How big can you go?

[TRW]

I may not have a accurate grasp of this thread, but I will offer a few thoughts. First, if you have a big system, you will use much of it while the sun is shining, it might be an alternative to have a back up generator for times when a reasonable size battery bank can keep up.

 

[time2roll]

Trying to figure out the max size for a 48 volt system. What do you consider the practical limit?
Parallel charge controllers and inverters are a must. Largest CC I have seen is 120 amps.

I would say 200 amps is the practical easy limit but 400 amps is pushing it. Depends on the battery as well. Those terminals can only handle so much current.
Any ideas? What's the largest off grid system you have seen that's DIY?

My house has 200 amp service so 48 Kw would be my practical limit. Keep adding battery until I could run 10 days with no solar would be about max or my practical battery limit. My needs are far less so this would not actually happen.

 

[Short_Shot]

This is my best guess as to a technical reason:

Electrical treeing - Wikipedia

en.wikipedia.org

Purdy, ain't it?

Now that you mention it...You might be on to something. Ish.

Not that specifically though because that's typically done with a couple thousand volts AC.

I think it has something to do with limiting the ability for it to arc, in that AC sort of 'extinguishes' itself. I vaguely remember that now from a class a few years ago.

iirc that's why both DC and AC specific breakers and switches/disconnects exist.

 

[Hedges]

Arc in breakers and switches, for sure. Was trying think of a way the issue could exist for a busbar.
For insulators, there is creepage and clearance, together with pollution degree. Also tracking. And dendrites.

The polarized DC breakers have a design where permanent magnet or electromagnet pulls the arc into chutes to extinguish it.

I'm curious how this one can be non-polarized and 50k AIC. Same figure on OEM's site, so not a typo.

Product - MidNite Solar

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