Siemens Simovert Masterdrives Compendium page 944

Engineering Information
11.9.5 Selection of the braking resistor
11-44
The braking resistor is connected to the chopper of the rectifier unit.
During rating, it is assumed that the drives of the x and z axes can
brake simultaneously.
♦ The maximum braking power levels of the two inverters are
therefore added together.
∑
= = −
P P
br max br Inv
♦ For the mean braking power, the individual mean values are also
added together.
∑
=
P P
br mean br Inv mean
♦ A 6SE7018-0ES87-2DC0 braking resistor of 80 Ω with P
is necessary.
= 7 4
P . kW < 15
br max
= 0 426
P . kW
br meen
− = −
4 08 . kW 3 32 . kW
= − −
0 146 . kW 0 28 .
⋅ =
. P 7 5 . kW
20
=
< P / . 4 5 111 . kW
20
6SE7087-6QX70 (Version AE)
Compendium Motion Control
06.2005
7 4 . kW
= −
kW 0 426 . kW
= 5 kW
20
Siemens AG
SIMOVERT MASTERDRIVES