Requirement scenario of a 64REF and earth fault backup(51G)

[SS_EE]

Dear all,
Could you please let me know whether a 250kVA 0.48/15kV step-up transformer require the above protections? is there any recommendation from IEEE at which rating this protection is required?

This is a small take-off station of a 400 kWp ground mounted solar farm.

 

[jim dungar]

The National Electrical Code simply requires some type of monitoring of ungrounded systems or protection on solidly grounded systems, it is up to the designer to decide which functions to actually implement.

I can't remember employing a 64REF on a standard transformer as small as 250kVA.

 

[SS_EE]

The National Electrical Code simply requires some type of monitoring of ungrounded systems or protection on solidly grounded systems, it is up to the designer to decide which functions to actually implement.

I can't remember employing a 64REF on a standard transformer as small as 250kVA.

Hi Jim, thanks for the reply. in this case what will be your recommendation. the star configuration is on the HV side