Whole home system

[EZPZ]

Hi all,

So finally have everything working the way I am happy with. Purchased system late last year and got it up and running in December. Built the ground mounts with 6x6 treated wood, 2x6 treated wood and superstrut.

System:
1x EG4 18kpv inverter
42x 400w bifacial panels in 3 arrays of 14 panels each
1x EG4 WP 48v 100ah battery
Grid tied with sell back

Lots of concrete - 15000 lbs
Lots of pv cable - arrays are over 400ft away from house so lots of trenching and conduit.

Did all the array ground mounts and all the dc stuff myself and had an electrician come out and just do the ac stuff. Then had the utility company come out and check things and swap out my meter and activate the sell back feature.

I dont want to be offgrid. The grid is my backup hence the small battery. Also batteries are too expensive for my liking and budget.
I wanted to have no change to how or when I run appliances etc and didn’t want to have an “essential” circuit. Everything in the house in my opinion is essential . I wanted everything on the house side to not change and for me not to have to change how my completely random day of using power goes.

The objective was to not have a lifestyle change at all but to reduce or eliminate my utility bill as much as possible. My march utility bill is trending to be $0.

Naturally it was lots of hard work and sweat and several issues that popped up, but doing it yourself was so rewarding and gives you a good understanding of the system. And yes at some point I will add more battery - hint hint @Will Prowse - thanks for the website and all the videos. Research before jumping into this project is invaluable, so keep up the sharing of info.

 

[blrmaker]

Nicely done. Thank you for posting. Did your electrician provide all of the AC side of the equipment?

 

[chilly2]

Nice work! Glad you have a utility that allows great setups like this. How are your panels attached to the superstrut? Are there holes in the back of their frames or is there a clamp that I'm just not seeing?

 

[mciholas]

I notice the grid and load ground wires are not tied to the PE bus bar but to ring terminals bolted to the enclosure. I think they should be terminated to the PE bus bar. I would not depend on the enclosure to carry earth connections.



Mike C.

 

[EZPZ]

I sourced all the ac side stuff as well. The electrician just connected and put together the ac side. What a mission finding 200a units though. And we won’t even talk about how much they cost.

The panels are attached to the superstruts with strut channel nuts that fit in the superstrut - see picture.


The earth is also attached to the pe busbar - see cable between the battery cables. I thought that as well…but that’s what the electrician did…

 

[chilly2]

I sourced all the ac side stuff as well. The electrician just connected and put together the ac side. What a mission finding 200a units though. And we won’t even talk about how much they cost.

The panels are attached to the superstruts with strut channel nuts that fit in the superstrut - see picture.

Thanks for the reply! Do you have a link to those strut channel nuts, and what sort of clamp do you have holding the panel to them? A bolt and washer?

 

[mciholas]

Do you have a link to those strut channel nuts, and what sort of clamp do you have holding the panel to them? A bolt and washer?

Search for "unistrut nuts".

Very versatile channel system.

Mike C.

 

[EZPZ]

Yes bolts and washers on the panel into the superstrut nuts

I got them from Amazon - https://www.amazon.com/gp/product/B0BHSQBCXV/
Just choose the right size and thread.

The superstruts are connected to the 6x6 poles in the ground and also to 6x6 wood blocks between the 2x6’s using lag bolts. The 6x6 poles are 12 ft long and go into the ground about 4 feet deep and then I poured concrete to fill each hole (at least 5x 80lb bags of concrete per pole)

 

[timselectric]

I notice the grid and load ground wires are not tied to the PE bus bar but to ring terminals bolted to the enclosure. I think they should be terminated to the PE bus bar. I would not depend on the enclosure to carry earth connections.

View attachment 199370

Mike C.

Agreed, those are not good connections.
Bolted separately to painted surfaces. When there's a provided ground bar.

Also don't see any EGC for the PV array.

Safety, is the most important part of any electrical installation.
It's a very nice looking system.
Just a little less safe than it should be.

 

[EZPZ]

I can fix both those suggestions. Thank you. Always willing to learn and make things better.

Can I just run a connection from each of the superstruts to a ground rod? Or more specifically from 1 superstrut per panel row to a ground rod? As opposed to connecting each panel and then to a ground rod.

 

[timselectric]

I can fix both those suggestions. Thank you. Always willing to learn and make things better.

Can I just run a connection from each of the superstruts to a ground rod? Or more specifically from 1 superstrut per panel row to a ground rod? As opposed to connecting each panel and then to a ground rod.

No ground rod at the array. That would provide zero safety and actually make things worse in other ways.
An EGC is supposed to be ran with the PV circuit conductors, back to the existing grounding system.
In your case, the ground bar in the 18kpv is the simplest option. Once it's actually connected to the grounding system. (The other correction discussed)

If your mounting hardware is approved for grounding.
Then yes, connecting to one point of each array will be sufficient.

 

[EZPZ]

No ground rod at the array. That would provide zero safety and actually make things worse in other ways.
An EGC is supposed to be ran with the PV circuit conductors, back to the existing grounding system.
In your case, the ground bar in the 18kpv is the simplest option. Once it's actually connected to the grounding system. (The other correction discussed)

If your mounting hardware is approved for grounding.
Then yes, connecting to one point of each array will be sufficient.

So a cable connecting the panels from each array back to the inverter ground that is over 400ft away in the same conduit? That’s not going to happen. The pv wires are in conduit that is already buried and I don’t see me digging that up again. What would be the next best option then?

 

[timselectric]

So a cable connecting the panels from each array back to the inverter ground that is over 400ft away in the same conduit? That’s not going to happen. The pv wires are in conduit that is already buried and I don’t see me digging that up again. What would be the next best option then?

There isn't a next best option.
And why would you dig it up? The purpose of conduit is to have a raceway for conductors. They can be replaced or reconfigured at anytime.
Just re-pull the run with the correct wiring.

400' is a long run. I would expect a few pull boxes.

 

[EZPZ]

I could use the wires from string #2 from array #1 as they are not been used and they already are in the conduit. So could I then use one of those pv wires? Could I just do a wire from array 2 and array 3 and connect it to array 1 and then join those 3 wires to said wire at array 1 and then at the inverter connect said wire to the pe block?

 

[timselectric]

I could use the wires from string #2 from array #1 as they are not been used and they already are in the conduit. So could I then use one of those pv wires? Could I just do a wire from array 2 and array 3 and connect it to array 1 and then join those 3 wires to said wire at array 1 and then at the inverter connect said wire to the pe block?

Yes
I would re identify it as green. At every location it can be seen or accessed.

 

[1201]

Hey congrats on your system and doing it yourself, saving thousands.

That single battery looks lonely

 

[registered-bum]

Great looking system - and thank you for the pics, diagrams and details!

Q1: Did you run all of the PV wires in the same conduit?

Q2: Is there a limit to how many current carrying wires you can stuff into conduit (per code)?

 

[Sennen]

Q2: Is there a limit to how many current carrying wires you can stuff into conduit (per code)?

Yes (Link)

 

[EZPZ]

Great looking system - and thank you for the pics, diagrams and details!

Q1: Did you run all of the PV wires in the same conduit?

Q2: Is there a limit to how many current carrying wires you can stuff into conduit (per code)?

Q1. Yes I did.

 

[EZPZ]

Hey congrats on your system and doing it yourself, saving thousands.

That single battery looks lonely

Thanks - yes it’s lonely. Hoping someone like Will with tons of batteries just sitting around will send some my way. I am a farmer so don’t know how to get that lonely one to reproduce…