SIEMENS
7/60
Siemens D 21.4 · 2017
SINAMICS S120 drive system
Booksize format
Basic Line Modules in booksize format
7
■
Characteristic curves
(continued)
Braking power with external braking resistor
The following duty cycles are defined for the braking modules of
the 20 kW (25 hp) and 40 kW (50 hp) Basic Line Modules:
The maximum possible braking power
P
max
is calculated using
the following formula:
P
max
=
U
2
/
R
U
= Activation threshold
R
= Resistance value of the external braking resistor
The maximum braking power is achieved with the smallest
permissible resistance value. The maximum possible braking
power falls at larger resistance values.
Braking power of the 20 kW Basic Line Modules depending on the
connected braking resistor
When the recommended braking resistor is used, the following
values result for the maximum braking power or continuous
braking power:
Braking resistor 6SE7023-2ES87-2DC0
Resistance value = 20
Ω →
max. braking power = 30 kW;
continuous braking power = 5 kW
Braking power of the 40 kW Basic Line Modules depending on the
connected braking resistor
When the recommended braking resistor is used, the following
values result for the maximum braking power or continuous
braking power:
Braking resistor 6SE7028-0ES87-2DC0
Resistance value = 8
Ω →
max. braking power = 75 kW;
continuous braking power = 10 kW (limited by braking module)
G_D211_EN_00185b
2 x
P
rated
1.5 x
P
rated
P
d
300 s
46 s
3 s
P
t
G_D211_EN_00187a
Resistance
continuous braking power
Max. braking power
Power
P
35
25
kW
30
20
15
0
Ω
45
40
40
30
20
10
G_D211_EN_00188a
Resistance
continuous braking power
Max. braking power
Power
P
17.5
12.5
15
10
7.5
22.5
20
kW
0
Ω
80
60
40
20
© Siemens AG 2017