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Solar controler placement question

I'm beginning to start the installation of my solar/inverter system.
I located my batteries now I need to locate the best area for the Charge controller (Victron).
I'm running 4 - 300watt- panels. They will be wired parallel. All components other than panels are Victron

My choices are.
Run the wires from the panels to a kitchen cabinet directly below the panels ( about a 4' run) and install the Solar Controller and on/off switch with breakers to that location. I would have the controller and breakers/switch inside the RV and the wire run from the controller to the monitoring controls (Victron Color) would be easier.

Install the controller in the battery bay (about a 16' run from the panels). Install the on/off switch and breakers inside the battery bay or install the breakers and panel on/off switch inside the rv and then run the wires to the battery bay for hook up to the controller.

I lean towards the inside mounting location but would opt for the BEST location. I have  a plug in Controller monitor( installs on the face of the solar controller) so I could see solar info from either mounting location.

1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: Solar controler placement question

Reply #1 –
Loss per foot is very high for 12 volt, better to put charge controller as close as possible to batteries. Series/parallel on panels would be a better bet.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Solar controler placement question

Reply #2 –
If your charge controller is MPPT, use a series/parallel or straight series configuration of panels to reduce voltage drop and allow you to use thinner gauge wire.  I ran the solar wires down the refrigerator vent and placed an on/off knife switch on the floor of the refrigerator compartment behind the refrigerator.  From there, the wires run to the controller in the equipment bay, mounted right under the inverter-charger, just a bulkhead away from the house batteries.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Solar controler placement question

Reply #3 –
Most 300 watt panels have an open circuit voltage of about 40 volts. Running 4 in series will give you 160 volts, above the 150 volt limit on controllers that Victron makes. 2 in series will give 80 volts, so you can use 10 or 12 gauge from each 2 panel string to feed controller. Running the wires as in previous post is probably the best way but will vary by year and model.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Solar controler placement question

Reply #4 –
I ran 2 controller's

4ea 300 watt panels 2 in series 2 in parallel

Roof down the fridge vent across the basement to the area of the batteries and went from there. .all victron and I like it

1200 w Solar

Re: Solar controler placement question

Reply #5 –
What is the advantage of running series/ parallel vs all parallel?

I chose all parallel wiring based on research that showed greater voltage loss if some panels are partially shaded and the ability to add future panels that are different from the others installed.

Nothing installed yet so changes to my "plan" are easy to make now.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: Solar controler placement question

Reply #6 –
Quote from: Lon and Cheryl –
What is the advantage of running series/ parallel vs all parallel?

I chose all parallel wiring based on research that showed greater voltage loss if some panels are partially shaded and the ability to add future panels that are different from the others installed.

Nothing installed yet so changes to my "plan" are easy to make now.
Parallel wiring for all panels means a lot more wire and a lot bigger wire. Running two strings of two panels in series allows you to position the coach so at least two of the panels are not in the shade. If dry camping, I try to position so entire coach is in the sun, so never worried about the small loss of power for parallel vs series,  which really only comes into play when the sun is at a extreme angle, and maybe an ac shadows a panel, by that time your solar input is pretty low anyway. Your call, but for me, less wires, and less connectors means far less possibilities of a bad connection causing resistance, and this far outways the extra couple of k/w hours I might lose.
Adding more panels are not a problem, if the same voltage, they can also be run in series/parallel or series, then you do not have to drop down any more wires at all. Eg: If running 2 panels in series at combined 80 volts, you can series one more 40 volt panel and get 120 volts, still safe for your controller [if a 150 volt controller] Of course you would have to add the same number and voltage panels to each string.
Panel wattage is not a big factor, panel voltage is.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Solar controler placement question

Reply #7 –
I placed my controller and cutoff switches at the base of the bed, plenty of room to mount and ran the wiring from the panels down the refrigerator vent, under the closets, and in the channel between the drawers and the foot of the bed (was able to run 4 gauge through the channel for positive and negative). Ran the wire to the batteries through the bottom, and only have a 6' run to minimize loss. I overbuilt using 4 gauge for future upgrades and safety.
AKA Chuck
1993 U280 40' WTB, Build 4345, CUM 8.3 "Falcor", 2010 Honda CRV TOAD (Spock), 970W solar on roof
Full-Time traveler between Quartzsite AZ, Longview WA, Ellendale ND, and Lake City SD
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Re: Solar controler placement question

Reply #8 –
Quote from: Roger & Susan in Home2 –
"Parallel wiring for all panels means a lot more wire and a lot bigger wire. "

Wire size is a function of length, amps and volts.  For a 300 watt panel at 24 volts for 30' run with 1% voltage loss or less #8 wire will work fine. Two in series for 48 volts lets you use #10 wire and you still need a cable between the two panels.  Not really a "lot bigger wire".  Maybe some less total length for all of panels.  All of this wire is a small fraction of the total cost.  So do what makes the most sense for your installation and expected use. 

All of my wires run under other panels or along side something.  They go into the refrig space and down into the water manifold bay where everything was easy to install and maintain.  I didn't want any wire joints, boxes or any extra stuff on the roof.

He is running 4 300 watt panels.  probably 46 volt open circuit. If all in parallel he will have to either run 4 twin lead cables all the way to a junction box then the charge controller, or use a junction box on the roof, in that case, he would have to run heavy  and expensive 2/0 cable down to the charge controller.
Much easier to put two panels in series and run two, easy to run, 10 gauge cables down to the charge controler. IMHO
I am currently running 3 320 watt panels in series and never get over 117 volts on my 150 volt charge controller and I just had to plug one panel into another than two 10 gauge wires down to the basement .

 


Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.