Need a main panel, pv wire, ecg (array) recommendation

[Nan_wpg]

OK. You can get this I think in DIN form, and put it in a junction box with the SPD you mentioned. Or you can use breakers.

I don’t think straight terminals would be my jam, you’ll have to like disconnect at an MC4 before working in this box.

Many options. Just looking for input as I piece my “balance of system” out.

 

[zanydroid]

OK. I wonder what people will think of one solid isolator (that is definitely switch rated), and the other one being potentially flakier just to save money and size.

 

[timselectric]

Stranded #19 PV is needed for any connection point that needs flexibility for service. Like plugging into the panels. There is a table in NEC saying it must be thus.

The question was about the conductors in the conduit.

 

[zanydroid]

The question was about the conductors in the conduit.

Ok then it doesn’t matter, but why even use PV? More expensive and harder to pull. Need to transition from 19 strand anyway so just go to THHN.

Because unless I’m missing something this is a 600V system so you don’t need the extra voltage capability from pulling PV

 

[timselectric]

im thinking cheap plastic box with busbars.

That's fine. I used standard wire nuts.

May even put an SPD at that location.

That's OK. Just keep in mind that it will only be protecting the solar panels.
It's more important to have one near the SCC location.

as for burial depth for conduit (not talking code, but safe) is the depth to protect from other people digging, or is it to dissipate current if there’s a short?

im asking because I’m trenching in the middle of no where. There’s no “call before you dig”. Shallower is easier. To bring a trencher out is a bit of an ordeal.

Just to protect against physical damage.

 

[timselectric]

Ok then it doesn’t matter, but why even use PV? More expensive and harder to pull. Need to transition from 19 strand anyway so just go to THHN.

Because unless I’m missing something this is a 600V system so you don’t need the extra voltage capability from pulling PV

Thhn is what I would use.
I only use PV wire, exposed at the array.

 

[Nan_wpg]

OK. I wonder what people will think of one solid isolator (that is definitely switch rated), and the other one being potentially flakier just to save money and size.

I don’t understand

 

[Nan_wpg]

Ok then it doesn’t matter, but why even use PV? More expensive and harder to pull. Need to transition from 19 strand anyway so just go to THHN.

Because unless I’m missing something this is a 600V system so you don’t need the extra voltage capability from pulling PV

I’m instaling wire for a system at a cabin that’s not mine (wife’s family). Was looking for easy, and cheap. Pv is easier and faster, but more money. Thwn- 2 is cheaper (even with conduit) but a bit more work.

 

[zanydroid]

I don’t understand

Do you need two switch rated isolator for oh shit emergency disconnection under load? Or is one fine and you can save $50 and put something cheaper at the other end as a convenience disconnect m

 

[Nan_wpg]

That's fine. I used standard wire nuts.

That's OK. Just keep in mind that it will only be protecting the solar panels.
It's more important to have one near the SCC location.

Just to protect against physical damage.

Funny, I never thought to use marrettes, i have lots of them kicking around my basement.

was already instaling an SPD at the CC. I figured if I go with a junction box (as opposed to 100% pv) than I can easily add an SPD. It,can’t hurt.

 

[Nan_wpg]

Do you need two switch rated isolator for oh shit emergency disconnection under load? Or is one fine and you can save $50 and put something cheaper at the other end as a convenience disconnect m

Are we talking about the IMO that you linked? I “think” I only need one (was going to put at the CC), but if I can use it also at the pv end (will also help transition) then why not? But marrettes would be even cheaper in a junction box.

again, just thinking about things. What would you do?

 

[zanydroid]

Are we talking about the IMO that you linked? I “think” I only need one (was going to put at the CC), but if I can use it also at the pv end (will also help transition) then why not? But marrettes would be even cheaper in a junction box.

again, just thinking about things. What would you do?

Yes, the IMO. Hmm. Well having an obvious to access disconnect, that is idiot proof, in more places seems theoretically good if you need one right in an emergency, or after a long debugging session and you are getting desperate and stupid. But if there is time and sanity available I think one is sufficient.

There are some people here that aren’t into wire nuts for DC. Things like SolaDeck come with DIN terminals not a bag of wirenuts if you buy their deluxe kit. But they’re also a platinum plated type of junction box.

 

[Nan_wpg]

Yes, the IMO. Hmm. Well having an obvious to access disconnect, that is idiot proof, in more places seems theoretically good if you need one right in an emergency, or after a long debugging session and you are getting desperate and stupid. But if there is time and sanity available I think one is sufficient.

There are some people here that aren’t into wire nuts for DC. Things like SolaDeck come with DIN terminals not a bag of wirenuts if you buy their deluxe kit. But they’re also a platinum plated type of junction box.

My initial thought was pv wire from array to,CC. IMO switch at that point. Then I,thought conduit and,then-2, but how,to transition.

junction box,is,cheapest. What’s wrong with wire nuts for,DC?

 

[zanydroid]

junction box,is,cheapest. What’s wrong with wire nuts for,DC?

Higher consequence of arcing in DC vs AC.

Should be a few threads theorycrafting about that, I don't know if anyone has data.

 

[timselectric]

DC arcing is a problem. But it only happens when you break the circuit. A properly made connection (no matter how it is done) , should never break the circuit.
People who have a concern about wire nuts. Definitely should not use them. (Or do anything electrical)

 

[Nan_wpg]

Yes, to all.

That's fine.

No
Direct contact between earth and a bare conductor.
In places where it's not a good thing.
Not an issue at the GEC (Grounding Electrode Conductor).
But it's best to avoid with any EGC (Equipment Grounding Conductor). Especially when outdoors and over distance.

Tim, I will have lots of 6g twist left over from the GEC. can I use it for the EGC for my system? (NOT the array EGC). This would be inverter, and CC. My ac side will be grounded with the copper in the 12/2 wire.

there‘ll be no contact with earth. And I can tape the bare wire. I’d hate to see the extra wire go to waste.

you recommended UF-B wire for direct burial. This is solid wire (unless it’s available in stranded?) and Victron’s manuals say to use finely stranded wire. Would this be more so for the CC to battery cable, and not so much the PV to CC cable?

I always thought AC = solid, and DC = stranded. I’m back and forth between conduit and direct burial. Direct burial would be cheapest (especially with uf-b) and way easier.

 

[timselectric]

Tim, I will have lots of 6g twist left over from the GEC. can I use it for the EGC for my system? (NOT the array EGC). This would be inverter, and CC.

Not sure what you mean.

My ac side will be grounded with the copper in the 12/2 wire.

This is your EGC for your system.

you recommended UF-B wire for direct burial. This is solid wire (unless it’s available in stranded?) and Victron’s manuals say to use finely stranded wire. Would this be more so for the CC to battery cable, and not so much the PV to CC cable?

Run it from the array to your PV disconnect, near your system. Then, you can run stranded from the disconnect to the SCC.

I always thought AC = solid, and DC = stranded.

They are interchangeable.
Stranded is better for vibration situations.

I’m back and forth between conduit and direct burial. Direct burial would be cheapest (especially with uf-b) and way easier.

I prefer conduit. But the choice is yours.
Whichever works best for you.

 

[Nan_wpg]

Not sure what you mean.

This is your EGC for your system.

Run it from the array to your PV disconnect, near your system. Then, you can run stranded from the disconnect to the SCC.

They are interchangeable.
Stranded is better for vibration situations.

I prefer conduit. But the choice is yours.
Whichever works best for you.

I am using 6g twist bare copper for my grounding rods, up to the grounding bus bar.

my inverter will ground to the busbar via 12g wire that’s used for the ac system.

can I use the bare 6g twist as my EGC for my charge controller to the ground bus bar? I’ll have plenty left over, and it’s the right size too. (Power cable is 6g)

will I be able to connect mc4 to uf-b? Or would run PV >junction box, transition to uf-b > disconnect > transition to stranded > charge control?

 

[timselectric]

can I use the bare 6g twist as my EGC for my charge controller to the ground bus bar? I’ll have plenty left over, and it’s the right size too. (Power cable is 6g)

Yes that's fine. You can always over size.
You can never go smaller than the minimum.

will I be able to connect mc4 to uf-b?

No

Or would run PV >junction box, transition to uf-b > disconnect > transition to stranded > charge control?

This

 

[Nan_wpg]

Yes that's fine. You can always over size.
You can never go smaller than the minimum.

No

This

What about a nice 10g “generator” extention cord to connect the array to the charge controller?

Plug in when we’re there, unplug when we’re gone. Super easy, and portable when we hopefully get our own cabin (or just rent one with power)