A major benefit to the resistor grounded system is where there are motor or generators connected to the system, the resistor ground will limit the burning of iron. In systems with high short circuit availability, it will also help manage cable shield temperatures when the shield needs to carry...
Having to reset the lockout relay after any fault (electrical or thermal) will keep the motor from restarting after the event if some auto start signal is applied. If nothing else it simplifies the trip circuit by having all trips on a common trip bus. Like everything in protection and control...
I have attempted to attach a simplified single line diagram. There are four 13.8kV busses arranged in an "H" congfiguration. Each bus is supplied by a transformer. From each bus there are six underground feeders, I have shown one for simplicity. A three phase fault on the load side of any...
This question pertains to application of 3000A outdoor metal clad 15kV class ANSI switch gear. The available three fault current is calculated to be 38kA with an X/R = 37. As this substation has a resistor grounded medium voltage system and the SLG fault current is 4kA with an X/R<1.
The...
