ABB ACS580 Series, Руководство по оборудованию

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Calculating the short-circuit current of the installation
Make sure that the short-circuit current of the installation is at least the value
given in the fuse table.
The short-circuit current of the installation can be calculated as follows:
I
k2-ph
=
2 · R
c
2
+ ( Z
k
+ X
c
)
2
U
where
Short-circuit current in symmetrical two-phase short-circuit Ik2-ph
Network line-to-line voltage (V) U
Cable resistance (ohm)
Rc
Zk = zk · Un2/Sn = transformer impedance (ohm) Zk
Transformer impedance (%) zk
Transformer rated voltage (V) Un
Nominal apparent power of the transformer (kVA) Sn
Cable reactance (ohm) Xc
Calculation example
Drive:
• ACS580-01-145A-4
• supply voltage = 410 V
Transformer:
• rated power S
n
= 600 kVA
• rated secondary voltage (supply for drive supply)
U
n
= 430 V
• transformer impedance z
k
= 7.2%
Supply cable:
• length = 170 m
• resistance/length = 0.398 ohm/km
• reactance/length = 0.082 ohm/km.
296 Technical data