Solar pre-wire location

[AtomicNo13]

Originally Posted by rmkrum

Which is exactly why we didn't bother looking for the 'top end' of the dinky factory pre-wire when I installed solar on our AS. We used the nice heavy wire that came with the AM Solar kit. Bigger wire is better, period. And yes, I am an electrical engineering type person...


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EE type person?

[lewster]

Originally Posted by acstokes

Maybe someone can answer this question that's been puzzling me:

I'm no solar guru, but I've installed 2 systems of my own, one was 360 watts and the other 600 watts. The inverters were 1000 watts and the batteries used were 2-Lifeline 6v totaling 300ah. I would've added two more batteries if I had had more room in the front of my trailer near the inverter and DC breaker panel. I wired all panels in parallel and used #4 AWG for the run from my combiner to the MPPT controller. Once I used a Blue Sky controller and the second time a MidNite Solar controller...both American brands. I know some will say I should have used a Magnum controller, but I didn't want to pay the additional expense and I only needed a 1000 watt inverter.

I was puzzled by the fact that both the Blue Sky and MidNite Solar controllers would only accept wire size of up to 10 AWG for both input and output wires. After the expense of buying marine-grade #4 wire I had to downsize to #10 to connect to these controllers. Why aren't these controllers designed to accept up to at least #4 or #6 wire? Am I missing something here?

By the way, what size wire will Magnum controllers accept?

Thanks for your suggestions.

AC,

The missing link in your system is the use of spade connectors for larger cable sizes. We use 6AWG for the Blue Sky 2512iX-HV controllers and the appropriate spade connectors that allow the larger cabled to be inserted into the small screw-clamp connectors.

The larger 3024iL controllers will accept bare cable ends up to 2AWG with no additional connectors.

Can't address the Magnum solar controller, as I haven't used one yet.

[alano]

Yes, this is America. People are free to over-engineer their system. They're free to pay for unnecessary services. They're free to chase the last 2% to improve their efficiency!

For all the DIYers out there who like to save a few bucks and are interested in installing a 400 W system for less than $1500 I hope I've shed some light and offered another viewpoint. And yes, I have a BSEE.

[rodsterinfl]

Just looking over this discussion again tonight. Alano your details are helpful. I believe the only thing I find over calculated with your one mathematical example is the distance of 40' for the 10awg wire. That is a LONG wire run. In my puny system (compared to others) my total run prewire and added Renogy connection wire is 16.5'. Across the roof, down and over to the controller AND the cable to the batteries. That is what I was trying to say about resistance and other factors still being adequate with the prewire. The run is not long and the amperage is relatively low. A lot of it depends on what the goal is- to create a basic supplemental charging system or to create a mega solar array. Everyone is different. The prewire system should be able to handle up to about 200 watts. I have a hard time justifying a bunch of batteries and several panels for a 5.x something good charge time which is the case in most of the US states. Right now I can only view solar as a supplement to shore power and a generator. Perhaps it is my wallet but that's just me.

[rodsterinfl]

perfect. Thanks Gamma Dog. From your pic I can say that I ended up with the exact tank connector. I do not need the lever end though with my application.

[alano]

My example using a 35' length for the pre-wires was a very conservative estimate for my 30' classic since the pre-wiring starts near the battery box and terminates near the rear skylight. Of course you need to double this since there are two conductors when calculating the resistance. Every other AS model probably results in a shorter length.

Also In my example I was able to install a 400 W system using the pre-wiring where the voltage loss due to the pre-wiring was less than 2%. This example requires the use of an MPPT controller and a series/parallel arrangement for the four panels. No reason to limit such a system to 200 W.

[rodsterinfl]

well there ya go. Two percent is nothing. Yes, I see what you mean about the length.

[acstokes]

The missing link in your system is the use of spade connectors for larger cable sizes. We use 6AWG for the Blue Sky 2512iX-HV controllers and the appropriate spade connectors that allow the larger cabled to be inserted into the small screw-clamp connectors.

Lewster,
Thank you for this advice. I had not considered using spade connectors to maintain wire size to/from the controller. I have been using terminal blocks before and after the controller to accommodate change in wire diameter.

[111]

OK, I'm looking for recommendations on this topic for my 23D 2015 model.
I have a "GO Power" 200 watt system that I would like to add. The monitor is designed to be wired directly to the main power cables and doesn't appear to use the Cat 5 control wires. My factory solar wires run from the BUS to the rear fantastic fan.

1. Do I drill through the fantastic fan trim to access the roof?
2. Does the factory wire routing go by the false wall in the bathroom sink area to mount the panel? If not, where do I mount the monitor. Not much room next to the BUS.
3. I'm planning on using VHB tape and Sikaflex 221 to attach the flex panels to the roof.

[111]

http://www.airforums.com/attachments...4/img_1854.jpg

[alano]

I'm not familiar with the FC 23D configuration but maybe I can steer you in the right direction.

1. Do you have an interior LED light next to the fantastic fan? In my installation I was able to remove the light (3 screws) and grab the pre-wiring in the ceiling. I was also able to simply drill a hole in the roof from below using the opening from the interior light. If your setup is different, perhaps you could remove the fan trim and see if you can locate the wires. If you can, I would drill a hole from above the roof, several inches away from the fantastic fan, to feed the solar pre-wires through. You'll add a combiner box above the hole where you can tie together the solar panels to the pre-wiring.

2. Not sure where the factory wiring goes inside the trailer, but if the wires terminate near the BUS, you'll want to try and place your solar charger close to the BUS, since you'll be trying to keep the losses to a minimum. In my installation the Blue Sky charger was mounted next to the BUS and an optional remote was located at the other end of the CAT5 cable. In your case you don't have an optional remote so you'll need to try and find a suitable location near the BUS for your controller.

3. VHB tape and Sikaflex 221 should work fine.

[rodsterinfl]

I know that there is controversy here on wire size; however, I want to refer to this chart. The prewire should be able to handle up to around 200 watts. I contacted Renogy about the wire they sell when I did my meager system they told me for my need it was fine. Since then they have created a page for determining wire gauge for distance and system size. The page is a calculator so it will match any job. My system on roof is 150 watts (10 amps or so) with a run from panel to battery of about 19 feet (16.5 feet to controller) at most with 10 AWG.

https://www.renogy-store.com/Wiring-...ors-s/1822.htm

[111]

Thank you for your responses. The bus is under the dinette seat at the front of the trailer. I could mount it there but your feet may be hitting the panels buttons. I was hoping to intercept the factory wires at the bathroom sink and mount the panel in the false wall there.

Having a hard time tracing the wires route. May have to just start disassembling.

[Al and Missy]

Has anyone located the green and yellow pre-wire at the roof in a 2000-era Safari? My manual says it is "under the front dome light". There is only a small hole where the light wires come out and sticking a finger up in there as far as I can I cannot feel any other wires. I'm considering getting a nibbler and opening up the area inside the mounting screws, but if the wire is near the fan, that won't do me any good.

I want to connect the red and black to the yellow and green behind the control panel and use that for fan power. The fan is currently spliced into the light which makes the light switch at the door dual function. I'd rather have it just control the light.

I sorta shot myself in the foot when fixing leaks at the fantastic fan and TV antenna base by injecting foam. I stiffened up the roof nicely, but sure makes access more difficult.

Thanks,

Al

[alano]

Originally Posted by rodsterinfl

I know that there is controversy here on wire size; however, I want to refer to this chart. The prewire should be able to handle up to around 200 watts. I contacted Renogy about the wire they sell when I did my meager system they told me for my need it was fine. Since then they have created a page for determining wire gauge for distance and system size. The page is a calculator so it will match any job. My system on roof is 150 watts (10 amps or so) with a run from panel to battery of about 19 feet (16.5 feet to controller) at most with 10 AWG.

https://www.renogy-store.com/Wiring-...ors-s/1822.htm

Attachment 251100

Strictly speaking, the prewire can handle 10 A, but don't confuse this with the panel wattage. You can stack panels in a series/parallel arrangement. In my series/parallel configuration you can have 400 W (4 x 100 W panels) and still keep the current to approximately 10 A (10.6 A in my case).

[Al and Missy]

Originally Posted by Al and Missy

Has anyone located the green and yellow pre-wire at the roof in a 2000-era Safari? My manual says it is "under the front dome light". There is only a small hole where the light wires come out and sticking a finger up in there as far as I can I cannot feel any other wires. I'm considering getting a nibbler and opening up the area inside the mounting screws, but if the wire is near the fan, that won't do me any good.

....
Al

I bought an air nibbler. Cool tool!!! But it didnt help. I opened up the ceiling under the light and felt all the way to the fan but no luck. I should have looked at the wiring diagram. It shows the yellow and green coming out at the same location as the fridge wires, so they must be in the refrigerator compartment, not at the ceiling light, which is a different harness.

Al

[Burnside Bob]

Al & Missy:

In my 2009 FC the pre-wire was not run into the ceiling--only to the bottom of the refer compartment.

You can see the yellow and green wires taped to end of plastic conduit in this photo. These wires end where the battery bus bars are located--in my unit under the queen bed. At the bus bars they are labeled as the solar pre-wire wires.

[Al and Missy]

Thanks Bob,
I was hoping the text description of the prewire was correct so i could use the wires to power the fan instead of tapping off the light. Oh well, i guess i'm stuck with it the way it is.

Al

[Burnside Bob]

Originally Posted by rodsterinfl

I know that there is controversy here on wire size; however, I want to refer to this chart. The prewire should be able to handle up to around 200 watts.

I would like to add solar, so I've been following this discussion. I have been wondering if 200W of solar would be enough so the 10 gauge seems marginal to sketchy.

Since those #10 wires are there, its a shame not to use them. Why not combine them--two strands of #10 tied together are the same ampacity and resistance/foot as one strand of #7 and then run one strand of #6 to complete the solar circuit. Alternately, run two strands of #8 and wire one #8 and one #10 together to get the equivalent ampacity and resistance/foot of a circuit made entirely from #6?

Doing either would result in a circuit that could handle more watts of solar at lower cost with less voltage drop.

[rodsterinfl]

My pre wire was in the fridge compartment as well. The manual listed it and I found it.