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My new construction home DIY solar build thread (EG4 18Kpv) Texas 🇺🇲

AustinMaddox

New Member
Joined
Feb 6, 2024
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Location
Texas
Hi! New member, first post 👋
We're nearing completion on our new home so I thought I'd start documenting the build (with photos, of course) as I go along.

The story begins,... apparently I love things that use electricity because I had so many circuits (15kW HVAC, pool heater/chiller, 3 HP well pump, aerobic septic, EV charger, two refrigerators, one freezer, shop/man cave, welder, air compressor, mini-split, etc.) that the electricians suggested that I install a 320 amp meter base feeding two 200 amp panels from the grid. Okay, cool.

Then, being an engineer and quite left-brained, I started doing the calculations and spreadsheets and whatnot on how much I could expect my monthly electric bill to be. I crunched the numbers and checked the price per watt from the local power company and was shocked 😳. I needed a new plan. Started looking into solar. Watched way too many YouTube videos, and ended up here, lurking on the forums for months.

Long story short, I drove to Sulphur Springs and picked up an EG4 18Kpv inverter from Signature Solar last week. Just got it mounted. Let the games begin!
 
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Hi! New member, first post 👋
We're nearing completion on our new home so I thought I'd start documenting the build (with photos, of course) as I go along.

The story begins,... apparently I love things that use electricity because I had so many circuits (15kW HVAC, pool heater/chiller, 3 HP well pump, aerobic septic, EV charger, two refrigerators, one freezer, shop/man cave, welder, air compressor, mini-split, etc.) that the electricians suggested that I install a 320v meter base feeding two 200 amp panels from the grid. Okay, cool.

Then, being an engineer and quite left-brained, I started doing the calculations and spreadsheets and whatnot on how much I could expect my monthly electric bill to be. I crunched the numbers and checked the price per watt from the local power company and was shocked 😳. I needed a new plan. Started looking into solar. Watched way too many YouTube videos, and ended up here, lurking on the forums for months.

Long story short, I drove to Sulphur Springs and picked up an EG4 18Kpv inverter from Signature Solar last week. Just got it mounted. Let the games begin!
Welcome!
Good choice so far. It’s had a lot of beta testing at this point so it’s ready for prime time.
Only one 18Kpv? 🥴
 
I can’t exactly get my head around the 320v two panel thing, but I’m not an electrician. However, we’ve got some real electricians here that will chime in, in due time.
Edit, yeah I see you corrected v to amps 👍
 
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Sorry, I meant 320 amp, not volts.
Probably went with two 200 amp panels for cost and/or availability I’m guessing.
I think you’re going to like EG4 line of products. Probably one of the best for DIY friendly plus code compliance at a reasonable price. And,no I don’t own one.
 
Hi! New member, first post 👋
We're nearing completion on our new home so I thought I'd start documenting the build (with photos, of course) as I go along.

The story begins,... apparently I love things that use electricity because I had so many circuits (15kW HVAC, pool heater/chiller, 3 HP well pump, aerobic septic, EV charger, two refrigerators, one freezer, shop/man cave, welder, air compressor, mini-split, etc.) that the electricians suggested that I install a 320 amp meter base feeding two 200 amp panels from the grid. Okay, cool.

Then, being an engineer and quite left-brained, I started doing the calculations and spreadsheets and whatnot on how much I could expect my monthly electric bill to be. I crunched the numbers and checked the price per watt from the local power company and was shocked 😳. I needed a new plan. Started looking into solar. Watched way too many YouTube videos, and ended up here, lurking on the forums for months.

Long story short, I drove to Sulphur Springs and picked up an EG4 18Kpv inverter from Signature Solar last week. Just got it mounted. Let the games begin!
Exciting!! Please don't hesitate to reach out to us with any questions or concerns!
 
sweet, note: lots of pics brings in viewers and suggestions

and thanks for the show and tell entry, love looking at others' projects

I wish the 18kpv was available when I was choosing the XW Pro, I would have gone with the 18kpv instead
would have been cheaper
 
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As you can see, I've planned for a second inverter to be added at a future date. At the present time, the way we're going to wire it is one service line from the grid to the 18kpv inverter (left) and then to Load Center #1 (left). The other service line will go directly to Load Center #2 (right) since there is no inverter there yet. At a later time, I can move the grid service line to go through inverter #2. I hope that makes sense. Any suggestions?

Also, we're doing spray foam insulation so I am a little worried that the top of the conduits will get covered or make them much less accessible from the attic. I'll probably just do some bat insulation at the top of the conduits to make it easier to pull lines through the conduit at a later date.
 

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As you can see, I've planned for a second inverter to be added at a future date. At the present time, the way we're going to wire it is one service line from the grid to the 18kpv inverter (left) and then to Load Center #1 (left). The other service line will go directly to Load Center #2 (right) since there is no inverter there yet. At a later time, I can move the grid service line to go through inverter #2. I hope that makes sense. Any suggestions?

yeah, great idea. I built my system for growth over time, just takes proper planning. good work

Also, we're doing spray foam insulation so I am a little worried that the top of the conduits will get covered or make them much less accessible from the attic. I'll probably just do some bat insulation at the top of the conduits to make it easier to pull lines through the conduit at a later date.

yeah leave good access yes, might lose a little heat/cooling but gives you flexibility
watch conduit fill levels on those Romex runs
 
This’ll probably be a fun thread. I would suggest that any PV containing conduit, junction box or breaker/surge arrestor box within the building structure be within approved metal.
The gray conduit is fine for AC.
 
Noted, Skypower. Thanks for the advice. I think I could swap out the two conduits I was planning on using for PV wires for metal conduits instead of PVC. The rest is already metal (gutters, connectors) so I should be good there.
 
At a later time, I can move the grid service line to go through inverter #2. I hope that makes sense. Any suggestions?
Looks perfect to me.
Also, we're doing spray foam insulation so I am a little worried that the top of the conduits will get covered or make them much less accessible from the attic. I'll probably just do some bat insulation at the top of the conduits to make it easier to pull lines through the conduit at a later date.
Remove or cover EVERYTHING, darn shit gets all over.
Fiberglass bats would be best but remember, you will need to fire stop that area....mine are inside the wall. Looks like you will sheetrock to the conduit and fill around them. The mud guys will love you :ROFLMAO:
 
Looks good, sounds like you were not going to parallel the 18Kpv. Unless I missed something. There was a thread about running a 3 HP pump on a 18Kpv. I tried to find it but failed. In your research was the 18Kpv able to handle the 3 HP pump? Off grid (grid down) thanks
 
I wasn't planning on paralleling the 18Kpv, unless there is some advantage to doing so that I'm not aware of.

As far as the 3 HP well pump, the way I understand it:
1. If it can't power it, the 18Kpv will get the required power from the grid (bypass). Is that not correct?
2. As a last resort, I can move the 3 HP pump circuit to Load Center #2 which is directly connected to the grid. No inverter.
 
1. If it can't power it, the 18Kpv will get the required power from the grid (bypass). Is that not correct? Yes, as long as the grid is available. But when the power goes out, and there is no PV. The 18Kpv can supply Max. Continuous Output Current 50A (12,000 watts and Without PV: 13.5kW for 10 min. So the 3HP pump and other loads might overwhelm the 18Kpv causing it to shut down. Do you know the surge watts of your 3 HP Pump? I found this on the web, but it might not apply to your pump.

One of the concerns I was think, was if the pump was able to trip the 18Kpv from an overload. And the 18Kpv kept resetting every 300 seconds that would put a lot of stress on the pump.
 

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I wasn't planning on paralleling the 18Kpv, unless there is some advantage to doing so that I'm not aware of.

You sould measure the in-rush current. I have a fan for an heat air blower and I measured a 8 Amp
when running but the in-Rush current of 56 Amp, so 7x. ( I used an UEi DL429B Digital Multimeter)

If you want to be able to run your pump when there is a power outage,
I would stronly recommend having both EG4 connected,
and if you want to run on battery, to add a SoftStart device.
 
100%. DC must go in metal conduit.
What is the basis for this code requirement?

Seems arbitrary to me. If PVC is good enough to protect AC wiring (that could be higher voltage and power than DC), why isn't it good enough to protect PV DC wiring?

And even odder, PVC is okay outside the building for PV DC wiring.

Mike C.
 
What is the basis for this code requirement?

Seems arbitrary to me. If PVC is good enough to protect AC wiring (that could be higher voltage and power than DC), why isn't it good enough to protect PV DC wiring?

And even odder, PVC is okay outside the building for PV DC wiring.

Mike C.
Arcing that can cause fires?
 
And if there was a breach, want it Arc against the metal conduit causing the AFCI switch in the inverter to shut it down?
 
Yes, measured for PowerPro wall mount batteries. I don't know if I'll add them ($$$), but I'd sure like to!
Definitely is the right idea to plan ahead. The PowerPros really look slick, lots of people on here seem to have them.

You must live in an area with a stable grid. Where I am in the US, I've learned to live with just putting all my electronic devices on UPS's. I must have 5 or 6 in the house. Got really tired of flickering power during mild thunderstorms after years of dealing with it.

I dream of the day that I can just have a UPS on my PC and the rest of the house covered by a whole-home solar/battery system!
 
What is the basis for this code requirement?

Seems arbitrary to me. If PVC is good enough to protect AC wiring (that could be higher voltage and power than DC), why isn't it good enough to protect PV DC wiring?

And even odder, PVC is okay outside the building for PV DC wiring.

Mike C.
I can't explain how the NEC decided it, but you have to do it for a code compliant install.
 
Arcing that can cause fires?
Metal conduit makes that more likely, not less, since it provides conductive material everywhere.

Also, metal conduit means cutting metal and metal shavings. That's the last thing I want to mix with power wires.

I suspect this has to do with metal conduit suppliers or trade unions and really has no basis in safety.

Mike C.
 
Metal conduit makes that more likely, not less, since it provides conductive material everywhere.

Also, metal conduit means cutting metal and metal shavings. That's the last thing I want to mix with power wires.

I suspect this has to do with metal conduit suppliers or trade unions and really has no basis in safety.

Mike C.
I had a discussion with @timselectric on this. The idea is around arcing on the DC conductors inside the tube. I guess hopefully the gap will widen or a breaker will trip, and steel will not catch fire in the mean time. Of course a big enough arc will chew thru steel as easily as plastic, but might give you a bit more time. I think it's a little esoteric, but it's a reason. If you accidentally create an arc inside the conduit steel would be better than PVC, which would likely catch fire. High voltage DC is not as forgiving as AC.
 
If you accidentally create an arc inside the conduit steel would be better than PVC
Last year I had installed about 45 feet of PVC in my crawl space for solar PV (250V), until I started reading this forum.
I gladly ripped it all out and replaced it with EMT.

And, I have a GFPD, so if the + shorts to the conduit, it will trip.
 
If you accidentally create an arc inside the conduit steel would be better than PVC, which would likely catch fire.
So why is PVC okay outside the building, say on the roof, if that is the reason? Fire there is okay somehow?

Mike C.
 
Spray foam insulation is in. Drywall is underway! I covered my precious 18Kpv with a garbage bag to prevent sheetrock mud and spray getting into the vents in the top.
 

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