Anyone Installed Startco Earth Detection SE 704 for a 4160V 3-Phase Motor?

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The discussion focuses on the installation of the Startco Earth Detection SE 704 system for a 4160V, 1900 HP motor, specifically addressing nuisance tripping issues during motor startup. Participants inquire about the KVA code for the motor and whether the starting current is within the specifications of the Startco current transformers (CTs). The importance of considering the wye connection and third harmonic currents returning through the neutral is highlighted. Additionally, examining the CT output with an oscilloscope during startup is suggested to diagnose potential issues. The conversation emphasizes the need for careful analysis of motor windings' capacitance to earth and the CT's performance.
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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.
 
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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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