Growatt 5000 48 volt panel sizing

[G755]

I ordered a growatt Sf 5000 with the transformer.
The mppt is 434 volts and 18 amps.
How many panels can I hook up in series on one string if each pannel VOC is 49.6 volts and the ISC is 13.45 amps and the watts is 530? I think the answer is 8 but since this is my first off grid set up, I want to check with you.
Second question is since it is in series can I really just plug it straight into the growatt inverter. OR so I need a fuse and a cut off switch?
Thanks Greg

 

[sunshine_eggo]

You need to allow 10-20% margin for cold temperature voltage increases. leaves you with about 34 volts, but that might be tight.

Your panels have a temperature coefficient, -X%/°C. As an example, X is commonly around 0.33, so at freezing, -25°C * -0.33%/°C = 8.25%

49.6 * 8 * 1.0825 = 429.5V - just under the 434V limit.

If it gets colder than freezing, you should probably limit it to 7S panels.

 

[G755]

You need to allow 10-20% margin for cold temperature voltage increases. leaves you with about 34 volts, but that might be tight.

Your panels have a temperature coefficient, -X%/°C. As an example, X is commonly around 0.33, so at freezing, -25°C * -0.33%/°C = 8.25%

49.6 * 8 * 1.0825 = 429.5V - just under the 434V limit.

If it gets colder than freezing, you should probably limit it to 7S panels.

Thanks...