Isaiah
Senior Member
- Location
- Baton Rouge
- Occupation
- Electrical Inspector
We have 15kV shielded cable (13.8kV system) from an outdoor substation with low resistance ground on the upstream transformer neutral. The associated CT interfaces with a protective relay that opens the line side CB.
Engineering says the circuit needs an EGC (#2/0) for fault current however NEC 250.190(C)(2) states the shield can be used as the EGC if a fault can be cleared without damaging the shield.
I’m just wondering where the relay needs to be set before the fault causes said damage.
Does anyone have experience with this?
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Engineering says the circuit needs an EGC (#2/0) for fault current however NEC 250.190(C)(2) states the shield can be used as the EGC if a fault can be cleared without damaging the shield.
I’m just wondering where the relay needs to be set before the fault causes said damage.
Does anyone have experience with this?
Sent from my iPhone using Tapatalk