Ground Fault Protection on Ungrounded System

[kvramesh]

Hi,

I have an ungrounded transformer 23kV-1242Volts feeding a Variable frequency drive. We have 50/51 relay upstream and an outdoor breaker protecting the cables and transformers, VFDs. As the design requires, the system is ungrounded and does not include ground fault protection.

Is it required per NEC or ANSI/NEMA that ground fault protection (for personnel) is required for such systems? If so, how can that be accomplished?

Thanks for your help.

 

[jim dungar]

Is it required per NEC or ANSI/NEMA that ground fault protection (for personnel) is required for such systems? If so, how can that be accomplished?

Ground Fault protection for equipment is not required for this system.

Ground fault protection for personnel is not possible for this system.

 

[zog]

Hi,

I have an ungrounded transformer 23kV-1242Volts feeding a Variable frequency drive. We have 50/51 relay upstream and an outdoor breaker protecting the cables and transformers, VFDs. As the design requires, the system is ungrounded and does not include ground fault protection.

Is it required per NEC or ANSI/NEMA that ground fault protection (for personnel) is required for such systems? If so, how can that be accomplished?

Thanks for your help.

What country are you in? Those are weird voltages.

 

[kvramesh]

This system is installed in Chile. Yeah, they are weird voltages due to the altitude derating factors required at 17,000 feet.