Transformer Step Down 4160/600, Start-Delta Ground Issues

[Ricar2025]

Hi, All

I work for a power plant in a remote location. The plant generate at 4160V and use step down (Start-Delta) transformer to supply 600V to the MCC, We also use transformers 600V@208Y-120V for the building services. We are having internal ground issues between Ground to Neutral = 120VAC and Ground to Line = 120VAC. I would like to have some suggestions to solve this issue. We can upgrade the transformer with better configuration if need it. Thanks

 

[waross]

208Y-120V

The wye point is the neutral.
Ground the wye point.
eg: zero Volts from the wye point to ground 120 Volts from each phase to ground.

 

[LionelHutz]

The wye point of the 208/120V transformer is likely not grounded and one of the three lines might currently have a ground fault.