Engineering Information 06.2005
6SE7087-6QX70 (Version AE) Siemens AG
11-44 Compendium Motion Control SIMOVERT MASTERDRIVES
11.9.5 Selection of the braking resistor
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 kW kW kW
br br Invmax
.. .==−−=−
408 332 74
♦ For the mean braking power, the individual mean values are also
added together.
P P kW kW kW
br mean br Inv mean
==−−=−
0146 0 28 0 426.. .
♦ A 6SE7018-0ES87-2DC0 braking resistor of 80 Ω with P
20
= 5 kW
is necessary.
PkW
br max
.= 74 < 15 7 5
20
..⋅=PkW
PkW
br meen
= 0 426.
< PkW
20
45 111/. .=