trip then gives you is the addition to remotely break the connection by tripping the breaker.

Above looks ok as long as you have voltage to control it.

Thanks. :)
 
hbpowerwall said:
Here I my Shunt Trip

image_dhgorn.jpg

image_mchmsc.jpg

image_yonlit.jpg

image_hgboqb.jpg

image_kjyiix.jpg

Did you purchase the Shunt Trip separately and have to physically attach it to the breaker? Or did it all arrive as one unit, ready to go? The Shunt Trip looks like a bolted-on addition in the photo, to me.
 
Shunt-trips for normal DIN mounted breakers like above are generaly bolt-on on the side. They just attach to the handle and will trigger that. There are premade units too though.

Batrium sells the Schneider brand and they are one of the better!
https://www.batrium.com/collections/miscellaneous


FiremanDIYPowerwall
The breaker will work yes but it has no shunt-trip what I can see? or did you just not photo that side? It says something about equipped with shunt-trip but i dont see any readings about voltage?
 
aatheus said:
hbpowerwall said:
Here I my Shunt Trip

image_dhgorn.jpg

image_mchmsc.jpg

image_yonlit.jpg

image_hgboqb.jpg

image_kjyiix.jpg

Did you purchase the Shunt Trip separately and have to physically attach it to the breaker? Or did it all arrive as one unit, ready to go? The Shunt Trip looks like a bolted-on addition in the photo, to me.

They are separate units which you have to connect yourself.
 
Howdy, thanks for the useful information. I'm a little confused by terms :huh:

1/ Is a CB the same as a Circuit Breaker the same as a Current Breaker?
2/ Does a CB automatically trip (switch off) at its rated current or is this just the max current it is rated to carry?
3/ If it does trip at its rated current do you need a fuse as well as a CB?
4/ If you want to trip your CB with other parameters do you need a Shunt Trip which you then control from an external control system (eg BMS)?

Basic questions but important! :)
 
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