Need Some Help

Thanks @Justin Laureltec! Here is the link to the 40amp on the POS side of the SCC: T Tocas 40 Amp Surface-Mount Circuit Breakers with Manual Reset, 12V- 72V DC, Waterproof (40A) https://www.amazon.com/dp/B07D7VHJYK

thanks for catching the incorrect wiring on the shunt!

Johnmahon said:

Thanks @Justin Laureltec! Here is the link to the 40amp on the POS side of the SCC: T Tocas 40 Amp Surface-Mount Circuit Breakers with Manual Reset, 12V- 72V DC, Waterproof (40A) https://www.amazon.com/dp/B07D7VHJYK

thanks for catching the incorrect wiring on the shunt!

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No problem! And eesh, yeah the T-Tocas. Well... man... it's your call, it might work fine, but I'll go on record as saying that I wouldn't trust that any farther than I could spit a rat. The Buss breakers are around $20 or so more (depends on who you buy from) but they're manufactured to spec and they're trustworthy.

@Justin Laureltec - rereading your reply... the Load in my original photo IS the inverter... If this is my intention, what is the correct wiring? My definition of "Load" is the 24V 2000W inverter. Also assuming that I will rewire the negative shunt to connect to the battery directly as you prescribed.

Thanks!

John

@Johnmahon ahhhhh nuts, then that's a problem. Victron forbids the use of a BP to directly disconnect the main DC line of any inverter. You can use the BP to trigger the remote on/off of the inverter (if so equipped), but you must not use it to connect/disconnect the DC line. See the updated BP user manual for the BP100 here, or the Smart BP100 here.
So, in this case, assuming your inverter has a remote on-off trigger, you connect the main DC POS of the inverter directly to the battery and then you run another DC POS to the BP, then the "out" of the BP goes to the trigger input. Then you set your voltage cutouts and when the BP senses low voltage it removes the POS trigger to the inverter, turning the inverter off but not disconnecting the main DC line.
The problem is that the inrush current of the inverter charging its caps will trigger the short-circuit alarm of the BP... which is resettable, but repeated occurrences of this eventually damage the logic of the BP and it stops doing what it's supposed to do. There are also occurrences in which the inrush current, being far greater than the rating of the BP, overheat the FETs and cause damage that way. Whatever the case, direct connection of a BP to an inverter is expressly forbidden at this point, since -one way or another- it destabilizes and will eventually damage the device.

@Justin Laureltec - Do I even need a battery protect when I have the Battery Monitor and the Smart Charge controller...? Perhaps that is overkill, especially since I will be using the inverter to simply power small power tools (mainly to charge their batteries) and internal LED lighting in my shed. An occasional heat gun from time to time when making wire connectors.

@Johnmahon I mean... not really. TBH the only point of a BP is to let you run your loads and walk away, without worrying about your battery voltage, because you know it'll shut down when it reaches the set threshold. As long as you keep an eye on the voltages yourself, there's no reason to use one.

I mean, they can definitely be used for other things... for instance I use a Smart BP65 in my truck to automatically turn on my driving lights when my engine is running and automatically turn them back off with a 2-minute exit lighting timer after I shut the engine off. They're super cool as a programmable VSR. But in terms of actual battery protection, nope, just keep an eye on the voltage yourself and you'll be fine.

@Justin Laureltec - that's what I figured... Stay tuned... Got all weekend to get this thing up and running! Happy New and thanks for the wisdom!

Jm

Hey @Justin Laureltec - @Will Prowse in his 24v diagram has the BP directly to the positive connect at the inverter (just opposite of what I originally had)... is this incorrect: https://www.mobile-solarpower.com/2000-watt-24v-solar-system.html

Is the attached image better layout using the BP (this is based on Will's diagram)? The NEG shunt has also been updated correctly.

Thanks!

Jm

Johnmahon said:

Hey @Justin Laureltec - @Will Prowse in his 24v diagram has the BP directly to the positive connect at the inverter (just opposite of what I originally had)... is this incorrect: https://www.mobile-solarpower.com/2000-watt-24v-solar-system.html

Is the attached image better layout using the BP (this is based on Will's diagram)? The NEG shunt has also been updated correctly.

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Noooope, sorry... Will designed those diagrams before Victron really explicitly stated how you can and cannot use the devices, and I know he's updated most of his diagrams but it looks like that one got missed. This is not an allowed way to use the device.
The shunt is good though!

@Justin Laureltec - Sounds good - gonna just forego the BP Thanks man!

This is the one and only way to use a BP to disconnect an inverter... well, the one and only way that doesn't immediately void your warranty, I guess :-/

Thank you so much Justin. Exactly. I will write a note on that blueprint. Forgot to update that one! Trying to find thread about BP update and cannot find it -__- I will find it and sticky it so people know. Thanks again Justin.

Oh I did update that blueprint months ago! (pictured below) Ok cool. I will add the update to the picture as well so this confusion never occurs. Thanks everyone

@Justin Laureltec - How does this look?

Will Prowse said:

Thank you so much Justin. Exactly. I will write a note on that blueprint. Forgot to update that one! Trying to find thread about BP update and cannot find it -__- I will find it and sticky it so people know. Thanks again Justin.

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Man, I have looked all over for it as well, I haven't been able to find it. I was hoping to find it just so I could copy/paste a couple of discussion points and save myself some time typing out the explanations again
Whatever the case, I try to keep an eye out for any BP discussions so that I can pop in and point to the new manuals... thanks for keeping up on your end as well!

Johnmahon said:

@Justin Laureltec - How does this look?

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Theeeeere it is! Looks good to me
On another not quite unrelated point, have you -or are you planning to- spread some conductive grease on those busbars? Something like NO-OX-ID "A Special" or similar? They're pretty as hell but they won't stay that way without some kind of protection on them. Again, good chance you've already thought of it but I want to make sure...

Hey @Justin Laureltec - Happy New Year to you! Just wanted to let you know I got everything plugged into the batteries and everything seems to be working well. I still need to connect the solar panels. Gonna do that this weekend.

Take a look at the photo of the completed system

Thanks for all the help!

Jm

Hello @Justin Laureltec - just posted a video of the build and there are already negative comments - Ha... too funny. Just wanted to get your take. You can watch the video here and read the comment from Will Power - he says my battery cables should be the same length, which might be true - however, they are only about 6 inches different and everything is within 2 feet of each other - so how big of a deal is this...? I AM in the process of getting a fuse for the battery to the inverter (120A) - but what about grounding...? Can you shed some light there? I can ground it if needed. Is that done to the negative bus bar using a rod pounded into the ground outside connected by a solid copper wire? No problem if that is what I need to do

Thanks!

Jm

Johnmahon said:

Hello @Justin Laureltec - just posted a video of the build and there are already negative comments - Ha... too funny. Just wanted to get your take. You can watch the video here and read the comment from Will Power - he says my battery cables should be the same length, which might be true - however, they are only about 6 inches different and everything is within 2 feet of each other - so how big of a deal is this...? I AM in the process of getting a fuse for the battery to the inverter (120A) - but what about grounding...? Can you shed some light there? I can ground it if needed. Is that done to the negative bus bar using a rod pounded into the ground outside connected by a solid copper wire? No problem if that is what I need to do

Thanks!

Jm

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Dude, you could post a video of literally anything and there will be negative comments... some people just live for that. I'll go have a look though. Re the battery cables - technically speaking, all cables should be exactly the same length. Realistically speaking, a few inches difference here or there -particularly as long as your cables are of suitable gauge- won't make a lick of difference. A few milliOhms difference isn't gonna crash your system. Battery to inverter, yes you definitely need to be fused... I thought you had one already? Or maybe we just talked about one? Or maybe that was a different fuse... eh, hard to keep track, I have so many fusing conversations every day...
Grounding gets funky depending on your application; I mostly deal with mobile applications in which the inverter case ground gets tied to the vehicle chassis, but in permanent-mount installation at a residence, then sure, the ground should go to a ground rod (applicable regulations vary depending on actual usage intent).
We're a distributor only and don't do installs, so the simple reality is that the vast majority of our customers don't even use the case ground on their inverters and SCCs, but technically they definitely should.
I'll go have a look and see if I have any useful input

In that application the cables do not have to be of equal length. Makes no difference at all as it's a DC round-trip circuit.