DC grounding electrode conductor (GEC) on single phase inverters

[philly]

I know the NEC( dont have code book in front of me) required a DC grounding electrode and conductor to be landed on the designated DC grounding electrode terminal inside of the inverter. I've seen most larger 3-phase inverers have a designated grounding electrode on the DC side of the inverter.

What about a single phase inverter that only has one ground terminal? Do we use this ground terminal to land the DC grounding electrode? Do we use the same terminal to land the EGC from the upstream main panel as well?

Also if I have (3) inverters side by side, can I installe one grounding electrode in the ground and then have a grounding electrode that runs to all 3 inverter by means of tapping a main grounding electrode? I guess this would have to comply with the rules of article 250 for tapping a GEC?

 

[philly]

Since these single phase inverters are a "transformerless" inverter I read some articles that highlighted potential issues with grounding due to the fact that ground currents could pass between the AC and DC system due to the fact there is no transformer to isolate the 2 systems?

Is this an potential item to be concerned with when combining the grounds of the DC and AC system on a single terminal in the inverter?

 

[ggunn]

Since these single phase inverters are a "transformerless" inverter I read some articles that highlighted potential issues with grounding due to the fact that ground currents could pass between the AC and DC system due to the fact there is no transformer to isolate the 2 systems?

Is this an potential item to be concerned with when combining the grounds of the DC and AC system on a single terminal in the inverter?

Transformerless inverters use ungrounded arrays, i.e., the negative conductor to the array is not grounded. That only affects the current carrying conductors; the EGC (module frames and rails) is the same as for systems with transformers in the inverters.