[jkmann]

Thanks to everybody who's contributed so far. I'll get this worked out yet. Here's the latest version of my electrical system's supply side. Every time it feels like I have the electrical stuff ll figured out, somebody more knowledgeable makes a comment—on a topic that I'd never considered—and I'm back to the drawing board.

So come on, all you electrophiles. What am I doing wrong? @jkmann, I'm looking especially toward you, as you seem to know more about the safety side (fuses, breakers, ampacity, and so on) than most of the folk hanging out here, and far more than I. As before, I haven't yet worked out the details of the solar panels, so all of those specifics are still in flux.

Thanks, in advance, one more time.

View attachment 186940

Just a few things that stick out for me:
1) If you need AWG8 coming out of your solar combiners, that implies that AWG10 may not have the ampacity to handle your peak solar amperage. If that's the case, you should consider putting in-line MC4 fuses to protect the AWG10 wiring. Otherwise a short in your solar wiring could be quite nasty.
2) I don't see any circuit protection for the 120V circuits coming out of the Multiplus. Since overamperage on convenience outlets is the primary cause of breakers tripping, I think this is just an invitation to serious problems. It's quite easy to put in a couple of 20A AC breakers, even without a full blown AC distribution block. While I know some people do not have AC circuit protection against overamperage, I would not personally consider those to be safe installations.
3) You absolutely need to prevent both the shore power 120V input and the alternator inverter from being active at the same time. This is normally done with an automatic transfer switch that you hook both sources up to and it will just let one through to the Multiplus.

Other than those three items, I think there are some differences of design decisions that aren't important. I prefer fuses over breakers unless the switching function is needed, but either will protect a circuit. It's just that breakers have a higher failure rate than fuses.

Overall, looking good. It takes a little iteration to make everything fit well together. And, while it's nice to be asked for input, honestly I think others have more experience and knowledge than I do, and hopefully they will chime in as well.

 

[Jacek]

Let me know if you have any questions. Obviously there will be differences due to equipment choices.

The Blue Sea 5196 Terminal Fuse Block has only four posts, one common and three fused. I assume battery switch is connected to the common post, but it's not obvious to me how you are connecting the 400A ANL Fuse to the fuse block. Also, the fuse block is rated for 300A total. Any concern you might exceed that? Thank you for all your input!

 

[jkmann]

The Blue Sea 5196 Terminal Fuse Block has only four posts, one common and three fused. I assume battery switch is connected to the common post, but it's not obvious to me how you are connecting the 400A ANL Fuse to the fuse block. Also, the fuse block is rated for 300A total. Any concern you might exceed that? Thank you for all your input!

View attachment 186970

The actual wiring detail is that both the battery isolation switch and the BSS5196 are bolted directly to the input terminal of the ANL fuse holder. So the MRBF input busbar never has to carry more than 180A. I could have drawn that a bit more clearly.

As you can see the 3/8" stud on the ANL fuse holder can easily take the two connections. Theoretically the 180A from the solar and alternator power could be combined with 120A input from the Multiplus to create a maximum charging current of 300A, so even with all the sources going we would not exceed the capacity of the switch or the wiring. The 400A fuse limits the total power usage from all sources, which should be adequate, and is within the limits of the wiring.

 

[Smoobly]

1) If you need AWG8 coming out of your solar combiners, that implies that AWG10 may not have the ampacity to handle your peak solar amperage. If that's the case, you should consider putting in-line MC4 fuses to protect the AWG10 wiring. Otherwise a short in your solar wiring could be quite nasty.
2) I don't see any circuit protection for the 120V circuits coming out of the Multiplus. Since overamperage on convenience outlets is the primary cause of breakers tripping, I think this is just an invitation to serious problems. It's quite easy to put in a couple of 20A AC breakers, even without a full blown AC distribution block. While I know some people do not have AC circuit protection against overamperage, I would not personally consider those to be safe installations.
3) You absolutely need to prevent both the shore power 120V input and the alternator inverter from being active at the same time. This is normally done with an automatic transfer switch that you hook both sources up to and it will just let one through to the Multiplus.

Thanks much. As I expected, you found all the places I hadn't been looking.
1) Excellent. I haven't worked out the solar details mainly because I have yet to decide on which panels to buy. When I do, I will follow your advice.
2) Probably would have got there soon enough, but the AC-consumption side has not been in my thoughts. Will do these things.
3) A previous version of the diagram had an ATS. Can't remember why I took it out, or how I missed its absence.

Time to get busy.

 

[gregoryx]

Thanks to everybody who's contributed so far. I'll get this worked out yet. Here's the latest version of my electrical system's supply side. Every time it feels like I have the electrical stuff ll figured out, somebody more knowledgeable makes a comment—on a topic that I'd never considered—and I'm back to the drawing board.

So come on, all you electrophiles. What am I doing wrong? @jkmann, I'm looking especially toward you, as you seem to know more about the safety side (fuses, breakers, ampacity, and so on) than most of the folk hanging out here, and far more than I. As before, I haven't yet worked out the details of the solar panels, so all of those specifics are still in flux.

Thanks, in advance, one more time.

...

Go 200A on that breaker before the Multiplus. Assuming you're using the 3000/24/70, it'll go up to 6kW output, which is well over 200A; but 200A is an "available" unit and closer to what it'll see if getting pushed.

Also, recently learned that a GFCI doesn't work off the Giandel. Still looking into how to make it work - if possible - but Giandel's take is it's a non-issue.

Also, I'd do /something/ with the dual shore-power input other than just co-terminating them. Either an auto-transfer switch or a manual switch. My brother recently built nearly the same setup you have here but hadn't installed the ATS yet... you can see where this is going. Released the magic smoke from the Giandel.

Our setup is an actual 120VAC input that is either using the Giandel or shore - that's sufficient for the rare times we're on actual shore power. But if we added an external input, I'd install an ATS.

Ideally, a dual-breaker for the solar side of the MPPT - not just the "hot" leg. This has been reviewed and detailed out a few times on the forum. Battery side, just the hot is fine.

If your two 12VDC fuse panels are left/right side, I'd run two separate breakers.

 

[Smoobly]

Go 200A on that breaker before the Multiplus. Assuming you're using the 3000/24/70, it'll go up to 6kW output, which is well over 200A; but 200A is an "available" unit and closer to what it'll see if getting pushed.

Also, recently learned that a GFCI doesn't work off the Giandel. Still looking into how to make it work - if possible - but Giandel's take is it's a non-issue.

Also, I'd do /something/ with the dual shore-power input other than just co-terminating them. Either an auto-transfer switch or a manual switch. My brother recently built nearly the same setup you have here but hadn't installed the ATS yet... you can see where this is going. Released the magic smoke from the Giandel.

Our setup is an actual 120VAC input that is either using the Giandel or shore - that's sufficient for the rare times we're on actual shore power. But if we added an external input, I'd install an ATS.

Ideally, a dual-breaker for the solar side of the MPPT - not just the "hot" leg. This has been reviewed and detailed out a few times on the forum. Battery side, just the hot is fine.

If your two 12VDC fuse panels are left/right side, I'd run two separate breakers.

200A breaker into the MultiPlus? OK, will do.

No GFCI on the Giandel outlets? Good to know.

And yeah, as I mentioned to @jkmann, there used to be an ATS in there. It's back, now.

Breaker on both leads of the solar side of the panels, yes. As nearly everybody on the forum has mentioned. 😝

Thanks for all of those.