SIM-Q MKII
Installation/operation instructions
DEIF A/S
Page 17 of 18
5 Determination of capacity within an application
5.1
Leakage capacitance in a connected network
Measuring of the leakage capacitance in a connected network using a voltmeter and an ammeter
(SL = PE).
Single phase:
CE = A/(V × 2 × phi × f). Phi is 3.14 and f is the frequency in Hz.
3 phases:
CE = A/(V ×
√3
× 2 × phi × f).
Example for a 3-phase system:
The current is measured to 30 A and the voltage is measured to 400 V:
CE = 30 A/400 V ×
√3
× 2 × 3.14 × 50 Hz = 137
μF per phase, total CE is 3
× 137
μF = 411
μF
.
For a 4-wire network, the CE total = CE × 4.
