Wire Tube

[rob bc]

Hello all I am new to the form. I have a 2020 Reflection 300 RBTS it is pre wired for solar. What I am trying to find out is what is the largest gauge wire that can be fed through the tube Grand Design put in the trailer. I plan on installing 600 - 800 watts of solar. I know the wire they installed is 10ga. I emailed Grand Design and they forwarded my email to a dealer that could not answer my question. Thanks all for your help.
Rob

[howson]

Hello all I am new to the form. I have a 2020 Reflection 300 RBTS it is pre wired for solar. What I am trying to find out is what is the largest gauge wire that can be fed through the tube Grand Design put in the trailer. I plan on installing 600 - 800 watts of solar. I know the wire they installed is 10ga. I emailed Grand Design and they forwarded my email to a dealer that could not answer my question. Thanks all for your help.
Rob

I'm not sure anyone will know the definitive answer to that question, Rob. It's going to take some investigation on your part.

Have you determined which panels you'll be using and how they will be wired? Those decisions will have a significant impact on the wire size that's required from the roof to the controller to minimize loss in the system.

I'm not sure where I got the pic below, but it shows the relative size difference between wires. In my 1200W system I used 2ga.

If you have a pot of coffee brewed (it's a long thread) my install may help you understand how I decided to do what I did on my unit. It's documented in this thread: https://gdrvowners.com/forum/solar/1...n-2019-315rlts



Please take a moment and check out the Welcome Letter to New Members at https://gdrvowners.com/forum/main-fo...to-new-members too!

Howard

[TucsonJim]

Hello all I am new to the form. I have a 2020 Reflection 300 RBTS it is pre wired for solar. What I am trying to find out is what is the largest gauge wire that can be fed through the tube Grand Design put in the trailer. I plan on installing 600 - 800 watts of solar. I know the wire they installed is 10ga. I emailed Grand Design and they forwarded my email to a dealer that could not answer my question. Thanks all for your help.
Rob

Hi Rob.

I'm running 800 watts from the roof of my unit to the controller in the basement storage area. I ran two strings of four panels in series, then tied the output into a parallel combination which gives me an open circuit voltage of 85.6 volts DC, and a short circuit current of 11.4 amps.

On a 20 foot run, 10AWG will support 15 amps with a 3% voltage drop (maximum).

Jim

[rob bc]

Thanks for your help. I will look into it deeper. I would like to run a larger ga wire for the future in case I add more panels.

[TucsonJim]

Thanks for your help. I will look into it deeper. I would like to run a larger ga wire for the future in case I add more panels.

Got ya. 6 AWG will handle 40 amps at 20 feet with 3% loss. Here's the chart I use for DC current vs. wire size.

[Yoda]

Hello all I am new to the form. I have a 2020 Reflection 300 RBTS it is pre wired for solar. What I am trying to find out is what is the largest gauge wire that can be fed through the tube Grand Design put in the trailer. I plan on installing 600 - 800 watts of solar. I know the wire they installed is 10ga. I emailed Grand Design and they forwarded my email to a dealer that could not answer my question. Thanks all for your help.
Rob

I just measured my 8awg wires.Two 8 awg PV wires place side by side is 5/8" so hopefully you have at least a 3/4" tube. Where did GD place your access point. Can it be accessed from inside you unit

On my unit GD had not done the pre-wire yet. My dealer came down beside the black tank vent stack in the wall. Doing so gave him a straight shot to the pass through access beside the power distribution panel. He fit the wires beside the vent stack where it penetrated the floor, etc. However on your TT the vent stack is on the opposite end of your trailer and probably wont be much use.. I bought my PV wire from continuousresources.com

If your planing to use MC4 connectors be sure you use the 8awg ones if you using the 8 awg PV wire as the typical MC4 connectors out there are 10AWG

Hope this helps
Keith

[rob bc]

Thanks it is behind the front panel in pass thru easy to take panel off. Will do that when the weather in BC decides it wants to turn to spring. Thanks again.

[OffToHavasu]

I'm not sure if there's an actual tube in there, but here's the NEC Conduit fill table:

[howson]

OffToHavasu -- yet another topic I know nothing about, re: NEC Conduit and EMT Fill Tables, so I did a bit of reading.

See https://steeltubeinstitute.org/resources/post-4/

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NEC Conduit and EMT Fill Tables

Question: Please explain how to use the Tables in the National Electrical Code (NEC) to figure conduit fill. I have 3-12 AWG THWN, 4-10 AWG THWN, and 8-8 AWG THWN conductors. I plan to install them in EMT. What size EMT is required?
<deleted the rest--it's copyrighted! oops...>
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I'll put together a poll thread where a group of wires is given and the right answer for the conduit must be selected.

Howard

P.S. Just kidding about the poll...

[OffToHavasu]

You want me to do math?? It's Friday dude!

[TedS]

Here is a chart.

[rob bc]

Thanks everyone I think I have decided that I will stay with the factory 10ga to save a big headache. YouTube guy Jared Everything Rv's put 600 watts with 10ga on his reflection 5th wheel. Emailed him but one of those guys that doesn't answer question I guess just wants views to make money. I could easily put 800 watts on the roof but then back to wire size. Our weather is not nice right now so in a couple months I might start the project. Will keep everyone updated should I decide to run larger wire. Cheer's all

[Jlawles2]

Higher voltage with same wattage will equal less amperage. So you could get 800 watts by keeping the amperage the same but upping the voltage.