Conduit diameter for 3 strings
- Thread starter Nick34
- Start date
Hi thanks . Are the numbers corresponding to 10AWG the number of strand wire?
hwy17
Anti-Solar Enthusiast
1" is surely good enough. Pretty sure 7x10awg fits in 3/4 officially.
For the PVC Conduit Table, the wire conductor heading is THWN and THHN, they are both stranded wires, but I dont know the strand wire count to make the 10 awg size, maybe there is another table for this.
Thanks Does Galvanized Steel Electrical Conduit For EMT works for outdoor ? also what junction box is suitable thanks
fatjay
Solar Wizard
40% fill rate, I would absolutley use pvc. I did this and had 3 sets of wires in half inch. I think the limit was 10 wires.
Edit, 9 wires in half inch according to chatgpt and project gemeni. 6 wires if the conduit is metal.
Edit, 9 wires in half inch according to chatgpt and project gemeni. 6 wires if the conduit is metal.
Q-Dog
¯\_(ツ)_/¯
If you are running DC anywhere inside a house you need to use metal conduit. PVC is good for outdoors.
Thanks what type of 10AWG wire did you use ?40% fill rate, I would absolutley use pvc. I did this and had 3 sets of wires in half inch. I think the limit was 10 wires.
Edit, 9 wires in half inch according to chatgpt and project gemeni. 6 wires if the conduit is metal.
Hi can you explain the wires in the junction box? are there 3 strings?40% fill rate, I would absolutley use pvc. I did this and had 3 sets of wires in half inch. I think the limit was 10 wires.
Edit, 9 wires in half inch according to chatgpt and project gemeni. 6 wires if the conduit is metal.
fatjay
Solar Wizard
Yes, that is my joiner box where 3 strings come in to join one set of wires to go back to one inverter. I have 6 inverters, 3 of which are powered by solar.
I have 39 panels and I will have 3 strings (13 panels per string ) is THHN 10 AWG wire good for conduit us? Also is your junction box in the picture closed to the inverter or on the roof? thanks
fatjay
Solar Wizard
3 strings should be ~24a, so 10awg would be suitable. The junction box is in the roof, i have 3 sets of 3 strings coming in. It's regular 10awg THHN from home depot, in 500' spools.
Thanks I am also looking to get the home depot 10 AWG wire. Is this parallel wiring?
fatjay
Solar Wizard
THHN is not outdoor rated and must be in conduit. You need actual PV wire.
I used this:
You also need a proper combiner box with fuses and shutoff's. Each string is ~8a, but I would go with the wire rating for the fuses. There are many on amazon, but i cannot comment on them because I build my own.
I used this:
You also need a proper combiner box with fuses and shutoff's. Each string is ~8a, but I would go with the wire rating for the fuses. There are many on amazon, but i cannot comment on them because I build my own.
Q-Dog
¯\_(ツ)_/¯
Midnite has boxes that can be configured for just about any setup you can design.
Soladeck is a nice product for aflash in roof mount jbox. It gives direct access to the attic and looks like a standard roof vent. You can order them with fuses, or pass through, or nothing internally but a ground bus. - I used heyco 2-hole strain reliefs for each string, then transitioned from rpvu90 to t90(your thhn)using weidmuller w6u6 terminal blocks on the provided din rail.
Ez solar sells a rack Mount jbox.
In a pinch you can use a PVC box and wirenuts. Ipex sells ( 277006) a nice unit you can get with a backplate if you want to make your own solution.
Last edited:
ricardocello
Watching and Learning
The Voc for each string is over 711V according to the OP in another thread, and total Isc is 39A.
Post in thread '3 phase grid-tied solar system questions'
https://diysolarforum.com/threads/3-phase-grid-tied-solar-system-questions.92258/post-1282845
Post in thread '3 phase grid-tied solar system questions'
https://diysolarforum.com/threads/3-phase-grid-tied-solar-system-questions.92258/post-1282845
ricardocello
Watching and Learning
No, 600V
Actually I googled, some brands of THHN are rated 1000V
Not the stuff at home depot or lowes
I see PV wire goes up to 2 kV
ricardocello
Watching and Learning
That wire is RHW-2 and is rated for 1000V, good.
The jacket is rubber, which means running it through conduit in long lengths will require Superman pulling and the Hulk pushing.
Use lots of lube.
Unless you are directly burying it, then its great.
Don’t forget to run a ground wire (EGC).
The jacket is rubber, which means running it through conduit in long lengths will require Superman pulling and the Hulk pushing.
Use lots of lube.
Unless you are directly burying it, then its great.
Don’t forget to run a ground wire (EGC).
I also have a red home depot 10 AWG wire -will tis work or I should return it
Cerrowire 500 ft. 10 Gauge Red Stranded Copper THHN Wire 112-3873J - The Home Depot
Cerrowire Gauge Stranded THHN Single-Conductor Electrical Wire is perfect for use in commercial and industrial applications.
www.homedepot.com
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