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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: AC7880 on October 25, 2016, 08:54:37 pm

Title: Solar factory prewiring run?
Post by: AC7880 on October 25, 2016, 08:54:37 pm
For my continuing education, on 2003 to 2005 Foretravel U320 with factory solar prewiring, does anyone know how the wires are run, and gauge of the wiring?  If the factory wire gauge is insufficient for modern high watt systems (say 600 watts), is it attached internally, or possible to hook new heavier gauge to existing wiring, and "pull" the heavier gauge?  This question is for coaches with the 3 8Ds in the middle of the coach.

Anyone been there done that?
Title: Re: Solar factory prewiring run?
Post by: DavidS on October 25, 2016, 09:43:14 pm
I didnt know they had any wires pre ran.. where would we find them?
Title: Re: Solar factory prewiring run?
Post by: AC7880 on October 25, 2016, 09:51:53 pm
My understanding is that it was a factory option.  So only some coaches will have it in place. 


I didnt know they had any wires pre ran.. where would we find them?

Title: Re: Solar factory prewiring run?
Post by: toyman on October 26, 2016, 06:38:38 pm
Mine has a breaker for solar, but I saw no wires for it. This isn't the easiest coach to pull wire in.
Title: Re: Solar factory prewiring run?
Post by: MisterEd on September 17, 2019, 02:00:14 am
Our coach has the factory solar stub-out. It must be factory, since the red and black 10AWG wires are integral with the harness from the pilot overhead storage to the front of the curbside floor wiring chase.

From the roof down:
Roof entry location. (pic 1)
Hole with wires going into a roof rafter. (Pic 2)
Wires/loom entering interior through hole in bottom of roadside roof rafter, just forward of TF slide locking cylinder. (Pic 3)
Going to the front OH console above pilots seat. (The loom between the aluminum extrusion and steel truss over the slide opening. (Pic 4)
Down the vertical wire chase behind pilots seat, and through the floor. (Pic 5)
Out of the floor above LF wheel, and into the cross member, heading to curbside*. (Pic 6)
Out of cross member and into interior curbside chase below copilot cup holder*. (Pic 7)
From there, the wires go through the curbside floor chase and enter the basement in bay 2, just behind the first intermediate bulkhead and above the inverter. (No pic) The wires had been cut there.
*Note: Factory wiring is loom my finger is on. Others are not factory.

Greg

 

Title: Re: Solar factory prewiring run?
Post by: Jack Lewis on September 17, 2019, 02:52:28 am
Maximum current capacity for 10 gauge wire is 30 amps according to the national electrical code, NEC, so this limits your solar capacity.  You may want to pull new wire anyway. I had no problem pulling the solar wire.  I would recommend using using 4, or 6 gauge wire, depending on your system requirements and future needs.  I make a recommendation to go up a size from your current needs, to make room for expansion.  I bought all my wire, junction box, breakers, solar panel hold downs from AM Solar, and they will help size your system.

It took me only two years to want to go from 560 watts to 1200 watts.  That was after going 14 years with only 150 watts.  So much depends on your needs.  No use wasting $$$ with too large a system, or too small a system, that you will upgrade in the future. 

Solar Cable Gauge Calculator (https://www.renogy.com/calculators)

RV Solar Panel Kits & Camping Solar Panels, Batteries & Chargers: AM (https://amsolar.com)
Title: Re: Solar factory prewiring run?
Post by: jcus on September 17, 2019, 11:35:58 am
30 amps at 120 volts is 3600 watts, so if you run series or series parallel to raise your voltage, no problem. I am running one 960 watt string at 120 volts, this is only 8 amps on 10 gauge.
Title: Re: Solar factory prewiring run?
Post by: Pierce & Gaylie Stewart on September 17, 2019, 12:13:50 pm
The practical maximum is 4 panels and around 1300 watts on a 36 foot 102" coach. The 40s may, depending on roof layout, take one more panel. The panels are so cheap now that you only have to add $150 maximum for an additional panel.

I just bought a couple of $25 Siemens 12V panels to make into two chargers for my tractor and car I don't drive much. This is in our home town and you can see they have hundreds of panels from new to a couple of years old. It's estimated 500,000 panels are thrown away each year. Too bad as they loose very little efficiency even at 10 years old. New panels are producing more watts per panels so the older ones are becoming obsolete.

Example in Grass Valley: Selling solar panels for charity - general for sale - by owner (https://goldcountry.craigslist.org/for/d/cedar-ridge-selling-solar-panels-for/6955687598.html) These are the same size commercial panes as the ones we have on our U300 but our panels are 10 years old now and 285 watts so I could replace ours for $500 and get about 200 watts more.

Pierce
Title: Re: Solar factory prewiring run?
Post by: folivier on September 17, 2019, 02:09:35 pm
Do all or most FT's have this factory wiring?
Title: Re: Solar factory prewiring run?
Post by: jcus on September 17, 2019, 02:35:13 pm
Do all or most FT's have this factory wiring?
None of the four I have had did. My 2003 has a self resetting breaker labeled "solar", but no wires running to it, so assume the wiring  was a factory option. I had to run two duplex 10 gauge marine wires down behind fridge to battery bay.
Title: Re: Solar factory prewiring run?
Post by: Jack Lewis on September 17, 2019, 03:07:14 pm
30 amps at 120 volts is 3600 watts, so if you run series or series parallel to raise your voltage, no problem. I am running one 960 watt string at 120 volts, this is only 8 amps on 10 gauge.

I like your comment, however I am having trouble thinking of equipment in todays market that I would buy and mount on my rv, giving 3,600 watts, let alone just to save having to rewire from the roof.

I did a similar system to yours, yielding 1187 watts on the roof with 4 older design 60 cell panels.

The math was as follows.  Max power of 335 watt panels 34.1 (max power volt, VMPP) x 2 = 68.2 V x 9.83 (max power current, MPP) = 770 watts.  LG 280 31.9 volt x 2 = 63.8 v x 8.78 = 560 watts.  In parallel 63.8 volts (lower of two parallel voltages) x 18.61 amps (combined amps) = 1187.31 watts from my roof system.  My 100 amp, 150 volt solar controller is rated for 1400 watts in a 12 Volt system, thus I ended up with the above 1187 watt system.

Solar Battery Charging (https://www.foreforums.com/index.php?topic=37423.25)
Title: Re: Solar factory prewiring run?
Post by: jcus on September 17, 2019, 03:58:18 pm
I like your comment, however I am having trouble thinking of equipment in todays market that I would buy and mount on my rv, giving 3,600 watts, let alone just to save having to rewire from the roof.

I did a similar system to yours, yielding 1187 watts on the roof with 4 older design 60 cell panels.

The math was as follows.  Max power of 335 watt panels 34.1 (max power volt, VMPP) x 2 = 68.2 V x 9.83 (max power current, MPP) = 770 watts.  LG 280 31.9 volt x 2 = 63.8 v x 8.78 = 560 watts.  In parallel 63.8 volts (lower of two parallel voltages) x 18.61 amps (combined amps) = 1187.31 watts from my roof system.  My 100 amp, 150 volt solar controller is rated for 1400 watts in a 12 Volt system, thus I ended up with the above 1187 watt system.

Solar Battery Charging (https://www.foreforums.com/index.php?topic=37423.25)
I run two strings each with its own solar controller and 10 gauge feed. First is three 72 cell panels with a VOC of 40 volts in series. So 960 watts at around 8 amps at 120 volts. The second string is three 160 watt panels  in series at about 22 VOC per panel. So about 7 amps at 66 volts. All in theory though, never see it that actual amount. Agree 3600 watts is not very likely, but did read about one guy that had  2400 watts, but think that was a 5th wheel with basement air. Some of the new solar controllers are good for 250 volts now, so possible to run 5 big panels in series.
Victron Energy SmartSolar MPPT 250/100-Tr Solar Charge Controller w/ B (https://www.continuousresources.com/products/victron-energy-smartsolar-mppt-250-100-tr-charge-controller-w-bluetooth?variant=9370682228772&utm_medium=cpc&utm_source=goog)
Title: Re: Solar factory prewiring run?
Post by: Jack Lewis on September 17, 2019, 04:53:01 pm
Not really, although this is called a 100 amp 250 volt controller,  in a 12 volt system it is only rated for 1450 watts, the same as my 100 amp, 150 volt controller.

"Victron Energy SmartSolar MPPT 250/100-Tr Solar Charge Controller Specifications:

Battery Voltage: 12V/24V/48V Auto Select (software tool needed for 36V)
Rated Charging Current:  100A
Maximum PV Short Circuit Current:  70A
Maximum PV Open Circuit Voltage:  250V
Nominal PV Power (12V System):  1450W"

I run two strings each with its own solar controller and 10 gauge feed. First is three 72 cell panels with a VOC of 40 volts in series. So 960 watts at around 8 amps at 120 volts. The second string is three 160 watt panels  in series at about 22 VOC per panel. So about 7 amps at 66 volts. All in theory though, never see it that actual amount. Agree 3600 watts is not very likely, but did read about one guy that had  2400 watts, but think that was a 5th wheel with basement air. Some of the new solar controllers are good for 250 volts now, so possible to run 5 big panels in series.
Victron Energy SmartSolar MPPT 250/100-Tr Solar Charge Controller w/ B (https://www.continuousresources.com/products/victron-energy-smartsolar-mppt-250-100-tr-charge-controller-w-bluetooth?variant=9370682228772&utm_medium=cpc&utm_source=goog)
Title: Re: Solar factory prewiring run?
Post by: jcus on September 17, 2019, 05:32:26 pm
On the 250 volt unit, you could run five 280 watt panels or five 300 watt panels, not very likely to develop the full 1500 watts. Victron did tell me though, that its solar controllers will limit amperage to protect itself.
But I believe it's more for people who because of space limitations, run smaller panels. Ten 100 watt panels in series, would be 1000 watts at around 200 volts.
Or for the increasing popular 48 volt systems using a leaf or tesla battery, where it can handle 5800 watts of solar.
Title: Re: Solar factory prewiring run?
Post by: AC7880 on September 18, 2019, 12:11:31 am
Do all or most FT's have this factory wiring?
I believe most do not.