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

[dorymill]

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.

 

[jim hardy]

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