To ground or not ground

[comet48]

Getting ready to install Growatt MIN11400TL-XH-US. The manual says "Since the inverter is transformer-less, the PV string connected to the inverter cannot be grounded, ensure that the PV module output is well insulated to ground."

Does this make sense? Worrisome because I'm on a metal roof.

Thanks

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[hwy17]

This is about grounding the positive or negative conductor, which you should not do.

You should still ground the panel frames, for sure.

 

[comet48]

Thank you - the answer I was hoping!