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Thread: Fuses vs Circuit breakers in switch gear

  1. #41
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    Quote Originally Posted by mbrooke View Post
    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.
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  2. #42
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    Quote Originally Posted by mivey View Post
    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?
    I'm in over my head...

  3. #43
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    Quote Originally Posted by mivey View Post
    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.
    I'm in over my head...

  4. #44
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    Quote Originally Posted by mbrooke View Post
    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.
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  5. #45
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    Quote Originally Posted by mivey View Post
    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?
    I'm in over my head...

  6. #46
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    Quote Originally Posted by mbrooke View Post
    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.
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  7. #47
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    Quote Originally Posted by mbrooke View Post
    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.
    BB+/BB=?

  8. #48
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    Quote Originally Posted by mivey View Post
    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.

    Quote Originally Posted by mivey View Post
    I would check for favorable conditions, especially on a 34.5kV system.

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

    Thanks
    I'm in over my head...

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