Siemens MICROMASTER 440 Operating Instructions Manual page 123

Issue 10/06
Compound braking
Compound braking current (entered in %)
P1236 =...
Defines DC level superimposed on AC waveform after exceeding DC-link voltage threshold
of compound braking. The value is entered in [%] relative to rated motor current (P0305).
(see also
Vdc controller ").
If P1254 = 0 :
Compound braking switch-on level
otherwise :
Compound braking switch-on level
Without Compound braking
⏐f⏐
f_set
i
u
DC-link
Dynamic braking
Dynamic braking
P1237 = ...
Dynamic braking is activated using parameter P1237 – the nominal (rated) duty cycle as
well as the switch-in duration of the braking resistor are also defined.
0 Inhibited
1 Load duty cycle 5 %
2 Load duty cycle 10 %
3 Load duty cycle 20 %
4 Load duty cycle 50 %
5 Load duty cycle 100 %
Using the dynamic brake, the regenerative feedback energy is transferred to the external
braking resistor using the chopper control (braking chopper); it is converted into thermal
energy (heat) in this resistor. This dynamic braking allows the drive to be braked in a
controlled fashion. This function is not available for sizes FX and GX.
~
MICROMASTER 440 Operating Instructions
6SE6400-5AW00-0BP0
P1236 = 0
f_act
t
t
U
DC_Comp
t
MM4
=
~
= ⋅
U 1.13
DC_Comp
= ⋅
U 0.98 r
DC_Comp
P1236 > 0
With Compound braking
⏐f⏐
f_set
f_act
i
u
DC-link
Chopper resistor
B+ B-
=
Chopper
control
3 Functions
0 %
⋅ = ⋅ ⋅
2 V . 1 13 2 P0210
mains
1242
t
t
t
0
~
123