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Plain breaker/fusing or Trip Shunt Breaker for Batrium...OR INSTEAD A CONTACTOR??
#11
(06-14-2019, 03:40 AM)Headrc Wrote:

I think I understand this Batrium diagram for just using the mosfets on the Watchmon 4 to control a negative sense shunt trip breaker but could someone correct me if I am wrong.   

With a 48V battery integrated with a shunt trip breaker that requires 48 volt supply for the shunt trip: 


1.  The positive of the battery connects to the positive supply voltage of the Watchmon4 with a 2A fuse in line and also connects to the positive side of the trip on the breaker with a 4A fuse in line.
2. The negative side of the battery connects to the negative ground of the Watchmon 4 and to one side of the negative sense of the trip shunt breaker
3. The other lead from the sense on the trip shunt breaker connects to the input A on the Watchmon 4.
4.  The output A on the Watchmon 4 connects to the negative side of the trip on the trip shunt breaker.
5.  The load (inverter) is connected through the shunt trip just like any regular breaker 

Is this all correct?  Is the power for the shunt trip breaker being supplied by that connection of the positive side of the battery and the output A of the Watchmon 4? 

Then as I understand it if I was to use a shunt trip breaker that required 24V to power it then there would be a resister in line on the positive side of the battery before it connects to the trip side of the breaker.  Is this also correct?

Then the software must be set up to determine what causes the breaker to be tripped?

And lastly, if all of what I have stated here is correct ...where does the load connect to the breaker?  

Thanks as always.

I do not have definitive answers and would also like answers - but let me share what I've read so far in hopes of encouraging someone more knowledgeable to correct/push the conversation ahead:

>With a 48V battery integrated with a shunt trip breaker that requires 48 volt supply for the shunt trip: 
>hen as I understand it if I was to use a shunt trip breaker that required 24V to power it then there would be a resister in line on the positive side of the battery before it connects to the trip side of the breaker.  Is this also correct?

You can either tap into your battery at the right place to draw 24v (or 12v) OR if you need a steady 24v (or 12v) you can add DC to DC converter that produces a steady output for a shunt-trip (if needed) regardless of exact battery voltage as it charges/discharges. 




>1.  The positive of the battery connects to the positive supply voltage of the Watchmon4 with a 2A fuse in line and also connects to the positive side of the trip on the breaker with a 4A fuse in line.
The [P] / 2amp is the pluse wire to the coil ...    The 4amp seems like a general fuse on the DC supply overall...   and it appears to enter the Shunt-Trip (to power other things?) but the [P] wire with 2amp would be the pulse to trigger the coil.

>2. The negative side of the battery connects to the negative ground of the Watchmon 4 and to one side of the negative sense of the trip shunt breaker
>3. The other lead from the sense on the trip shunt breaker connects to the input A on the Watchmon 4.
>4.  The output A on the Watchmon 4 connects to the negative side of the trip on the trip shunt breaker.
5.  The load (inverter) is connected through the shunt trip just like any regular breaker 
yes



>Then the software must be set up to determine what causes the breaker to be tripped?
On the software side ...   The  Hardware -> Expansion page will let you associate some control logic to "Output A" (shunt-trip pulse)  and "Input 5/A" (sense) like this:


Can someone explain what "Critical contact sensor - ON"  for Input 5/A  affects in the Batrium Software?   

Then the Control Logic -> Critical page will let you set things that will send the shunt-trip pulse when values go 'critical'....


OK - I hope someone can take this forward...  for both your sake and mine Smile
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#12
Thanks ... so even if you do not have an expansion board you use the expansion tab in the software to control the shunt trip?
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#13
(06-15-2019, 05:45 PM)Headrc Wrote: Thanks ... so even if you do not have an expansion board you use the expansion tab in the software to control the shunt trip?

Yes

In the 1st picture above, with Output Functions,  at the top left is shows the "Template: [ Watchmon4 + Expansion  ]v" dropdown
When I set this to the "Watchmon4" option the page changes to display Output A, Output B,  Input A, and Input B - e.g. the 4 things you would expect.
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#14
Thanks ...I have not gotten into the software yet other than seeing what others have done with it.   But looking over your response Offgrid let me ask about this:

>1.  The positive of the battery connects to the positive supply voltage of the Watchmon4 with a 2A fuse in line and also connects to the positive side of the trip on the breaker with a 4A fuse in line.
The [P] / 2amp is the pluse wire to the coil ...    The 4amp seems like a general fuse on the DC supply overall...   and it appears to enter the Shunt-Trip (to power other things?) but the [P] wire with 2amp would be the pulse to trigger the coil.

Looking at the Batrium Watchmon4 diagram:




The only thing I see that is relevant to [P] is the actual positive side connection for Watchmon.  If that is not where that  [P]/2 amp connects ...where does it connect on the Watchmon4?
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#15
(06-16-2019, 02:24 AM)Headrc Wrote: Thanks ...I have not gotten into the software yet other than seeing what others have done with it.   But looking over your response Offgrid let me ask about this:

>1.  The positive of the battery connects to the positive supply voltage of the Watchmon4 with a 2A fuse in line and also connects to the positive side of the trip on the breaker with a 4A fuse in line.
The [P] / 2amp is the pluse wire to the coil ...    The 4amp seems like a general fuse on the DC supply overall...   and it appears to enter the Shunt-Trip (to power other things?) but the [P] wire with 2amp would be the pulse to trigger the coil.

Looking at the Batrium Watchmon4 diagram:




The only thing I see that is relevant to [P] is the actual positive side connection for Watchmon.  If that is not where that  [P]/2 amp connects ...where does it connect on the Watchmon4?
Ah yes, ignore my previous comment.    Looking again - see if this make sense.

N and P power the Watchmon4 itself - in fact I power my Watchmon4 this way.   You can also power the Watchmon4 using USB from computer - but let's ignore that at the moment.    The 2amp fuse is  for the watchmon4 power circuit.    OUT A is the pulse circuit to the shunt trip coil with 4amp fuse on positive side of shunt coil.... but of course this would be shunt-trip coil specific.
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#16
Yes ...that is how I read it. Thanks. I am hoping I don't have to subject myself to trial and error on this .... but I may just have to get a shunt trip and give it a go.
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#17
I keep trying to make a decision on this whole thing ...and without starting a whole new thread ....let me ask:

Why is a shunt trip breaker better than using a properly rated contactor for disconnecting the load/inverter from a battery?  I can find NO 48 volt high current contactors that are new as opposed to buying a used breaker that I have to manipulate voltages from 48 volt to 24 volt for the shunt trip.  Pricing is about the same for the contactor when comparing to a used shunt trip.  So why would the shunt trip breaker be preferred.  There is a diagram on the Batrium web site for wiring up an NO contactor to the Batrium without the expansion board.  So someone must have done this.
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#18
Apparently, contactors have been known to weld closed sometimes with DC.
regular contactors also needs a few watts through the coil to hold closed continuously.
There are contactors for EV use that switch on with a pulse & off with another pulse.

If dropping the 48V to 24V for a shunt trip, use a resistor for simplicity, any fancy power supply etc might fail just when you need it most.
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Running off solar, DIY & electronics fan :-)
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#19
Thanks ...so it is a durability issue then when using contactors? Even though they are designed to be used for that continuous current.
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#20
(06-20-2019, 02:30 AM)Headrc Wrote: Why is a shunt trip breaker better than using a properly rated contactor for disconnecting the load/inverter from a battery? 

I worry about folks wanting to build complex systems without even this basic knowledge.

Breakers, without a shunt trip simply trip based on their ratings - the shunt trip allows another system, in this instance the BMS, to open the breaker - using a short pulse - which enables the breaker to be opened dependent on almost any criteria (such as cell volt, cell temp, time of day, outside temperature .... whatever you pick)
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