Will this panel wiring work/be safe?

[Awsmits]

I have three 455W panels already roof-mounted, and wired in parallel. I'd like to raise the PV voltage coming to the controller. I would like to make the least wiring connection changes as possible to series connect two of the panels. Would the wiring to the panels shown in the photo accomplish this, and be safe?

 

[time2roll]

With 3 panels all need to be series or all parallel. No mixing as shown.
Before going all series check the controller max voltage is 20% higher than the combined Voc of the panels.

 

[chrisski]

If you need to raise the voltage and can’t have three panels in series, the other must be unused.

You could also get a fourth panel and go 2s2p.

 

[Awsmits]

Sorry, but please explain to me, a relative novice, why you cannot have 2 panels in series, and add a third panel in parallel. It’s probably obvious, but I don’t get it.

 

[time2roll]

The parallel panel will be at half the voltage as the series pair and will provide no power. Technically it can be connected... just that it will provide no power. May as well be disconnected. The parallel panel will be pushing 24 volts into 48 volts. Similar to trying to charge a 48v battery with a 24v charger.... just not going to go anywhere.

 

[MisterSandals]

A 3rd option (to all series or all parallel) would be to put 2 in series with your existing SCC and put the 3rd panel to a second smaller SCC.

Not pretty but having more options to choose from is always (usually?) better. Its not as bad as it sounds. Having a second system would provide some redundancy and be a good solution if partial shading is an issue/possibility. Similarly SCC's would play together nicely.

What is your existing SCC?

 

[Awsmits]

I have a Growatt All-in-One inverter, 24V, 3000W. The SCC can accept up to 150V of PV input. I wired my three panels in parallel thinking I would later add three more panels. I think what is best is for me to rewire the panels in series. Thanks all.

 

[Charleswgibbs]

I have a Growatt All-in-One inverter, 24V, 3000W. The SCC can accept up to 150V of PV input. I wired my three panels in parallel thinking I would later add three more panels. I think what is best is for me to rewire the panels in series. Thanks all.

The voc of three of your panels in series might be right on the edge of exceeding the 150v spec. Just something to be careful of especially as we get into colder weather.

 

[Awsmits]

Right! Thanks! The panel ratings of the VOC should be about 120-130 total, so hopefully that’s enough margin.