2 PV Sources 1 SCC?

[LanduytG]

I have a Victron 150/70 mppt scc for the main panels, 4 255 watt Canadian Solar panels mounting on the roof of my 5th wheel and it comes with a plug so you can connect a portable solar panel. Since the 4 roof mounted panels are going to be wired 2s2p into the Victron and they are series connected I assume the single ground unit will need its own SCC? The ground unit is the same panel but only 1 of them.

Greg

 

[Craig]

yes if your second array produces half the voltage you would need another SCC. You could also ad another panel or run the first 4 in parallel then you could use the 5th panel with your current SCC

 

[HRTKD]

Even though my two rooftop panels are identical to my two ground panels, I chose to use two solar charge controllers. I figured there will be times that I deploy only one panel on the ground or I might want to play around with connecting the ground panels in parallel rather than series.

I have a circuit breaker between the ground solar charge controller and the port for the ground panels. That keeps the system safe in case someone decides to do something nefarious with the port.

 

[Hedges]

Looks to me like one more string of 2 panels would fit within charge controller limits if oriented differently from the four on the roof, and this would be the most economical configuration.

Besides input voltage from PV being similar, it looks like 70A output and approximately 1000W is another limit (assuming 12V battery),
Also 50A max Isc.
4x 255W (STC) of panels is about 1000W, but actual production depends on orientation vs. sun and temperature.
If flat on the roof, they will produce less power much of the time, especially winter.

Paralleling another string of a different orientation would allow more watt hours without as much increase in peak.
Probably your roof mounts are fixed tilt (none), and the portable one you would aim at the sun.

If this is the panel, 9A Isc so 5 strings max; 3 is fine:

https://www.solarelectricsupply.com/fileuploader/download/download/?d=0&file=custom%2Fupload%2FCS6P-P_en.pdf

"MC4 models: several splitter pairs may be needed to parallel the strings of solar panels Maximum current per MC4 connector: 30A (the MC4 connectors are parallel connected to one MPPT tracker)"

Your charge controller may have two pairs MC4, but regardless all are just paralleled. When you have more than two strings, there should be a series fuse for each. You can get MC4 fuse holders.

 

[LanduytG]

Thanks all, figured I would need 2 if I did this. Not real sure I'm going to use the ground on yet. I have to find a good place to store it first. But the wiring is already there so it will be easy if and when I decide to do it

Greg.

 

[Trukinbear]

We split our array into two 3x3 arrays each with their own wiring and SCC. Glad I did as when one of my SCC went out on me I was still able to make 50% power while the SCC was out for warranty work. The failure of any one component can't knock me below 50% power, which not what I need is sure better than 0% power!