Fuses vs Circuit breakers in switch gear

[mivey]

I honestly do not know

Though I doubt I will exceed 10,000amps.

Current limiting fuses are often used to reduce risk of transformer rupture for faults closer to the substation.

I have never used them on outdoor MV for arc flash reduction but I suppose you could if you found a benefit.

 

[mbrooke]

None that I know of but I think about it with lightly loaded transformers and higher voltages.

At what voltage does it become a concern?

 

[mbrooke]

Current limiting fuses are often used to reduce risk of transformer rupture for faults closer to the substation.

I have never used them on outdoor MV for arc flash reduction but I suppose you could if you found a benefit.

Seen some POCOs add CLF on pole pigs near the sub- that would make sense.

 

[mivey]

At what voltage does it become a concern?

I don't really worry about systems below at 12 kV and below although it is possible.

 

[mbrooke]

I don't really worry about systems below at 12 kV and below although it is possible.

What would you say about 25kv or maybe even 34.5kv? Also can a modified saturation curve prevent it?

 

[mivey]

Seen some POCOs add CLF on pole pigs near the sub- that would make sense.

The smaller the transformer the greater the risk but usually starting around 4kA to 6kA of fault can be a concern target.

 

[mivey]

What would you say about 25kv or maybe even 34.5kv? Also can a modified saturation curve prevent it?

I would check for favorable conditions, especially on a 34.5kV system.

Don't know about the sat curve, would have to check.

 

[mbrooke]

The smaller the transformer the greater the risk but usually starting around 4kA to 6kA of fault can be a concern target.

Did not know this- much thanks. Up to 10ka I will just spec a K or T link... I never gave this much thought.

I would check for favorable conditions, especially on a 34.5kV system.

Don't know about the sat curve, would have to check.

Thanks