I tried researching the answer but get confused between ac and dc systems. I want to make sure I do this right so I’m going to just ask for my specific installation. I’m running dc from panels with tigo rsd to Eg4 18kpv using the mc4 wire since it’s a short run, straight down from roof to inverter. I have the racking grounded to each then into solar deck box. Now should I run a ground in the conduit from the solar deck box to the inverter along with the 2 mc4 wires?
Grounding question
- Thread starter Bricktop
- Start date
BentleyJ
Solar Wizard
Yes, Not only to the inverter but all the way to the ground bus on the breaker panel that is being powered by the EG4. This panel should be tied into the house ground and trace back to the ground rod.
MidwestBest
Redneck Engineer
im likely wrong but wouldnt it be better to run the gorund wire down and add a ground rod for the panels? or is that also ok just overkill?
hwy17
Anti-Solar Enthusiast
It's not ok and it's incorrect. You have to ground back to the house grounding system.
Sometimes you can ground back to the house ground AND add a ground rod, but most people agree it either doesn't help or is worse.
Not an expert, but this is falling out of favor.
The best way to handle this is to get your array ground to your house ground/ground rod, and have no additional ground rod by the array.
Brett V
Mad Scientist
Ground wire should not be in the conduit but can run beside it. All grounds go to a common point. If you choose to add a ground rod, it must also tie to the main house ground.
hwy17
Anti-Solar Enthusiast
I don't think that's correct. Is it?
BentleyJ
Solar Wizard
The ground wire can and should be run in the same conduit as the conductors.
They can be in the same conduit unless something has changed in the past 3-4 months.
Brett V
Mad Scientist
I've used #6 solid copper and run it outside the conduit since pulling solid wire is impossible.
Brett V
Mad Scientist
Grounding Overview for DIY Solar: 5 Helpful Tips
Proper solar panel grounding is key for passing your solar panel installation. Learn more about grounding requirements and mistakes to avoid.
blog.gogreensolar.com
It doesn't have to be solid wire or that large if it's inside the conduit. (provided you aren't running some hugely high amp PV array).
My current project is adding on to an existing system I had installed by a company. I checked and they have a green wire ran in conduit with pv wires. So what size wire do I need? It is 4.4kw additional panels in series at 25amps
The Solar Wire Size Calculator
plug in the numbers. Your ground wire can just match your PV conductor sizing. I think you can downsize, I just don't know those rules off the top of my head so you'll need to look into that further. I just ran the same size so I didn't have to do any more math and it would fit in my conduit easily.
Zwy
Emperor Of Solar
No, only one grounding point, the electrical system ground.
Zwy
Emperor Of Solar
It only needs to be #6 if exposed.
Inside a conduit if the current carrying conductors are 10AWG, then you can run 10AWG ground wire. You can go to 12AWG or 14AWG it depends on current on the conductors. I just run 10AWG, makes it easier but if conduit fill won't be met with the 10AWG, then I would step down if it meets conduit fill. Check out the chart here for ground wire according to current of conductors.
Zwy
Emperor Of Solar
25A would need 10AWG as 12AWG is only 20A.
EG4_Jared
Online Support for EG4 Electronics
We recommend against connecting the PV ground to the PE Bus in the 18kPV, as we've observed it causing electromagnetic interference when grounded directly in the inverter. Instead, the PV ground should be traced back to the ground rod.
MidwestBest
Redneck Engineer
well i may need to change my setup because my array is grounded with its own rod at the moment but its 100ft away from my house.. so thats why i did it that way.
Brett V
Mad Scientist
Thanks for the correction. My system has a ground mount so it's probably better I used the #6 solid since it might be subjective to say if it's protected or not. My experience is with radio towers where we use oversize copper on everything for lightning protection and it just followed through in my head.
