Using electricity from Growatt for water heater - how do ensure safety?

[Riley]

So I am a bit confused with the meaning of "grounded," information says a water heater must be plugged in a grounded outlet to ensure safety. Growatt has three interfaces, and my cord is a three-prong (I used Will's method, connected an extension cord to Growatt), but I don't get how I am grounded because apparently there is nothing attached to the ground in an RV except the tires. Also, in the manual of my 6-gallon electric water heater, it is against using an extension cord, but that's my power source.

 

[svsagres]

In the case of an RV, the ground should be bonded to the chassis. When you're not on shore power, then the neutral should be bonded to the ground, at the inverter only. When connected to shore power, that connection needs to be lifted. I don't know about the growatt inverters handle it, but the Victron inverters do have a relay that deals with this automatically.