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the right shunt trip?
#11
All electronics except the bms. IF you isolate that One you cant engage again safely since you dont know status Smile
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#12
(01-03-2020, 05:37 PM)daromer Wrote: All electronics except the bms. IF you isolate that One you cant engage again safely since you dont know status Smile
Interesting...   I thought disconnect should include Batrium (for example) - e.g. all electronics.   The fact that it tripped means 'manual attention' is required - e.g. go to it physically and inspect and then perhaps turn it back on and see what Batrium (for example) says...     If Batrium is still on/hooked to battery it will continue to drain power.

In my design, I'm planning to independently power the Batrium thru a local/nearby laptop USB. This has it's own battery backup - enough for several hours. I use the laptop as VPN/remote desktop portal as well for monitoring. If I don't get to it by then - as in out on vacation for a week - I truly want the entire system to be off.

Of course I'm interested in your perspective as my plans above might sound good to me - but be overkill etc. I know you've spent a LONG TIME on this Smile
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#13
I think it would be OK to include or exclude the BMS really… to a degree it might be personal preference, I can understand the argument both ways. 

I think it’s worth mentioning once it trips, it won’t reconnect without physical user intervention.  On the ABB you must physically turn the breaker off, then on again to reset the shunt trip breaker.  If the fault condition is still active (meaning the shunt trip coil is energized), it would immediately trip again until the condition is cleared.

The system cannot resume by itself regardless of if you decide to kill power to the BMS or not.

The only benefit of keeping the BMS energized is because you want to be able to connect to it for data or to investigate. Perhaps you want to maintain remote connectivity or keep the system on for the purpose of logging.  I can certainly understand being ok with the entire system, including the BMS being offline until you have a chance to investigate.  Considering most systems are quite large, I suspect the low drain isn’t really an issue, Personally I would keep the BMS online.
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#14
If you dont have the BMS running how do you plan to check what happened without connecting the battery? It can be the iNverter that is fryed...

You should have enough battery to power batrium for weeks. If you dont have that the battery built is not big enough for your system as a starter.


You should power batrium through the battery and NOT through USB. USB is only for setting it up and nothing else. Batrihm should be directly connected to the battery with only a simple fuse.
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
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#15
I was thinking about powering Batrium from an external power supply. So you can completly disconnect battery and still watch what is going on. Longmons are also powered directly from the cells. Those do not disconnect either!? What do you think about this idea?

For sure this is only possible when youre not offgrid completly. Also maybe not the best idea cause if you don't have grid power from any reason, you don't have the BMS running. Maybe I should think about my idea... :-)
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#16
Just discovered that batrium advices in their wiring diagram to wire batrium supply behind the breaker. See here: https://support.batrium.com/article/269-...-watchmon4

Unsure what's the right way now...
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#17
A bms should Always be powered Directly on the battery. You dont want it to get disconnected by the breaker. Therefore it should be powered by itself.

IF you dont have enough battery tonpower it for a couple of days your battery bank is way to small Wink

As you Said you want it to work all the time
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
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#18
You could also use the USB port as UPS system. This is what Batrium said. You can benefit from both possibilities then. Having the load unplugged from the battery to stop drain it and Batrium working all the time.
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#19
Yes but what do you Power batrium with? In My world your battery bank is the big source of power and to be honest IF you dont have enough energy in the battery for a week after the shunt trip tripped you messed Up Wink

There is No need to over complicate things. IF you are concerned add 5 more cells to your pack and your good to go. There should always be some juice left and that is more than enough to power a bms for a very long time.

Question: Do you remove your bms on your other devices you have when you dont use them?
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
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#20
A Batrium system (or other BMS units) typically draw so little power compared to the battery bank size, leaving it connected is not going to do the battery any harm - it's not drawing a few amps like an inverter idling, etc.
If you had a system you left unattended for long periods with no charge source, it might be different? (yes over charge protection should still trip the main breaker via the shunt trip too.)

I have a small separate breaker (10A) direct to the battery for electronics so (as mentioned above) I can still see & log the battery state during fault situations.
Running off solar, DIY & electronics fan :-)
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