Explanations on the short designations used: See
"Calculations for the Mains Connection" on page 260
7.4.2
Mains Short-Circuit Power
Definition of Mains Short-Circuit
Power
Power at nominal voltage U
N
between the phases and the maximum mains
short-circuit current I
K
at the connection point:
S
k
Short-circuit power of the mains
I
k
Short-circuit current
U
N
Mains voltage
Fig.7-7:
Mains Short-Circuit Power
For the mains short circuit power of the point of supply, ask your
local power supply company.
Definition of Mains Short-Circuit
Current
The mains short-circuit current I
K
results in the case of a short circuit at the
point of power supply connection.
X
K
System impedance
U
N
Mains voltage
Fig.7-8:
Mains Short-Circuit Current
UL requirement "maximum short-circuit current SCCR"
In the scope of CSA/UL, devices with C-UL listing may only be
operated at mains nodes with a symmetrical short-circuit current
smaller than the indicated value SCCR.
For the SCCR value, see the technical data of the device.
If necessary, use mains chokes to increase the system impe‐
dance and reduce the short-circuit current.
SCCR = I
K
Mains Classes According to Short-
Circuit Power
We basically distinguish mains classes graded according to mains short-cir‐
cuit power and system impedance:
U
N
= 400 V
U
N
= 480 V
Classification
S
k
X
k
L
k
X
k
L
k
MVA
mOhm
μH
mOhm
μH
1
Rigid mains
200
0,80
2,55
1,15
3,67
150
1,07
3,40
1,54
4,89
100
1,60
5,09
2,30
7,33
50
3,20
10,19
4,61
14,67
Bosch Rexroth AG
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
80/309
Project Planning of Mains Connection
