6600Vac capacitive fault current 1

[eljas]

Dear colleagues,
In the ship specification is stated that in case the capacitive fault current exceed 5A, the neutral to be provided with resistor (resistor earthed system).
I have been looking suitable ways for calculation, but there seems to be many different ways (?) to calculate capacitive fault current..pending of what source you are looking at.

One generally used formula based on the Thevenin's theorem (ABB handbook, absolut value, direct fault, no fault resistance) is: Ie = SQR(3) x 2 x pi x f x Co x U

f = 60Hz
Co = one phase capacity value (abt. 2 uF) based on cable maker's data and cable lengths
U = line voltage (6600ac)

,which gives an Ie value of abt.8A.

Are there any other aspects to be taken account for calculation?
Greatful for any further information and/or links/programs for defining correct value of capacitive fault current.

 

[RRaghunath]

eljas,
Taking cable capacitance alone is not sufficient. You need to consider transformer windings, motors, generator, bus duct and other such electrical equipment connected in the subject system.