22kW EG4 Rooftop PV project (June 2025)

[kc130up]

San-Tan has some 400's for ~ $4k. . .

View attachment 300378

I saw those and they are on the list. A pallet makes them ~.29 PPW which is pretty low.

Question > Some pallets are 26, 36, and some are seemingly random amounts. If I need 50 panels, does that still count as a pallet even though it isn't a multiple of 26 or 36?

 

[chill633]

I saw those and they are on the list. A pallet makes them ~.29 PPW which is pretty low.

Question > Some pallets are 26, 36, and some are seemingly random amounts. If I need 50 panels, does that still count as a pallet even though it isn't a multiple of 26 or 36?

All panels will ship palletized -- on a pallet. But the full pallets come that way in containers from the manufacturer. If you change it, it doesn't count as a full pallet.

If you need 50 and the packet is advertised at 26, you either buy 52 or they have to break the manufacturer packing on the second pallet to remove two and repack. If it were that close, of suggest buying the full 52 and having a couple spares.

For 36 & 50, that's a pallet and 14 purchased individually. That isn't going to be the same PPW on the +14.

 

[ksmithaz1]

San Tan might do pallet+ for the pallet price.

 

[kc130up]

I am ready to place the first equipment order, which will be the Gridboss and Flexboss21.

I should have did this last week when the holiday sales were going on! Maybe they'll have father's day deals too...

It seems current connected is cheaper than signature solar. How is this possible? Isn't SS owned by EG4?

 

[chill633]

I am ready to place the first equipment order, which will be the Gridboss and Flexboss21.

I should have did this last week when the holiday sales were going on! Maybe they'll have father's day deals too...

It seems current connected is cheaper than signature solar. How is this possible? Isn't SS owned by EG4?

EG4 sells thru multiple resellers. Vendors very rarely sell direct to the public at prices lower than they do their dealer network. If they played favorites, undercutting their channel, they'd lose resellers and lose business.

The dealers compete on more than just price.

 

[kc130up]

Ordered the FB21 & GB today! Moving right along.

I am finalizing wire needed from the GB > FB. Its a 50' trenched run using in 1-1/4" PVC using #2 stranded copper.

I had hoped to use aluminum to reduce cost, but I saw in another thread and confirmed in the GB manual that is says "No AL".

My electrician says the ground wire has to be the same size as L1&L2 and solid copper. I read people on the forum that are using stranded for the ground.

I can't seem to find solid #2 solid copper. Where are people getting their wire from?

 

[chill633]

Your electrician is incorrect. NEC 2020 for reference. The ground running from the FB21 to the GB should be #6.

250.122 Size of Equipment Grounding Conductors.
(A) General.
Copper, aluminum, or copper-clad aluminum equipment grounding conductors of the wire type shall not be smaller than shown in Table 250.122. The equipment grounding conductor shall not be required to be larger than the circuit conductors supplying the equipment. If a cable tray, a raceway, or a cable armor or sheath is used as the equipment grounding conductor, as provided in 250.118 and 250.134(1), it shall comply with 250.4(A)(5) or (B)(4).

Equipment grounding conductors shall be permitted to be sectioned within a multiconductor cable, provided the combined circular mil area complies with Table 250.122.

As far as "must be solid" goes, if you're running it across in conduit, it MUST be stranded at that size.

310.3 Conductors
(C) Stranded Conductors.
Where installed in raceways, conductors 8 AWG and larger shall be stranded, unless specifically permitted or required elsewhere in this Code to be solid.

Even not in a raceway, we have this:

250.118 Types of Equipment Grounding Conductors.
The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combination of the following:
(1) A copper, aluminum, or copper-clad aluminum conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape.

If the electrician insists, ask him to point out the code reference because you're seeing otherwise and don't want issues with the inspection.

EDIT: I'm an idiot. The connection from the FB21 to the GB isn't 200A, it is 90A. That means #8 AWG copper, not #6. The thicker (6) is acceptable, the #8 will be cheaper and easier to work with.

 

[kc130up]

So I can run #2 stranded copper from the FB > GB for L1 / L2 / Neutral and run #8 copper as the ground?

 

[chill633]

So I can run #2 stranded copper from the FB > GB for L1 / L2 / Neutral and run #8 copper as the ground?

According to Table 250.122, yes. That's what I ran, but haven't had my inspection, yet. If your electrician is saying otherwise, ask for a code reference.

My GEC -- the wire that goes to the buried ground rods from the first point of disconnect -- is solid #4. The idea of needing solid #2 for a normal EGC is insane.

 

[kc130up]

Thanks! I'll ask for the code reference.

I believe the theory is if something goes wrong and the ground has to "ground" some voltage / current, the ground must be able to handle the same voltage / current of the wires it is supposed to be grounding.

Otherwise the ground wire melts and now there is no ground.

 

[chill633]

Thanks! I'll ask for the code reference.

I believe the theory is if something goes wrong and the ground has to "ground" some voltage / current, the ground must be able to handle the same voltage / current of the wires it is supposed to be grounding.

Otherwise the ground wire melts and now there is no ground.

Code says otherwise. Just phrase it to the electrician as if you're learning and are confused by what you see in the codebook versus what he is telling you. Make him work for it

 

[kc130up]

I TXT'd him and he didnt respond. I guess he's doing some crap like spending time with his family on the weekend...haha.

So I asked my AI and was surprised that Mike Holt was one of its first references.



AI said #6 is all that is needed...

 

[kc130up]

Electrician said solid ground isn't needed AND a #6 is all I need for the 2/0 cable run.

 

[kc130up]

No place local stocks the copper 2/0 service cable. Is there a trusted online resource that someone can point me to?

Shipping update > The FB21 & GB are supposed to be here Friday.

The plan is to have the electrician install the GB first, then I can trench and connect the FB21 > GB using the 10 panels I already have to start with.

 

[chill633]

No place local stocks the copper 2/0 service cable. Is there a trusted online resource that someone can point me to?

Shipping update > The FB21 & GB are supposed to be here Friday.

The plan is to have the electrician install the GB first, then I can trench and connect the FB21 > GB using the 10 panels I already have to start with.

Nassau on Amazon.

 

[empowered]

Another question is how to get wires to the other arrays on the other side(s) of the roof?

View attachment 298603

The plan is to use Pegasus bond boxes under each array to connect and switch from PV wire to THHN. Since PV wire can't lay on the roof, i ASSUME we need something like EMT between the arrays.

Since you cant run PV wire inside EMT, it seems like a bunch of switching between THHN and PV to wire everything up.

Tell me there is a better way!?

why cant you run PV wire inside EMT?

 

[kc130up]

You CAN (i'm told.) The concern is heat. Since PV is double shielded, it heats up in EMT in the sun. THWN is better for EMT in hot conditions (i'm told).

Not sure it makes a big difference, but THHN seems cheaper. My main reason is the outside cable diameter of THHN is smaller thus smaller (cheaper) conduit can be used with THHN.

 

[kc130up]

Nassau on Amazon.

That is $512/20' which is ~$26/ft...

That seems more expensive than I can get from the local supply houses even accounting for shipping and some "$40 cut fee".

I can get it locally for $17/ft. I need 13' so that is $221 + $40 = $261.

Is my calculator lying to me :D

 

[chill633]

That is $512/20 which is $30/ft...

That seems more expensive than I can get from the local supply houses even accounting for shipping and some "$40 cut fee".

I can get it locally for $17/ft. I need 13' so that is $221 + $40 = $261.

Is my calculator lying to me :D

Local supply houses are best, if they have it in stock. I'll buy from City Electric first, then check a couple other locals if they're out. Nassau is last resort, but still acceptable.

 

[chill633]

You CAN (i'm told.) The concern is heat. Since PV is double shielded, it heats up in EMT in the sun. THWN is better for EMT in hot conditions (i'm told).

Not sure it makes a big difference, but THHN seems cheaper. My main reason is the outside cable diameter of THHN is smaller thus smaller (cheaper) conduit can be used with THHN.

PV wire is a silicone sleeve, which is sticky and a major pain for pulling. Lots of cable lube needed for that. THHN is slicker and easier to pull. However, I have a couple 100' rolls of PV wire and I'll take the pulling pain just to not have a splice in my line.

 

[kc130up]

I considered the line losses from splicing. We'll be using DK4N's for splices, so losses should be as low as possible.

If i already had the PV wired i'd consider just bigger conduit, but since i have to buy both, THHN wins.

 

[kc130up]

I was about to pull the trigger on order the Tigo's. I thought i had made my final decision...

If I go with the Tigo 2F's, vs optimization, i save ~$1200. I don't have enough shading to justify spending $1200 more for optimization but I would like to know how much power each panel is providing.

Having individual panel power data is worth something. Not sure if its worth another $1200.

Is there a way to get individual panel data without Tigo?

 

[455dan]

No place local stocks the copper 2/0 service cable. Is there a trusted online resource that someone can point me to?

Shipping update > The FB21 & GB are supposed to be here Friday.

The plan is to have the electrician install the GB first, then I can trench and connect the FB21 > GB using the 10 panels I already have to start with.

NNC- Nassau National Cable. for Aluminum, Copper not so much for some reason

 

[chill633]

I was about to pull the trigger on order the Tigo's. I thought i had made my final decision...

If I go with the Tigo 2F's, vs optimization, i save ~$1200. I don't have enough shading to justify spending $1200 more for optimization but I would like to know how much power each panel is providing.

Having individual panel power data is worth something. Not sure if its worth another $1200.

Is there a way to get individual panel data without Tigo?

Yes. NEP PVG-2-L 1-2 Panel Level Rapid Shutdown, but you'll need the NEP PVG-O-D | BDG-256 Gateway | PVG-C-D1 to configure and monitor. Check Signature Solar, as the RSD units are real cheap. In addition to RSD they have panel-level statistics and the whole setup can be run either thru NEP's cloud gateway, or local monitoring.

 

[kc130up]

You da man!