Transformer Grounding

[jhemsone]

Hello, I have a XFMR being fed 2400 VAC which steps down to 480 VAC. XFMR is delta/wye. Secondary feeds two breakers which each control a VFD. How will the fact that I'm not using a "neutral" affect my grounding code? Do I still bond XO to case and still run grounding electrodes like normal. It seems silly but this threw me off. Thanks.

 

[infinity]

Yes the Wye secondary would be bonded the same way even if there is no neutral load.

 

[don_resqcapt19]

Since there are no line to neutral loads, there is no requirement to bond XO, however a lot of VFDs are not happy with ungrounded systems, and you would have to install a ground fault detector. Easier to just bond XO like you would if you had line to neutral loads.

 

[ggunn]

Since there are no line to neutral loads, there is no requirement to bond XO, however a lot of VFDs are not happy with ungrounded systems, and you would have to install a ground fault detector. Easier to just bond XO like you would if you had line to neutral loads.

I agree; it is better to bond X0 even if you do not use the neutral.