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Startco Earth Detection SE 704

  1. Sep 26, 2011 #1
    Anyone ever install SE 704 Earth Detection (ground fault system)?
    4160V 3 phase
    1900 HP motor
    detection level 100 Ma
    resistance grounded supply max fault current 1 amp.

    Nuisance tripping when starting the motor.
  2. jcsd
  3. Sep 27, 2011 #2

    jim hardy

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    2018 Award

    what's KVA code on motor?

    is starting current within spec of that Startco gizmo's CTs?

    Wye connection? remember third harmonic all returns through neutral...CT needs to wrap it too.
    any idea of motor windings' capacitance to earth?

    examine CT output with a scope during a start, if it's 180 hz you have an interesting situation.

    just guesses

    old jim
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