3 phase generators/transformers operating in parallel, current in the EGC

[kg4ase]

We have observed that a current on the grounding system exists when operating any of the Five (5x) existing Gensets that use solidly grounded Wye stator windings in concert with the Two (2) ESS (battery bank via charger inverter) Transformers that also use Wye primary windings some 1200 feet away. We have now correlated this current with some nuisance generator tripping (Neutral) when trying to bring a third generator online (in concert with ESS transformers).

Specifics:
If both ESS transformers are online, the combined value of the EGCs run with the 4,160 VAC feeder between 5030 to Pad mount MV Switchgear is 45A at 180Hz.
If one ESS transformer is isolated, this current is more-or-less “halved” (same Hz)
If both ESSs transformer primaries are isolated, the current stops.
Vice versa, if the ESSs transformers are online and the gensets are shut-down (i.e. when in ESS or ESS+PV mode) the current stops.

 

[Hoxton]

Could we have s single line diagram, please

 

[waross]

You may be seeing the cable charging current returning.
Is the power conveyed 1200 feet by cable?
Is the cable sheath grounded at both ends?
Or the inverter may be generating third order harmonics which are back feeding into the generator.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[kg4ase]

So how do I you the link to the files uploaded to the website

 

[kg4ase]

I have uploaded some documents.

https://files.engineering.com/getfi...3f-767dbc1569eb&file=Test_Results_10.1.19.pdf

https://files.engineering.com/getfi...a67f303b&file=Meck_Electric_-_Single_Line.pdf

https://files.engineering.com/getfi...ck-2380kW_SK20190924-1-Three_Line_Diagram.pdf

 

[waross]

Is the power conveyed 1200 feet by cable?
Is the cable sheath grounded at both ends?

Bill
--------------------
"Why not the best?"
Jimmy Carter