Parellel feeder relaying

[mbrooke]

4 13.8kv feeders from supply substation bus to source substation bus 4 miles away. Can I get away with directional over current and if so any general tips on how to set it? Or do I need something more advanced like step distance relaying for such an application?

 

[NewtonLaw]

More Questions

More Questions

4 13.8kv feeders from supply substation bus to source substation bus 4 miles away. Can I get away with directional over current and if so any general tips on how to set it? Or do I need something more advanced like step distance relaying for such an application?

Directional overcurrent should work just fine but as to setting them, I would want to know more about the configuration. 4 line in parallel, all 4 are express feeders, no other load attached until the reach "source substation? No additional line protection anywhere on the feeder circuits? MVA fault duty at the source?, X/R ration at the source? Wire size, configuration - three wire Wye, Delta, 4-wire Wye effectively grounded, expected load levels, capacity of each line, etc. ...

 

[mbrooke]

Directional overcurrent should work just fine but as to setting them, I would want to know more about the configuration. 4 line in parallel, all 4 are express feeders, no other load attached until the reach "source substation? No additional line protection anywhere on the feeder circuits? MVA fault duty at the source?, X/R ration at the source? Wire size, configuration - three wire Wye, Delta, 4-wire Wye effectively grounded, expected load levels, capacity of each line, etc. ...

What if there is some load attached before hitting the load substation?


The source is solidly grounded, line is 4 wire wye and the load substation transformers are delta-wye. About 10,000amps fault current max at the supply station.

 

[Phil Corso]

Brooke,

I'm presuming when when you say cables are "paralleled", you mean each cable has its own set of send and receive breakers! That is, individual feeders can be switched in or out! Am I correct?

Regards, Phil Corso

 

[mbrooke]

Brooke,

I'm presuming when when you say cables are "paralleled", you mean each cable has its own set of send and receive breakers! That is, individual feeders can be switched in or out! Am I correct?

Regards, Phil Corso

Correct, 4 individual bays with their own breaker at the supply station and 4 individual bays with their own breakers at the source substation (plus separate cap and transformer breakers). Each feeder can be switched in and out independently of the others.

 

[Phil Corso]

Additional questions:

1) Are cables sheathed?

2) If so, are they (the sheaths) cross-connected at specifc intervals for the entire length?

Phil